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Traditionally, developing inhaled drug formulations relied on trial and error, yet recent technological advancements have deepened the understanding of 'inhalation biopharmaceutics' i.e. the processes that occur to influence the rate and extent of drug exposure in the lungs. This knowledge has led to the development of new in vitro models that predict the in vivo behavior of drugs, facilitating the enhancement of existing formulation and the development of novel ones. Our prior research examined how simulated lung fluid (SLF) affects the solubility of inhaled drugs. Building on this, we aimed to explore drug dissolution and permeability in lung mucosa models containing mucus. Thus, the permeation of four active pharmaceutical ingredients (APIs), salbutamol sulphate (SS), tiotropium bromide (TioBr), formoterol fumarate (FF) and budesonide (BUD), was assayed in porcine mucus covered Calu-3 cell layers, cultivated at an air liquid interface (ALI) or submerged in a liquid covered (LC) culture system. Further analysis on BUD and FF involved their transport in a mucus-covered PAMPA system. Finally, their dissolution post-aerosolization from Symbicort® was compared using 'simple' Transwell and complex DissolvIt® apparatuses, alone or in presence of porcine mucus or polymer-lipid mucus simulant. The presence of porcine mucus impacted both permeability and dissolution of inhaled drugs. For instance, permeability of SS was reduced by a factor of ten in the Calu-3 ALI model while the permeability of BUD was reduced by factor of two in LC and ALI setups. The comparison of dissolution methodologies indicated that drug dissolution performance was highly dependent on the setup, observing decreased release efficiency and higher variability in Transwell system compared to DissolvIt®. Overall, results demonstrate that relatively simple methodologies can be used to discriminate between formulations in early phase drug product development. However, for more advanced stages complex methods are required. Crucially, it was clear that the impact of mucus and selection of its composition in in vitro testing of dissolution and permeability should not be neglected when developing drugs and formulations intended for inhalation., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: [Snezana Radivojev, Lukas Kargl, Joana T. Pinto, Eleonore Fröhlich and Amrit Paudel are employees of the Research Center Pharmaceutical Engineering GmbH, which received funding for their work from Chiesi Farmaceutici. Maria Malmlöf and Per Gerde are employed by Inhalation Sciences AB.]., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Antibiotics and bronchodilator drugs can be used together in respiratory distress caused by bacterial infections. Levofloxacin (LVX) and Salbutamol (SLB) can be used simultaneously in respiratory distress. However, there have been no investigations on how the concurrent use of SLB can affect the pharmacokinetics of LVX in rats., Objective: The purpose of this study was to investigate the influence of SLB on the plasma and lung pharmacokinetics of LVX in rats., Methods: A total of 132 rats were randomly assigned to two groups: LVX (n=66) and LVX+SLB (n=66). LVX (intraperitoneal) and SLB (oral) were administered to rats at doses of 50 and 3 mg/kg, respectively. The concentrations of LVX in the plasma and lungs were determined through the utilization of high-performance liquid chromatography along with UV. Pharmacokinetic parameters were assessed by non-compartmental analysis., Results: The area under the curve from 0 to 16 h (AUC 0-16 ), terminal elimination half-life, volume of distribution, total body clearance, and peak concentration of LVX in the plasma were 42.57 h*μg/mL, 2.32 h, 3.91 L/kg, 1.17 L/h/kg, and 23.96 μg/mL, respectively. There were no alterations observed in the plasma and lung pharmacokinetic parameters of LVX when co-administered with SLB. The AUC 0-16 lung/AUC 0-16 plasma ratios of LVX were 1.60 and 1.39 after administration alone and co-administration with SLB, respectively., Conclusion: The concentration of LVX in lung tissue was higher than that in plasma. SLB administration to rats did not affect the plasma and lung pharmacokinetics and lung penetration ratio of LVX. There is a need to reveal the change in the pharmacokinetics of LVX after multiple administration of both drugs and after administration of SLB by different routes., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Salbutamol was included in the prohibited list of the World Anti-Doping Agency (WADA) in 2004. Although systemic intake is banned, inhalation for asthma is permitted but with dosage restrictions. The WADA established a urinary concentration threshold to distinguish accordingly prohibited systemic self-administration from therapeutic prescription by inhalation. This study aimed at evaluating the ability of the WADA threshold to differentiate salbutamol therapeutic use from violation of antidoping rules. Concentration-time profile of salbutamol in plasma and its excretion in urine was characterized through a model-based meta-analysis of individual and aggregate data collected after administration of a large range of doses following different modes of administration and under a variety of conditions. The developed model adequately fitted salbutamol plasma and urine concentration-time profiles of the 13 selected studies. Model-based simulations confirmed that a wide range of salbutamol urine concentrations might be measured after drug intake. Although violation of the WADA Code can be strongly suspected in individuals showing very high salbutamol urine concentrations, uncertainty remains for values close to the WADA threshold as they can be compatible with both permitted therapeutic use and violation. Although not entirely discriminant, the current WADA rule is globally supported by our appraisal. It could be further improved by a slight and reasonable adjustment of inhaled daily dosages allowed for therapeutic use. Our model might help antidoping experts in the evaluation of suspected doping cases through confronting the athlete's urine measurements with their allegations about salbutamol treatment., (© 2022 The Authors. CPT: Pharmacometrics & Systems Pharmacology published by Wiley Periodicals LLC on behalf of the American Society for Clinical Pharmacology and Therapeutics.)

Introduction: The aim of the work was to formulate salbutamol sulfate (SB) microspheres by using superhydrophobic surface (SHS) under different processing factors for improving its encapsulation efficiency, controling its release rate, and hence enhancing its bioavailability., Methods: Cross-linked microspheres of chitosan (CN) and carrageenan (KN) were made on a SHS under a glutaraldehyde-saturated atmosphere. The formulations were designed and optimized based on 4 2 factorial design. Percentage encapsulation efficiency (%EE), particle size, swelling ratio, and in vitro release rate were characterized, and the in vivo performance of optimized formula was investigated in beagle dogs., Results: The results showed that the prepared microspheres have a high %EE (97.11±0.78%) for F13. The swelling ratio was 4.2 at the end of the 8 hours for the optimized formula, and the in vitro release rate was controlled for 12 hours. In vivo study verified that there was a 1.61-fold enhancement in SB bioavailability from optimized formula (F13) compared to market tablet., Conclusion: The study suggested that microspheres prepared from CN/KN crosslinking on an SHS using glutaraldehyde atmosphere is a promising technique that can encapsulate and sustain the release of water-soluble drugs such as SB in addition to improving its in vivo pharmacokinetic profile., Competing Interests: The authors declare no conflicts of interest for this work., (© 2021 Gaber et al.)

Bronchodilators dilate the bronchi and increase lung volumes, thereby improving respiratory physiology in patients with chronic obstructive pulmonary disease (COPD). However, their effects on sevoflurane kinetics remain unknown. We aimed to determine whether inhaled salbutamol affected the wash-in and wash-out kinetics of sevoflurane and the occurrence of early postoperative pulmonary complications (PPCs) in patients with COPD undergoing elective surgery. This randomized, placebo-controlled study included 63 consecutive patients with COPD allocated to the salbutamol (n = 30) and control groups (n = 33). The salbutamol group received salbutamol aerosol (2 puffs of ~200 μg) 30 min before anesthesia induction and 30 min before surgery completion. The control group received a placebo. Sevoflurane kinetics were determined by collecting end-tidal samples from the first breaths at 1, 2, 3, 4, 5, 7, 10, and 15 min before the surgery (wash-in) and after closing the vaporizer (wash-out). PPCs were recorded for 7 days. The salbutamol group had higher end-tidal to inhaled sevoflurane ratios (p<0.05, p<0.01) than the control group, from 3 to 10 min during the wash-in period, but no significant differences were observed during the wash-out period. The arterial partial pressure of oxygen to the fraction of inhaled oxygen was significantly higher in the salbutamol group at 30 (320.3±17.6 vs. 291.5±29.6 mmHg; p = 0.033) and 60 min (327.8±32.3 vs. 309.2±30.5 mmHg; p = 0.003). The dead space to tidal volume ratios at 30 (20.5±6.4% vs. 26.3±6.0%, p = 0.042) and 60 min (19.6±5.1% vs. 24.8±5.5%, p = 0.007) and the incidence of bronchospasm (odds ratio [OR] 0.45, 95% confidence interval [CI] 0.23-0.67, p = 0.023) and respiratory infiltration (OR 0.52, 95% CI, 0.40-0.65, p = 0.017) were lower in the salbutamol group. In patients with COPD, salbutamol accelerates the wash-in rate of sevoflurane and decreases the occurrence of postoperative bronchospasm and pulmonary infiltration within the first 7 days., Competing Interests: The authors declare no potential interests exist.

Dry powder inhaler (DPI) is recognized as the first choice for lung diseases' treatment. However, it lacks a universal way for DPI formulation development. Fine lactose is commonly added in DPIs to improve delivery performance; however, the fine ratio-dependent mechanism is unclear. Therefore, the objective of this study is to explore the influence of fine lactose ratio on DPI powder properties and aerodynamic behavior, and the fine lactose ratio-dependent mechanism involved during powder fluidization and lung deposition. Here salbutamol sulfate was used as a model drug, Lactohale® 206 as coarse carrier, and Lactohale® 300 as fine component; the mixtures were prepared at 1% drug content, with fine content up to 20%. It was shown that with the fine addition, flowability of the mixtures was improved, interaction among particles was increased, and the presence of fines could help to improve DPI's aerosolization performance. When the fines added were less than 3%, the "active site" hypothesis played a leading role. When the added fines were over 3% but less than 10%, fluidization enhancement mechanism was more important. After the added fines reaching 10%, aggregate mechanism started to dominate. However, FPF cannot be further increased once the fines reached 20%. Moreover, the correlations between FPF and dynamic powder parameters were verified in ternary mixtures, and cohesion had a greater impact on FPF than that of flowability. In conclusion, adding lactose fines is an effective way to improve lung deposition of DPI, with the concrete mechanism lactose fine ratio dependent.

As of 2020, use of beta 2 -agonist salmeterol is restricted by the World Anti-Doping Agency (WADA) and is only permitted by inhalation at therapeutic doses not exceeding 200 μg in 24 h. In contrast to beta 2 -agonists salbutamol and formoterol, WADA has not established a urine threshold for salmeterol despite its muscle hypertrophic actions observed in animals. Herein, we investigated plasma (0-4 h) and urine (0-24 h) concentrations (by ultra-high-performance liquid chromatography-tandem mass spectrometry [UHPLC-MS/MS]) of salmeterol and α-hydroxysalmeterol after dry powder inhalation at supratherapeutic (400 μg) and high therapeutic (200 μg) doses, and after seven consecutive days of therapeutic inhalation (200 μg × day -1 ) in 11 healthy endurance-trained men. During each trial, participants inhaled salmeterol before 1½ h moderate-intensity cycling. Mean ± SD maximum urine concentrations of salmeterol unadjusted for specific gravity reached 4.0 ± 1.6, 2.1 ± 1.5, and 2.2 ± 1.1 ng × ml -1 for 400 μg, 200 μg, and seven consecutive days of 200 μg, respectively, with corresponding maximum urine concentrations of α-hydroxysalmeterol being 11.6 ± 6.1, 5.7 ± 4.6, and 6.5 ± 2.6 ng × ml -1 . Within the relevant window for doping control (first 6 h post-inhalation), the present data (119 samples), along with 64 biobank urine samples, showed that a combined salmeterol and α-hydroxysalmeterol urine threshold with equal cut-offs of 3.3 ng × ml -1 was superior to a salmeterol-only threshold to discriminate therapeutic (200 μg) from supratherapeutic use (400 μg) with a sensitivity of 24% with 0% false positives when applying the WADA technical document (TD2019DL.v2) method of specific gravity adjustment. Thus, a combination of urine salmeterol and α-hydroxysalmeterol concentrations may be suitable for discriminating between therapeutic and supratherapeutic prohibited inhalation of salmeterol., (© 2020 John Wiley & Sons Ltd.)

Medicine regulators require the melting points for crystalline drugs, as they are a test for chemical and physical quality. Many drugs, especially salt-forms, suffer concomitant degradation during melting; thus, it would be useful to know if the endotherm associated with melt degradation may be used for characterising the crystallinity of a powder blend. Therefore, the aim of this study was to investigate whether melt-degradation transitions can detect amorphous content in a blend of crystalline and amorphous salbutamol sulphate. Salbutamol sulphate was rendered amorphous by freeze and spray-drying and blended with crystalline drug, forming standards with a range of amorphous content. Crystalline salbutamol sulphate was observed to have a melt-degradation onset of 198.2±0.2°C, while anhydrous amorphous salbutamol sulphate prepared by either method showed similar glass transition temperatures of 119.4±0.7°C combined. Without the energy barrier provided by the ordered crystal lattice, the degradation endotherm for amorphous salbutamol sulphate occurred 50°C below the melting point, with an onset of 143.6±0.2°C. The enthalpies for this degradation transition showed no significant difference between freeze- and spray-dried samples (p>0.05). Distinct from convention, partial integration of the crystalline melt-degradation endotherm was applied to the region 193-221°C which had no contribution from the degradation of amorphous salbutamol sulphate. The linear correlation of these partial areas with amorphous content, R 2 =0.994, yielded limits of detection and quantification of 0.13% and 0.44% respectively, independent of drying technique. Melt-degradation transitions may be re-purposed for the measurement of amorphous content in powder blends, and they have potential for evaluating disorder more generally.

Prediction of human pharmacokinetics is important in the preclinical stage. Values for total clearance of compounds from plasma should be one of the most important pharmacokinetic parameters for predictions. Although several physiological and empirical methods including single-species allometry for prediction of values for human clearance of compounds using humanized-liver mice have been reported, further improvement of prediction accuracies would be still expected. To optimize these approaches, we proposed methods for unbound intrinsic clearance in virtually 100% humanized-liver mouse by incorporating unbound plasma fractions of compounds in differently humanized-liver mice. Comparisons of prediction accuracies of values for human clearance of 15 model compounds were performed among our current physiological and previously reported models and single-species allometry using humanized-liver mice. Incorporation of the actual unbound plasma fractions of compounds and correction of residual mice hepatocyte in humanized-liver mice showed comparable prediction accuracy to that by single-species allometry. After exclusion of 3 compounds with large species differences in values of clearance and unbound plasma fractions between mice and humans out of 15 compounds, prediction accuracies were improved in the methods investigated. The previously and present reported physiological methods could show the good prediction accuracy of values for clearance of drugs from plasma., Competing Interests: Declaration of competing interest The authors declare that there are no conflicts of interest., (Copyright © 2020 The Japanese Society for the Study of Xenobiotics. Published by Elsevier Ltd. All rights reserved.)

The rapid absorptive clearance of drugs delivered to the airways of the lungs means that many inhaled medicines have a short duration of action. The aim of this study was to investigate whether forming polar ion-pairs can modify drug absorption to slow down clearance from the airways. Salbutamol was used as a model drug and was formulated as ion-pairs in an aqueous solution with three negatively charged hydrophilic counterions: sulfate (molecular weight (MW) 142), gluconate (MW 218), and phytate (MW 736) (association constants of 1.57, 2.27, and 4.15, respectively) and one negatively charged hydrophobic counterion, octanoate (MW 166) (association constant, 2.56). All of the counterions were well tolerated by Calu-3 human bronchial epithelial cells when screened for toxicity in vitro using conditions that in silico simulations suggested maintain >80% drug-counterion association. The transport of salbutamol ion-pairs with higher polar surface area (PSA), i.e., the sulfate (PSA 52%), gluconate (PSA 50%), and phytate (PSA 79%) ion-pairs, was significantly lower compared to that of the drug alone (PSA 30%, p < 0.05). In contrast, the octanoate ion-pair (PSA 23%) did not significantly alter the salbutamol transport. The transport data for the gluconate ion-pair suggested that the pulmonary absorption half-life of the ion-paired drug would be double that of salbutamol base, and this illustrates the promise of increasing drug polarity using noncovalent complexation as an approach to control drug delivery to the airways of the lungs.

Background: Coordination between actuation of a pressurized metered dose inhaler (pMDI) and inhalation is a critical manoeuvre that many patients fail to perform correctly. pMDIs connected to spacers do not require hand-lung coordination. This study evaluated the relative lung and systemic bioavailability and oropharyngeal deposition of salbutamol post-inhalation from Ventolin® Evohaler® (GlaxoSmithKline) either alone following verbal inhaler technique counselling (VC) or connected to a newly improved Able Spacer® (AS)., Methods: In a two-period, randomized crossover study, 16 healthy adults inhaled 2 × 100 µg salbutamol puffs (1 min gap) from Ventolin using VC or AS. Immediately after each puff inhalation, each subject gargled with 20 mL water for oropharyngeal deposition (OD) determination. Urine samples were collected 0.5 h (pre-) and 0.5, 1.0 and 2.0 h post-inhalation. Urine was then pooled 2-24 h post-inhalation. The relative lung bioavailability (0-0.5 h urinary salbutamol excretion - USAL0.5) and systemic bioavailability (0-24 h urinary excretion of salbutamol and its metabolite - USALMET24) were determined. A one week washout separated VC and AS use., Results: The mean (SD) USAL0.5 of VC and AS was 5.36 (4.48) and 12.80 (10.83) µg, respectively. The mean (SD) OD was 11.35 (3.37) and 0.48 (0.30) µg, respectively. VC and AS were significantly different in USAL0.5 and OD (p<0.001). USALMET24 was comparable (p>0.05)., Conclusions: Compared with VC, AS doubled the inhaled salbutamol lung dose and minimised its precipitation in the oral cavity. The results suggest this inhalation aid can add therapeutic and safety benefits particularly in patients with continued pMDI technique issues despite repeated VC., Competing Interests: Declaration of Competing Interest W.G.A. is an Academic Researcher in the inhaled respiratory medicine and inhaler devices areas. He has received unconditional travel grants from Clement Clarke International Limited to present his research work at ATS, BTS, ERS and ISAM conferences. G.A.O. has no conflict of interest to declare. M.S. is the Chief Technology Officer (CTO) at Clement Clarke International Limited, UK., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: Intravenous salbutamol is used to treat children with refractory status asthmaticus, however insufficient pharmacokinetic data are available to guide initial and subsequent dosing recommendations for its intravenous use. The pharmacologic activity of salbutamol resides predominantly in the (R)-enantiomer, with little or no activity and even concerns of adverse reactions attributed to the (S)-enantiomer., Objective: Our aim was to develop a population pharmacokinetic model to characterize the pharmacokinetic profile for intravenous salbutamol in children with status asthmaticus admitted to the pediatric intensive care unit (PICU), and to use this model to study the effect of different dosing schemes with and without a loading dose., Methods: From 19 children (median age 4.9 years [range 9 months-15.3 years], median weight 18 kg [range 7.8-70 kg]) treated with continuous intravenous salbutamol at the PICU, plasma samples for R- and S-salbutamol concentrations (111 samples), as well as asthma scores, were collected prospectively at the same time points. Possible adverse reactions and patients' clinical data (age, sex, weight, drug doses, liver and kidney function) were recorded. With these data, a population pharmacokinetic model was developed using NONMEM 7.2. After validation, the model was used for simulations to evaluate the effect of different dosing regimens with or without a loading dose., Results: A two-compartment model with separate clearance for R- and S-salbutamol (16.3 L/h and 8.8 L/h, respectively) best described the data. Weight was found to be a significant covariate for clearance and volume of distribution. No other covariates were identified. Simulations showed that a loading dose can result in higher R-salbutamol concentrations in the early phase after the start of infusion therapy, preventing accumulation of S-salbutamol., Conclusions: The pharmacokinetic model of intravenous R- and S-salbutamol described the data well and showed that a loading dose should be considered in children. This model can be used to evaluate the pharmacokinetic-pharmacodynamic relationship of intravenous salbutamol in children, and, as a next step, the effectiveness and tolerability of intravenous salbutamol in children with severe asthma.

Background: For the treatment of respiratory disease, inhaled drug delivery aims to provide direct access to pharmacological target sites while minimizing systemic exposure. Despite this long-held tenet of inhaled therapeutic advantage, there are limited data of regional drug localization in the lungs after inhalation. The aim of this study was to investigate the distribution and retention of different chemotypes typifying available inhaled drugs [slowly dissolving neutral fluticasone propionate (FP) and soluble bases salmeterol and salbutamol] using mass spectrometry imaging (MSI). Methods: Salmeterol, salbutamol, and FP were simultaneously delivered by inhaled nebulization to rats. In the same animals, salmeterol- d 3 , salbutamol- d 3 , and FP- d 3 were delivered by intravenous (IV) injection. Samples of lung tissue were obtained at 2- and 30-minute postdosing, and high-resolution MSI was used to study drug distribution and retention. Results: IV delivery resulted in homogeneous lung distribution for all molecules. In comparison, while inhalation also gave rise to drug presence in the entire lung, there were regional chemotype-dependent areas of higher abundance. At the 30-minute time point, inhaled salmeterol and salbutamol were preferentially retained in bronchiolar tissue, whereas FP was retained in all regions of the lungs. Conclusion: This study clearly demonstrates that inhaled small molecule chemotypes are differentially distributed in lung tissue after inhalation, and that high-resolution MSI can be applied to study these retention patterns.

Background: Chronic diseases such as diabetes, asthma, and heart disease are the leading causes of death in developing countries. Public health plays an important role in preventing such diseases to improve individuals' quality of life. Conventional dosage schemes used in public health to cure various diseases generally lead to undesirable side effects and renders the overall treatment ineffective. For example, a required concentration of drug cannot reach the lungs using conventional methods to cure asthma. Microspheres have emerged as a confirmed drug-delivery system to cure asthma., Method: In this paper, a salbutamol-loaded poly lactic acid-co-glycolic acid-polyethylene glycol (PLGA-PEG) microsphere (SPP)-based formulation was prepared using a Buchi B-90 nanospray drier. Face-centered central composite design (CCD) was applied to optimize the spray-drying process., Results: The drug content and product yield were found to be 72%±0.8% and 86%±0.4%, respectively; drug release (91.1%) peaked for up to 12 hrs in vitro. Microspheres obtained from the spray dryer were found to be shriveled. The experiments were carried out and verified using various groups of rabbits. In our study, the particle size (8.24 µm) was observed to be an essential parameter for drug delivery. The in vivo results indicated that the targeting efficacy and drug concentration in the lung was higher with the salbutamol-loaded PLGA-PEG SPP formulation (1,410.1±10.11 µg/g, 15 mins), as compared to the conventional formulation (92±0.56 µg/g, 10 min). The final product was stable under 5°C±2°C, 25°C±2°C, and 40°C±2°C/75%±5% relative humidity. In addition, these co-polymers have a good safety profile, as determined by testing on human alveolar basal epithelium A549 cell lines., Conclusion: Our results prove that microspheres are an alternative drug-delivery system for lung-targeted asthma treatments used in public health., Competing Interests: The authors declare no conflicts of interest., (© 2019 SreeHarsha et al.)

Background: The impact of inhalers' postdispensing, real-life temperature and relative humidity (RH) environments on their delivered dose (DD) and aerodynamic particle size distribution (APSD) is usually overlooked. This work evaluated the salbutamol DD and APSD of Ventolin ® Evohaler ® (V) inhalers already been used and stored by respiratory patients. Methods: Adult patients, prescribed V for ≥3 months before study enrollment, were dispensed both new V to use and portable, handheld electronic temperature and RH data loggers to keep close to the given V before returning them both after 2-3 weeks. Patients' enrollment took place during summer (VS) and winter (VW) seasons. The returned V was then in vitro evaluated using the Next Generation Impactor, and compared with control V (VC) counterparts stored under 21°C and 46% RH. Results: The VS survived in fluctuating habitats of 21.2°C-40.4°C and 16.2%-63.2% RH, which significantly ( p  < 0.05) decreased the salbutamol DD from 80.4 to 70.5 μg compared with VC. This 12.3% DD reduction was accompanied with a decrease in the fine particle dose from 26.2 to 20.4 μg ( p  < 0.05), and an increase in the mass median aerodynamic diameter from 2.3 to 2.5 μm ( p  < 0.05). The VW and VC had equivalent DD and APSD. Conclusion: Patients using V are expected to receive smaller lung doses during the hot summer season compared with intentionally well-kept VC. To have equivalent lung deposition, V users should be advised to retain their inhalers around 20°C with minimal daily environmental fluctuations during summer times.

Dry powder inhalers have attracted more interest over the years in every aspect related to them. Interestingly, when focusing on the effects of particle morphology of the active or carrier (excipient), it is generally regarded particle size and shape to influence drug availability of aerosolized particles. However, to date, few studies have examined the effect of texture, i.e., roughness, on this relationship. The main objective of the present work is to gain a closer understanding of the influence of carrier morphology on the aerosolization performance of dry powder inhaler formulations. Image analysis and microscopy were used to visualize the aerosolization process. It is considered that the scale of morphological features on the surface of the carrier particles is responsible for the dispersion of the powder formulation, separation of the drug/carrier, and entrainment from a dry powder inhaler. Thus, for this study, the carrier particles of different surface roughness were mixed with micronized salbutamol sulphate. Aerosolization in vitro testing was used to evaluate the performance. The results indicate a connection between the qualitative surface roughness of coarse carriers and aerosolization performance during powder dispersibility. This investigation demonstrated that indeed, powder dispersion, a dynamic process, is influenced by the scale of the carrier morphology.

Background: There has been a growing trend toward delivering aerosolized medications using high-flow nasal cannula (HFNC). In some cases, patients who do not require high-flow oxygen to maintain adequate oxygenation may benefit from aerosol delivery while receiving low-flow oxygen via HFNC. The objective of this study was to quantify and compare the relative pulmonary and systemic delivery of salbutamol, with 2 different nebulizers, in patients with COPD receiving low-flow oxygen therapy through an HFNC., Methods: Subjects were randomized to receive study doses of 5 mg salbutamol nebulized by either a jet nebulizer or a vibrating mesh nebulizer with a T-piece or spacer on days 1, 3, and 5 of admission. Subjects using the large spacer also received 2 puffs (100 μg each) of salbutamol via a pressurized metered-dose-inhaler prior to the nebulizer dose. Urinary salbutamol excretion 30 min post-inhalation and pooled samples of urinary salbutamol excretion up to 24 h post-inhalation were measured. On day 2, ex vivo studies were performed with salbutamol collected on filters placed between the HFNC and nebulizer, with drug eluted from filters and analyzed to determine inhaled dose., Results: Twelve subjects (6 females), age 51.3 ± 11.2 y, were included. The vibrating mesh nebulizer demonstrated higher urinary salbutamol excretion at 30 min and 24 h post-inhalation compared to a jet nebulizer ( P = .001 and P = .02, respectively). No significant difference was found between the T-piece and large-spacer configurations, even though the spacer provided a significantly larger emitted aerosol dose at the opening of the HFNC ( P = .002)., Conclusions: Aerosolized medication could be efficiently combined with low-flow oxygen, via HFNC, in COPD subjects without the need to interrupt the gas supply. The vibrating mesh nebulizer delivered larger doses to subjects compared to the jet nebulizer. However, there was no benefit of using the large spacer with HFNC in low-flow delivery, because the small inner diameter of the HFNC does not allow larger aerosol droplet sizes (preserved by the spacer) to reach the subject., (Copyright © 2019 by Daedalus Enterprises.)

The aim of the present study was to demonstrate the effect of inhalation-flow, inhalation-volume and number of inhalations on aerosol-delivery of inhaled-salbutamol from two different dry powder inhalers (DPIs) in both healthy-subjects and chronic obstructive pulmonary disease (COPD) patients. Relative pulmonary-bioavailability and systemic-bioavailability of inhaled-salbutamol, delivered by Diskus and Aerolizer, was determined in 24-COPD patients and 24-healthy subjects. The healthy-subjects and the COPD-patients participated in the study for 7 days in which they received 4 study doses of 200 μg salbutamol (one slow-inhalation, two slow-inhalations, one fast-inhalation, and two fast-inhalations) in four alternative days with 24 hr washout period after each dose. Two urine-samples were collected from each study subjects. The first was provided 30 min post inhalation (USAL0.5), as an index of relative pulmonary-bioavailability, and the second was pooled to 24 hr post inhalation (USAL24), as an index of systemic-bioavailability. Fast-inhalation resulted in significantly higher USAL0.5 and USAL24 than slow-inhalation (p˂0.05) after one-inhalation in both healthy-subjects and COPD-patients but there was no significant difference between slow and fast-inhalation after two-inhalations. One-inhalation resulted in significantly higher USAL0.5 and USAL24 in healthy-subjects compared to COPD-patient at both slow and fast-inhalation (p˂0.05) except USAL0.5 with Diskus at slow-inhalation there was no significant difference. Also, two-inhalations resulted in significantly higher USAL0.5 and USAL24 compared to one-inhalation at slow-inhalation only (p˂0.05). No significant difference was found between Aerolizer and Diskus except in USAL0.5 of one slow-inhalation in both health-subjects and COPD-patients (p = 0.048 and 0.047, respectively). Device-formula relation is present at low inhalation-flow since Diskus resulted in significantly higher USAL0.5 and USAL24 in healthy-subjects compared to COPD-patient at slow inhalation than Aerolizer. It is essential to inhale-twice and as hard and deep as possible from each dose when using DPI especially with COPD-patients having poor inspiratory efforts such as elderly patients and children.

Computational fluid dynamics (CFD) modeling offers a powerful tool for the development of drug delivery devices using a first principles approach but has been underutilized in the development of pharmaceutical inhalers. The objective of this study was to develop quantitative correlations for predicting the aerosolization behavior of a newly proposed dry powder inhaler (DPI). The dose aerosolization and containment (DAC) unit DPI utilizes inlet and outlet air orifices designed to maximize the dispersion of spray-dried powders, typically with low air volumes (~ 10 mL) and relatively low airflow rates (~ 3 L/min). Five DAC unit geometries with varying orifice outlet sizes, configurations, and protrusion distances were considered. Aerosolization experiments were performed using cascade impaction to determine mean device emitted dose (ED) and mass median aerodynamic diameter (MMAD). Concurrent CFD simulations were conducted to predict both flow field-based and particle-based dispersion parameters that captured different measures of turbulence. Strong quantitative correlations were established between multiple measures of turbulence and the experimentally observed aerosolization metrics of ED and MMAD. As expected, increasing turbulence produced increased ED with best case values reaching 85% of loaded dose. Surprisingly, decreasing turbulence produced an advantageous decrease in MMAD with values as low as approximately 1.6 μm, which is in contrast with previous studies. In conclusion, CFD provided valuable insights into the performance of the DAC unit DPI as a new device including a two-stage aerosolization process offering multiple avenues for future enhancements.

Background: Predicting local lung tissue pharmacodynamic (PD) responses of inhaled drugs is a longstanding challenge related to the lack of experimental techniques to determine local free drug concentrations. This has prompted the use of physiologically based pharmacokinetic (PBPK) modeling to potentially predict local concentration and response. A unique opportunity for PBPK model evaluation is provided by the clinical PD data for salbutamol, which in its inhaled dosage form (400 μg), produces a higher bronchodilatory effect than in its oral dosage form (2 mg) despite lower drug concentrations in blood. The present study aimed at evaluating whether inhalation PBPK model predictions of free drug in tissue would be predictive of these observations., Methods: A PBPK model, including 24 airway generations, was parameterized to describe lung, plasma, and epithelial lining fluid concentrations of salbutamol administered intratracheally and intravenously to rats (100 nmol/kg). Plasma and lung tissue concentrations of unbound (R)-salbutamol, the active enantiomer, were predicted with a humanized version of the model and related to effect in terms of forced expiratory volume in 1 second (FEV 1 )., Results: In contrast to oral dosing, the model predicted inhalation to result in spatial heterogeneity in the target site concentrations (subepithelium) with higher free drug concentrations in the lung as compared with the plasma. FEV 1 of inhaled salbutamol was accurately predicted from the PK/PD relationship derived from oral salbutamol and PBPK predictions of free concentration in airway tissue of high resistance (e.g., 6th generation)., Conclusion: An inhalation PBPK-PD model was developed and shown predictive of local pharmacology of inhaled salbutamol, thus conceptually demonstrating the validity of PBPK model predictions of free drug concentrations in lung tissue. This achievement unlocks the power of inhalation PBPK modeling to interrogate local pharmacology and guide optimization and development of inhaled drugs and their formulations.

Objectives: The aim of the study was to investigate the pharmacokinetics and tolerability of salbutamol/ambroxol fixed-dose combination granules following single and multiple dosing in healthy Chinese subjects., Materials and Methods: This was a randomized, open-label, two-period, one-sequence study (n = 12). Each subject received a single oral dose in period 1 and multiple doses in period 2. Plasma concentrations of these two components were determined using a validated LC-MS/MS method. Adverse events (AEs) were documented throughout the study. Investigators evaluated AEs in terms of frequency, duration, intensity, seriousness, outcome, and relationship to study drugs., Results: Following single dosing, C max values were 8.07 ± 1.31 ng/mL and 25.7 ± 6.5 ng/mL for salbutamol and ambroxol, respectively. The corresponding T 1/2 values were 8.15 ± 3.13 hours and 9.31 ± 2.27 hours, respectively. Moreover, no statistical differences in the pharmacokinetics of salbutamol and ambroxol in subjects receiving single or multiple dosage were observed. Single- and multiple-dose oral administration of fixed-dose combination granules were safe and well tolerated in healthy Chinese subjects. Drug hypersensitivity syndrome did not occur during our study., Conclusion: The pharmacokinetics of salbutamol and ambroxol in the fixed-dose combination granules were not affected by dosing duration, and gender differences seemed to have no effect on the pharmacokinetics of salbutamol and ambroxol after a single dose and multiple doses of the medication.
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Background: The aim of this work was to determine the effect of fill volume and humidification change on aerosol delivery during single-limb noninvasive ventilation (NIV)., Methods: Four groups were recruited, each consisting of 12 subjects (6 females) with COPD receiving NIV. Groups 1 and 3 received inhaled salbutamol with a vibrating mesh nebulizer, and Groups 2 and 4 received inhaled salbutamol with a jet nebulizer. The in vivo study was carried out on days 1 and 3. In groups 1 and 2, 2 fill-volumes were delivered to each subject; 1 mL 5,000 μg/mL salbutamol respirable solution used as it is or diluted to a total of 2 mL using normal saline. In groups 3 and 4, 1 mL 5,000 μg/mL salbutamol respirable solution diluted to 2 mL total volume using normal saline was delivered to each subject with and without humidification. Unchanged salbutamol in urine at 30 min (USAL0.5) and in pooled urine at 24 h (USAL24) was determined. On day 2, the ex vivo study was carried out on subjects using the same experimental setting with a filter placed proximal to their face mask for collection of total inhaled dose of salbutamol (aerosol emitted)., Results: The vibrating mesh nebulizer delivered higher USAL0.5, USAL24, and aerosol emitted compared to the jet nebulizer at all fill volumes and humidification conditions ( P < .001). Increasing fill volume from 1 mL to 2 mL resulted in a significant increase in USAL0.5, USAL24, and aerosol emitted from the jet nebulizer ( P < .05) with an insignificant effect on the vibrating mesh nebulizer. A 2-mL fill volume with the jet nebulizer delivered USAL24 and aerosol emitted comparable to those of 1 mL with the vibrating mesh nebulizer with significantly longer nebulization times ( P < .001). Humidification had an insignificant effect on aerosol delivery., Conclusions: Increasing the fill volume of a jet nebulizer is essential to increase the amount of inhaled medication reaching a subject. In contrast, there is no need to increase fill volumes when using a vibrating mesh nebulizer. There is no need to switch off the humidifier while delivering aerosol through a single-limb NIV circuit., (Copyright © 2018 by Daedalus Enterprises.)

Background: Predosing patients with COPD with salbutamol by using a pressurized metered-dose-inhaler (pMDI) as a bronchodilator was hypothesized to improve the distribution of the subsequent nebulized dose. This study determined the effect of a pMDI preliminary bronchodilator dose on the aerosol delivered by a mesh nebulizer during single-limb noninvasive ventilation., Methods: Twelve subjects with COPD who received noninvasive ventilation were enrolled in a randomized, open-label, urinary pharmacokinetic study. A bi-level ventilator with a dry single-limb circuit and the fixed expiratory port was set in the spontaneous mode, with initial inspiratory and expiratory pressures of 20 and 5 cm H 2 O respectively, a 1:3 inspiratory-expiratory ratio, and 15 breaths/min. Salbutamol was administered via a mesh nebulizer with a large spacer or T-piece placed between the fixed-orifice expiratory valve and the oronasal mask. In vivo dosing methods were randomized for days 1, 3, and 5 of the study. On each day, a 1-mL respirable solution that contained 5,000 μg salbutamol was nebulized by using a mesh nebulizer with 3 setting: (1) T-piece, (2) large spacer, and (3) large spacer plus pMDI. Only with the large spacer plus pMDI setting, 2 pMDI doses, which contained 100 μg salbutamol each, were actuated before nebulization. Urine samples were collected at 0.5 h (as an index of pulmonary bioavailability) and pooled up to 24 h after dosing (as an index of systemic absorption). On day 2, ex vivo studies were performed for the 3 setting with salbutamol collected onto filters placed before the mask. The drug was eluted from the filters and analyzed to determine the inhaled dose., Results: A large spacer plus pMDI showed a trend to deliver a higher fraction (percentage of nominal dose) of both ex vivo filters and 0.5-h urinary salbutamol. The 0.5-h urinary salbutamol excreted with a large spacer plus pMDI (1.99%) was larger than with the T-piece (1.73%) and large spacer (1.78%). This trend did not extend to the 24-h levels, in which bioavailability with the large spacer plus pMDI (49.9%) was lower than with the T-piece (52.8%) and with the large spacer (54.3%). However, no differences were significant., Conclusions: The T-piece and large spacer were equally efficient for salbutamol delivery from the mesh nebulizer in patients with COPD and on single-limb noninvasive ventilation. Adding a preliminary bronchodilator dose by pMDI prenebulization showed a trend toward greater pulmonary bioavailability of nebulized salbutamol and may be worth considering to maximize delivery of salbutamol to patients who are severely ill., (Copyright © 2018 by Daedalus Enterprises.)

Aims: Salbutamol is used in the management of obstructive bronchospasm, including that of some elite athletes. It is claimed that high salbutamol (oral) doses may also have an anabolic effect. Therefore, inhalation of salbutamol is restricted by the World Anti-Doping Agency (WADA) to a maximal daily dose. Urine is tested for violations, but recent cases have resulted in a debate regarding the validity of this approach. It was our aim to determine whether current approaches are sufficiently able to differentiate approved usage from violations., Methods: We extracted pharmacokinetic parameters from literature for salbutamol and its sulphated metabolite. From these parameters, a semi-physiological pharmacokinetic model of inhaled and orally administered salbutamol was synthesized, validated against literature data, and used to perform clinical trial simulations (n = 1000) of possible urine concentrations over time resulting from WADA-allowed and oral unacceptable dosages., Results: The synthesized model was able to predict the literature data well. Simulations showed a very large range of salbutamol concentrations, with a significant portion of virtual subjects (15.4%) exceeding the WADA threshold limit of 1000 ng ml -1 at 1 h post-dose., Conclusions: The observed large variability in urine concentrations indicates that determining the administered dose from a single untimed urine sample is not feasible. The current threshold inadvertently leads to incorrect assumptions of violation, whereas many violations will go unnoticed, especially when samples are taken long after drug administration. These issues, combined with the dubious assertion of its anabolic effect, leads us to conclude that the large effort involved in testing should be reconsidered., (© 2018 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Background: Emergency department (ED) treatment of hyperkalemia often involves shifting potassium into the intracellular space. There is uncertainty whether transcellular shifting causes insufficient potassium removal during hemodialysis, resulting in a subsequent need for further medical therapy or multiple sessions of hemodialysis., Objective: We sought to determine whether transcellular potassium shifting in ED patients with hyperkalemia who undergo hemodialysis is associated with recurrent hyperkalemia with or without repeat hemodialysis within 24 h., Methods: This was a retrospective observational study of ED patients with a potassium value > 5.3 mmol/L and ≥1 hemodialysis run. Transcellular shifting medications were defined as albuterol, insulin, and sodium bicarbonate. Primary outcomes were recurrent hyperkalemia with and without repeat hemodialysis within 24 h of the initial dialysis run. Generalized estimating equation models were created for the outcomes using administration of a shifting medication as the primary predictor., Results: Four hundred seventy-nine encounters were identified. In 238 (50%) encounters, a shifting medication was administered. There were 85 outcomes of recurrent hyperkalemia and 36 outcomes of recurrent hyperkalemia with repeat hemodialysis. After adjustment, administration of shifting medications was not associated with recurrent hyperkalemia (adjusted odds ratio 1.26, 95% confidence interval 0.71-2.23) or recurrent hyperkalemia with repeat dialysis (adjusted odds ratio 1.90, 95% confidence interval 0.80-4.48)., Conclusions: Administration of transcellular shifting medications for hyperkalemia in the ED was not associated with either recurrent hyperkalemia after hemodialysis or the need for a second dialysis session within 24 h. Our findings address the uncertainty regarding transcellular potassium shifting before emergent dialysis and support safe ED administration of medications that shift potassium to the intracellular space., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objectives: The aims of the study were to investigate the potential drug-drug interaction between salbutamol and ambroxol, the bioequivalence of the new fixed-dose combination containing salbutamol and ambroxol compared with co-administration of the two separate formulations, and to describe the safety and tolerability of the fixed-dose combination formulation in healthy Chinese volunteers., Materials and Methods: An open-label, single-dose, four-treatment, four-period crossover study for evaluation of drug-drug interaction and bioequivalence (n = 24) was performed. Each participant received salbutamol 4 mg, ambroxol 15 mg, salbutamol 4 mg co-administered with ambroxol 15 mg or fixed-dose combination formulation (salbutamol 4 mg and ambroxol 15 mg). Plasma concentrations of two analytes were determined with the use of validated LC-MS/MS method. Safety and tolerability were assessed by recording adverse events., Results: Co-administration of salbutamol and ambroxol was not associated with a significant influence on single salbutamol or ambroxol pharmacokinetics. After statistical comparisons of log-transformed C max and AUC of salbutamol and ambroxol between fixed-dose combination and concomitant treatments, all 90% confidence intervals of geometric mean ratios were within the predefined equivalence range of 80 - 125%. No serious adverse events were reported, and all treatments were safe and well tolerated in Chinese healthy subjects., Conclusion: There were no significant drug-drug pharmacokinetic interactions between salbutamol and ambroxol after oral administration. The new formulation was bioequivalent to the co-administration of two drugs in separate dosage forms.
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Background: Placement of a heat moisture exchanger (HME) between aerosol generator and patient has been associated with greatly reduced drug delivery. The purpose of this study was to evaluate the effect of filtered and nonfiltered HMEs placed between nebulizer and patient on aerosol deposition and airway resistance (Raw) in simulated ventilator-dependent adults., Methods: An in vitro lung model was developed to simulate a mechanically ventilated adult (Vt 500 mL, RR 15/min, and PEEP 5 cmH 2 O, using two inspiratory flow rates 40 and 50 L/min) using an intubated adult manikin with an endotracheal tube (8 mmID). The bronchi of the manikin were connected to a Y-adapter through a collecting filter (Respirgard II) attached to a test lung through a heated humidifier (37°C producing 100% relative humidity) to simulate exhaled humidity. For treatment conditions, a nonfiltered HME (ThermoFlo™ 6070; ARC Medical) and filtered HMEs (ThermoFlo™ Filter; ARC Medical and PALL Ultipor; Pall Medical) were placed between the ventilator circuit at the endotracheal tube and allowed to acclimate to the exhaled heat and humidity for 30 minutes before aerosol administration. Airway resistance (cmH 2 O/L/s) was taken at 0, 10, 20, and 30 minutes after HME placement and after each of four aerosol treatments. Albuterol sulfate (2.5 mg/3 mL) was administered with jet (Misty Max 10; Airlife) and mesh (Aerogen Solo; Aerogen) nebulizers positioned in the inspiratory limb proximal to the Y-adapter. Control consisted of nebulization with no HME. Drug was eluted from filter at the end of the trachea and measured using spectrophotometry (276 nm)., Results: Greater than 60% of the control dose was delivered through the ThermoFlo. No significant difference was found between the first four treatments given by the jet (p = 0.825) and the mesh (p = 0.753) nebulizers. There is a small increase in Raw between pre- and post-four treatments with the jet (p = 0.001) and mesh (p = 0.015) nebulizers. Aerosol delivery through filtered HMEs was similar (<0.5%) across the four treatments. Airway resistance was similar using the ThermoFlo Filter. With the PALL Ultipor, changes in Raw increased with mesh nebulizer after treatment (p = 0.005). Changes in resistance pre- and post-treatment were similar with both filtered HMEs., Conclusion: The ThermoFlo™ nonfilter HME allowed the majority of the control dose to be delivered to the airway. Increases in Raw would likely not be outside of a tolerable range in ventilated patients. In contrast, filtered HMEs should not be placed between nebulizers and patient airways. Further research with other HMEs and materials is warranted.

In order to monitor salbutamol (SAL) use in goats as a repartitioning, we determined SAL residues in various tissues of goats after repeated oral SAL administration at a dose of 0.15 mg/kg daily for 21 days. SAL concentrations were measured by ultra performance liquid chromatography tandem mass spectrometry in extracts of tissues from goats sacrificed 0.25, 1, 3, 7, 14, 21 and 28 days after the last dose. Our results showed that on Day 0.25 of the withdrawal period, the residual proportions of SAL (expressed as percentage) in liver, kidney, lung, hair, stomachs and muscle were 19.5%, 15.3%, 3.3%, 9.6%, 28.2% and 0.8%, respectively. As the withdrawal time increased, the SAL concentrations in most tissues (except hair) decreased rapidly over the first 3 days and more slowly in the following 25 days. After a 28-day withdrawal period, hair, lung, muscle, liver, fat, eyes, rumen, kidney and abomasum still contained ~32.3%, 15.3%, 7.1%, 6.5%, 5.6%, 1.5%, 0.8% and 0.5% compared to the initial residual concentrations determined on Day 0.25, respectively. On withdrawal Day 28, the highest concentrations of SAL were found in hair (16.58 ± 9.48 μg/kg), followed by liver (7.01 ± 0.94 μg/kg), lung (2.81 ± 1.23 μg/kg), kidney (0.64 ± 0.56 μg/kg), whereas the concentrations in other tissues were lower than limit of quantification (0.50 μg/kg). SAL residues were not detected in bile, plasma and brain on Days 7, 7 and 3 after discontinuation of dosing. These findings indicated that the distribution and depletion rates of SAL differed between tissues. It should be noted that SAL residues in stomach were higher than those in muscles during the early withdrawal. We conclude that hair is the preferred tissue to monitor the administration of SAL to living goats, whereas liver can be used to monitor SAL in the carcass for determination of compliance with food safety regulation.

Background: During mechanical ventilation medical aerosol delivery has been reported to be upto two fold greater with dry inhaled gas than with heated humidity. Urine levels at 0.5 h post dose (URSAL0.5%) has been confirmed as an index of lung deposition and 24 h (URSAL24%) as index of systemic absorption. Our aim was to determine the effect of humidification and aerosol device type on drug delivery to ventilated patients using urine levels., Methods: In a randomized crossover design, 36 (18female) mechanically ventilated patients were assigned to one of three groups. Groups 1 and 2 received 5000 μg salbutamol using vibrating mesh (VM) and jet nebulizers (JN), respectively, while group 3 received 1600 μg (16 puffs) of salbutamol via metered dose inhaler with AeroChamber Vent (MDI-AV). All devices were placed in the inspiratory limb of ventilator downstream from the humidifier. Each subject received aerosol with and without humidity at >24 h intervals with >12 h washout periods between salbutamol doses. Patients voided urine 15 min before each study dose and urine samples were collected at 0.5 h post dosing and pooled for the next 24 h., Results: The MDI-AV and VM resulted in a higher percentage of urinary salbutamol levels compared to the JN (p < 0.05). Urine levels were similar between humidity and dry conditions., Conclusions: Our findings suggest that in-vitro reports overestimate the impact of dry vs. heated humidified conditions on the delivery of aerosol during invasive mechanical ventilation., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: A key issue in pulmonary drug delivery is improvement of the delivery device for effective and targeted treatment. Pressurized metered dose inhalers (pMDIs) are the most popular aerosol therapy device for treating lung diseases. This article studies the effect of spray characteristics: injection velocity, spray cone angle, particle size distribution (PSD), and its mass median aerodynamic diameter (MMAD) on drug delivery., Methods: An idealized oral airway geometry, extending from mouth to the main bronchus, was connected to a pMDI device. Inhalation flow rates of 15, 30, and 60 L/min were used and drug particle tracking was a one-way coupled Lagrangian model., Results: The results showed that most particles deposited in the pharynx, where the airway has a reduced cross-sectional area. Particle deposition generally decreased with initial spray velocity and with increased spray cone angle for 30 and 60 L/min flow rates. However, for 15 L/min flow rate, the deposition increased slightly with an increase in the spray velocity and cone angle. The effect of spray cone angle was more significant than the initial spray velocity on particle deposition. When the MMAD of a PSD was reduced, the deposition efficiency also reduces, suggesting greater rates of particle entry into the lung. The deposition rate showed negligible change when the MMAD was more than 8 μm., Conclusion: Spray injection angle and velocity change the drug delivery efficacy; however, the efficiency shows more sensitivity to the injection angle. The 30 L/min airflow rate delivers spray particles to the lung more efficiently than 15 and 60 L/min airflow rate, and reducing MMAD can help increase drug delivery to the lung.

Background: The effectiveness of metered-dose inhalers (MDIs) in delivering medication to the lungs highly depends on its correct usage technique. Current guidelines state optimal technique for high lung deposition should include a slow inhalation (>5 seconds) at an inspiratory flow rate of 30 L/min and inhaler actuation at the start of inhalation. However, these recommendations were based on clinical studies using CFC (chlorofluorocarbon)-MDIs and in vitro studies of HFA (hydrofluoroalkane)-MDIs using idealized MDI techniques of uniform inhalation and actuation, disregarding the nonuniform techniques of actual patients., Methods: To better understand the effects of time-varying MDI usage parameters on lung deposition of aerosol delivered by an HFA-MDI, we conducted an in vitro study modeled on real-life variable inspiratory flow and actuation techniques recorded from 15 subjects with asthma/chronic obstructive pulmonary disease (COPD). We developed a model representing the time-varying inspiratory flow waveforms and actuation timings based on 43 MDI techniques recorded from patients. Furthermore, we constructed an in vitro experimental setup using a mouth-throat cast, programmable MDI actuator, and breath simulator to evaluate lung deposition for the MDI techniques derived from our model., Results: High inspiratory flow rates, 60-90 L/min, consistently resulted in high in vitro lung deposition (>40%) of aerosol (albuterol delivered from Ventolin HFA-MDI) compared to 30 L/min when MDI actuation occurred in the first half of inhalation. Also, positive coordination resulted in higher in vitro lung deposition compared with negative or zero coordination (actuating before or at the start of inspiration). Furthermore, variation in coordination affected lung deposition more significantly (23%) than flow rate or duration of inspiration (≤5%)., Conclusions: In an in vitro experimental model based on inhalation data from patients with asthma and COPD, we demonstrated that aerosol lung deposition emitted from Ventolin HFA-MDI is most optimal for MDI actuation in the first half of inspiration at high flow rates (60-90 L/min).

Background: Researchers, using checklists, have identified that 30%-90% of patients make errors in inhaler use. It is not certain whether these errors affect the delivery of medication. We have developed an electronic monitor (INCA™) that records audio each time an inhaler is used, providing objective information on inhaler technique. The aim of this study was to assess the effect that correctly identified inhaler errors, with the INCA device, have on drug delivery., Methods: This was a prospective study of healthy volunteers using a salbutamol Diskus™. The inclusion criteria allowed for the recruitment of healthy participants who were nonfrequent users of Salbutamol. Each participant was assigned to one control "phase" first and two/three subsequent error "phases." Each phase consisted of six doses of the drug taken 6 hours apart, and the participants' blood was drawn before and 25 minutes after doses one and six. This allowed us to sample their trough and peak serum salbutamol levels., Results: Fourteen healthy volunteers were studied. The inhaler technique errors simulated in this study included exhaling into the device after drug priming but before inhalation, low inspiratory flow, multiple inhalations, low breath hold, missed doses, and wrong inhaler position. Only the exhalation error, low inspiratory flow, and missed doses led to a significant reduction in serum salbutamol levels. After six doses of the exhalation error, there was a 62% reduction in peak salbutamol levels. Low inspiratory flow led to a 52% reduction in peak salbutamol levels and a 78% reduction in trough levels. Missed doses led to a 37% reduction in trough salbutamol levels., Conclusions: These findings confirm that technique errors affect drug delivery. Furthermore, we were able to identify that the most critical technique errors with the Diskus inhaler are exhalation into the device before inhalation, poor inspiratory flow, and missing doses.

Aims: Salbutamol is usually administered as a racemic mixture but little is known about the enantioselectivity of salbutamol pharmacokinetics in the lung. This study was designed to investigate enantiomer concentrations in lung tissue after inhaled dosing., Methods: Horses (n = 12) received racemic salbutamol 1000 μg via inhalation. Enantioselective ultra performance liquid chromatography-tandem mass spectrometry was used to determine salbutamol concentrations in pulmonary epithelial lining fluid (PELF) sampled 2, 5, 10 and 15 min after administration, in central lung (endoscopic bronchial biopsy) and peripheral lung (percutaneous pulmonary biopsy) tissues (at 20 and 25 min respectively), and in plasma samples., Results: Mean ± 95% confidence interval (CI) yield of PELF was 57 ± 10 mg. Initial mean ± 95%CI (R)- and (S)-salbutamol PELF concentrations were 389 ± 189 ng g -1 and 378 ± 177 ng g -1 respectively, and both reduced approximately 50% by 15 min. Mean ± 95%CI central lung levels of drug were higher than peripheral lung tissue for both (R)-salbutamol (875 ± 945 vs. 49.5 ± 12 ng g -1 ) and (S)-salbutamol (877 ± 955 vs. 50.9 ± 12 ng g -1 ) respectively. There was no evidence of enantioselectivity in PELF or central lung but minor (~2%) enantioselectivity was observed in the peripheral lung. Enantioselectivity was clearly evident in plasma with (S):(R) ratio of 1.25 and 1.14 for both area under the concentration-time curve (0-25 min) and C max respectively., Conclusions: PELF sampling in horses offers sufficient yield allowing direct detection of drug and, combined with tissue sampling, is a valuable model to investigate bronchopulmonary pharmacokinetics. Salbutamol did not demonstrate enantioselectivity in PELF or central lung tissue uptake following acute dosing, however, enantioselective plasma concentrations were demonstrated, with minor enantioselectivity in the peripheral lung., (© 2017 The British Pharmacological Society.)

Aim: To compare the systemic exposure of salbutamol following delivery from the unit dose dry powder inhaler (UD-DPI) system with that from the Diskus ® and metered dose inhaler (MDI)., Materials and Methods: This open-label, two-part, six-way crossover, randomized single-dose study in healthy subjects evaluated salbutamol systemic exposure of three dose strengths (using three inhalations: 3 × 150 μg [450 μg], 3 × 200 μg [600 μg], and 3 × 250 μg [750 μg]) and 2% of drug in lactose blends (1.6% and 1.0% [600 μg dose only] by weight) following delivery through the UD-DPI compared with systemic exposure from the Diskus and MDI (600 μg dose). Systemic exposure in the presence of charcoal block was also evaluated. Primary treatment comparisons were area under the concentration-time curve from time zero to 12 hours [AUC 0-12 ] and maximum plasma concentration [C max ]., Results: Delivery of salbutamol 600 μg from the UD-DPI resulted in total systemic exposure similar to that from the Diskus and approximately half of that from the MDI (AUC 0-12 geometric least squares mean ratio [GMR] [90% confidence interval (CI)] for UD-DPI [1.6% blend]/Diskus: 0.91 [0.83-1.00]; UD-DPI [1.6% blend]/MDI: 0.46 [0.42-0.50]. C max GMR [90% CI] for UD-DPI [1.6% blend]/Diskus: 1.20 [1.07-1.33]; UD-DPI [1.6% blend]/MDI: 0.58 [0.52-0.64]). Results were consistent between the 1.6% and the 1.0% blends and systemic exposure for the 3 dose strengths of salbutamol (1.6% blend) showed increases that were 12-16% greater than dose proportional. Systemic exposure due to pulmonary absorption (as calculated from AUC 0-12 in the presence and absence of charcoal block) was 48% for the UD-DPI, 24% for Diskus, and 37% for MDI of the total salbutamol systemic exposure, and the corresponding estimated lung dose was 65% for the UD-DPI and 34% for the Diskus relative to the MDI., Conclusions: Salbutamol total systemic exposure following UD-DPI was similar to that from the Diskus and was lower than that following the MDI. The different blend formulations tested resulted in consistent salbutamol systemic exposure. The contribution of the lung and gut to systemic exposure revealed a different profile for the three inhaler platforms. These data suggest that the UD-DPI warrants further evaluation.

This study analysed the relaxant properties of salbutamol (β2-adrenoceptors agonist) and BRL 37344 (β3-adrenoceptors agonist) regarding the contractility of porcine myometrium on days 10-14 of the oestrous cycle (cyclic group; n = 10) and on days 3-5 of pregnancy (early pregnant group; n = 6). The activity of myometrial strips (tension, frequency and amplitude) was recorded under isometric conditions using force transducers. The contractility was assessed further following the administration of increasing concentrations of the agonists (10-9-10-4 M), both with and without β-adrenoceptor antagonists (butaxamine - a selective β2- adrenoceptor antagonist, propranolol- a non-selective β1- and β2-adrenoceptor antagonist and bupranolol - a non-selective β1-, β2- and β3-adrenoceptor antagonist) at a concentration of 10-4 M. Although neither salbutamol nor BRL 37344 caused changes in the tension, at the highest concentrations they decreased the frequency and amplitude of contractions. These changes were more evident after salbutamol treatment and in the early pregnant group. Antagonists given alone did not cause changes in the parameters examined but changed some activity of the agonists. Butoxamine reduced the decrease in frequency and amplitude induced by salbutamol and produced a decrease in the tension after BRL 37344 treatment in the early pregnant group. Propranolol reduced the decrease in frequency and amplitude induced by salbutamol in both examined groups and did not cause significant changes in BRL 37344 activity. The administration of bupranolol before salbutamol treatment caused an increase in the tension and reduced the decrease in the frequency in the cyclic group. Moreover, bupranolol eliminated a decrease in frequency and induced an increase in amplitude caused by BRL 37344 in both groups and these changes were more evident in the early pregnant group. The data indicates that both β2- and β3-adenoreceptors are involved in the regulation of the contractility in both groups, but the changes after agonists and antagonists treatment are more evident in the early pregnant myometrium.

Background: The ability to provide safe and effective pharmacotherapy during obstetric complications, such as preterm labor or postpartum hemorrhage, is hampered by the systemic toxicity of therapeutic agents leading to adverse side effects in the mother and fetus. Development of novel strategies to target tocolytic and uterotonic agents specifically to uterine myocytes would improve therapeutic efficacy while minimizing the risk of side effects. Ligand-targeted liposomes have emerged as a reliable and versatile platform for targeted drug delivery to specific cell types, tissues or organs., Objective: Our objective was to develop a targeted drug delivery system for the uterus utilizing an immunoliposome platform targeting the oxytocin receptor., Study Design: We conjugated liposomes to an antibody that recognizes an extracellular domain of the oxytocin receptor. We then examined the ability of oxytocin receptor-targeted liposomes to deliver contraction-blocking (nifedipine, salbutamol and rolipram) or contraction-enhancing (dofetilide) agents to strips of spontaneously contracting myometrial tissue in vitro (human and mouse). We evaluated the ability of oxytocin receptor-targeted liposomes to localize to uterine tissue in vivo, and assessed if targeted liposomes loaded with indomethacin were capable of preventing lipopolysaccharide-induced preterm birth in mice., Results: Oxytocin receptor-targeted liposomes loaded with nifedipine, salbutamol or rolipram consistently abolished human myometrial contractions in vitro, while oxytocin receptor-targeted liposomes loaded with dofetilide increased contraction duration. Nontargeted control liposomes loaded with these agents had no effect. Similar results were observed in mouse uterine strips. Following in vivo administration to pregnant mice, oxytocin receptor-targeted liposomes localized specifically to the uterine horns and mammary tissue. Targeting increased localization to the uterus 7-fold. Localization was not detected in the maternal brain or fetus. Targeted and nontargeted liposomes also localized to the liver. Oxytocin receptor-targeted liposomes loaded with indomethacin were effective in reducing rates of preterm birth in mice, whereas nontargeted liposomes loaded with indomethacin had no effect., Conclusion: Our results demonstrate that oxytocin receptor-targeted liposomes can be used to either inhibit or enhance human uterine contractions in vitro. In vivo, the liposomes localized to the uterine tissue of pregnant mice and were effective in delivering agents for the prevention of inflammation-induced preterm labor. The potential clinical advantage of targeted liposomal drug delivery to the myometrium is reduced dose and reduced toxicity to both mother and fetus., (Copyright © 2016. Published by Elsevier Inc.)

Inhaled budesonide and salbutamol represent the most important and frequently used drugs in asthmatic children during acute exacerbation. However, there is still no consensus about their resulting metabolic derangements; thus, this study was conducted to determine the distinct metabolic profiles of these two drugs. A total of 69 children with asthma during acute exacerbation were included, and their serum and urine were investigated using high-resolution nuclear magnetic resonance (NMR). A metabolomics analysis was performed using a principal component analysis and orthogonal signal correction-partial least squares using SIMCA-P. The different metabolites were identified, and the distinct metabolic profiles were analysed using MetPA. A high-resolution NMR-based serum and urine metabolomics approach was established to study the overall metabolic changes after inhaled budesonide and salbutamol in asthmatic children during acute exacerbation. The perturbed metabolites included 22 different metabolites in the serum and 21 metabolites in the urine. Based on an integrated analysis, the changed metabolites included the following: increased 4-hydroxybutyrate, lactate, cis-aconitate, 5-hydroxyindoleacetate, taurine, trans-4-hydroxy-l-proline, tiglylglycine, 3-hydroxybutyrate, 3-methylhistidine, glucose, cis-aconitate, 2-deoxyinosine and 2-aminoadipate; and decreased alanine, glycerol, arginine, glycylproline, 2-hydroxy-3-methylvalerate, creatine, citrulline, glutamate, asparagine, 2-hydroxyvalerate, citrate, homoserine, histamine, sn-glycero-3-phosphocholine, sarcosine, ornithine, creatinine, glycine, isoleucine and trimethylamine N-oxide. The MetPA analysis revealed seven involved metabolic pathways: arginine and proline metabolism; taurine and hypotaurine metabolism; glycine, serine and threonine metabolism; glyoxylate and dicarboxylate metabolism; methane metabolism; citrate cycle; and pyruvate metabolism. The perturbed metabolic profiles suggest potential metabolic reprogramming associated with a combination treatment of inhaled budesonide and salbutamol in asthmatic children., (© 2016 The Authors. Basic & Clinical Pharmacology & Toxicology published by John Wiley & Sons Ltd on behalf of Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).)

Substituting nebulisers by another in non-invasive ventilation circuit (NIV) involves many process variables which must be adjusted to ensure patient optimum therapy. However, there is a doubt when nebulisers use the same technology. Data mining technology based on artificial neural networks and genetic algorithms were used here to model in-vitro inhalation process and predict bioavailability from inhaled doses delivered by three different vibrating mesh nebulisers (VMNs) in NIV. Modelling of data indicated that in-vitro performance of VMNs was dependent mainly on fine particle fraction, mass median aerodynamic diameter (MMAD), total emitted dose (TED) and to lesser extent on nebuliser type. Ex-vivo model indicated that amount of salbutamol collected on facemask filter was directly affected by TED. In-vivo model showed that amount of salbutamol deposited into the lung (0.5hQ) and amount absorbed systemically (24hQ) were dependent directly on MMAD and TED. Female patients showed higher 24hQ values than males. Nebuliser type affected TED, 0.5hQ but not 24hQ values. Results indicate suitability of VMNs in achieving appropriate in-vitro inhalation performance model. The results also, indicate that the three VMNs are comparable and can be interchanged with no fear of any additional toxicity., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Background: Salbutamol sulphate (SS) is a model short-acting β2-adrenergic receptor agonist used for the relief of bronchospasm having poor bioavailability (50%) due to its extensive first-pass effect., Objective: Formulation of SS as fast dissolving sublingual films (FDSFs) using a biocompatible and biodegradable Pullulan polymer to bypass its metabolism in liver and offers a fast relieve of asthma., Method: Films were prepared by solvent casting technique adopting 32 factorial design to study the effect of two independent variables namely; polymer type (HPMC E5, Pullulan, and L-HPC) and polymer to Maltodextrin ratio (3:0, 3:1 or 5:1). Films physicomechanical properties, disintegration time and in-vitro dissolution of the prepared formulations were evaluated., Results: Formula F3 containing Pullulan with Maltodextrin in a ratio 3:1 has the least disintegration time (26±2.6 seconds) and the highest dissolution rate (100%±0.5%) after four minutes. Pharmacokinetic study of the optimum formula F3 in healthy human volunteers revealed a shorter tmax (0.75±0.25 hour) compared to Ventolin® tablet 2 mg (2.1±0.37 hour). Clinical evaluation of F3 in 14 male asthmatic patients using ZAN Spirometry showed clinical improvement in lung function parameters when compared with Ventolin® tablets., Conclusion: FDSFs significantly improved the bioavailability of SS and resulted in dramatic improvement in its clinical efficacy., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

In silico modeling was used to predict the impact of carrier surface modifications on the in vivo plasma concentration of an active pharmaceutical ingredient (API) and as a tool to support formulation development. In vitro fine particle fraction (FPF) and mass median aerodynamic diameter (MMAD) of salbutamol sulphate delivered from Cyclocaps ® , detached from unmodified and surface engineered glass beads were measured using a Next Generation Impactor (NGI). Surface roughness was chosen to classify surface modification/engineering and it was evaluated via scanning electron microscopy (SEM) and image analysis. An in silico pharmacokinetic (PK) model was built and the quality confirmed with available literature data. Plasma profiles were generated combining the PK model with in silico deposition models for salbutamol sulphate released from Cyclocaps ® , unmodified and surface engineered glass beads. The increased roughness of the surface of engineered beads resulted in a FPF 1.36 times higher than that of untreated beads. C max from the in silico plasma profile of salbutamol released from the surface engineered beads was 1.20 fold higher than that from untreated beads. Increasing the surface roughness was found to augment the amount of drug loading and detaching from the carrier both in vitro and in silico., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Albumin-based nanoparticles (NPs) are a promising technology for developing drug-carrier systems, with improved deposition and retention profiles in lungs. Improved understanding of these drug-carrier interactions could lead to better drug-delivery systems. The present study combines computational and experimental methods to gain insights into the mechanism of binding of albuterol sulfate (AS) to bovine serum albumin (BSA) on the molecular level. Molecular dynamics simulation and surface plasmon resonance spectroscopy were used to determine that there are two binding sites on BSA for AS: the first of which is a high-affinity site corresponding to AS1 and the second of which appears to represent the integrated functions of several low-affinity sites corresponding to AS2, AS3, and AS8. AS1 was the strongest binding site, established via electrostatic interaction with Glu243 and Asp255 residues in a hydrophobic pocket. Hydrogen bonds and salt bridges played a main role in the critical binding of AS1 to BSA, and water bridges served a supporting role. Based upon the interaction mechanism, BSA NPs loaded with AS were prepared, and their drug-loading efficiency, morphology, and -release profiles were evaluated. Successful clinical development of AS-BSA-NPs may improve therapy and prevention of bronchospasm in patients with reversible obstructive airway disease, and thus provide a solid basis for expanding the role of NPs in the design of new drug-delivery systems.

Background: Many children struggle with the use of albuterol hydrofluoroalkane (HFA) inhalers. Albuterol multidose dry powder inhaler (MDPI) may simplify rescue bronchodilator use in children., Objective: To compare the pharmacokinetics (PK), pharmacodynamics (PD), and tolerability of albuterol MDPI and albuterol HFA after a single inhaled dose in children with asthma., Methods: This single-center, open-label, two-period crossover study randomized children to albuterol MDPI or HFA 180 μg on two treatment days with a 4- to 14-day washout. Plasma albuterol concentrations were measured before the dose and up to 10 hours after the dose to determine the primary PK values of area under the plasma concentration-versus-time curve from time 0 to the last measurable concentration (AUC0-t), maximum observed concentration (Cmax), and AUC from time 0 extrapolated to infinity (AUC0-inf). Heart rate and blood pressure before the dose and after the dose were monitored for PD effects, and adverse events (AE) were monitored for overall safety., Results: Fifteen children, ages 6-11 years, were included (PK, n = 13 for time to Cmax and terminal half-life of elimination; n = 12 for AUC and Cmax due to incomplete data). AUC0-t (geometric mean ratio [GMR] 1.056 [90% confidence interval {CI}, 0.88-1.268]) and AUC0-inf (GMR 0.971 [90% CI, 0.821-1.147]) were comparable between treatments. Cmax was larger for albuterol MDPI versus HFA (GMR 1.340 [90% CI, 1.098-1.636]). PD parameters between the treatments were comparable. No deaths, serious AEs, treatment-emergent AEs, or withdrawals due to AEs were reported for either treatment., Conclusion: Albuterol MDPI and albuterol HFA had comparable PK and PD in children after a single 180-μg dose. ClinicalTrails.gov identifiers NCT01899144 and NCT02126839.

Context: Salbutamol is a short-acting β2-adrenergic receptor agonist that has been used for many years for relief of bronchospasm. However, studies on the pharmacokinetic profile of orally inhaled salbutamol doses used in clinical practice have not yet been reported in Chinese subjects., Objective: The aim of this study was to compare the pharmacokinetics and evaluate the bioequivalence of two orally inhaled salbutamol formulations., Materials and Methods: A single-dose randomized fasting two-period, two-treatment and two-sequence crossover open-label bioequivalence study was conducted in 24 healthy Chinese adult male volunteers, with a 1-week washout period between treatments. Plasma concentrations of salbutamol were determined using liquid chromatography coupled to tandem mass spectrometry. Pharmacokinetic parameters, including AUC0-0.33 h, AUC0-24 h and Cmax were calculated and the 90% confidence intervals of the ratio (test/reference) pharmacokinetic parameters were obtained by analysis of variance on logarithmically transformed data., Results: The mean (SD) pharmacokinetic parameters of the reference drug were AUC0-0.33 h, 227.2 (89.9) pg·h/ml; AUC0-24 h, 2551.9 (1008.0) pg·h/ml; Cmax, 801.3 (307.3) pg/ml and t1/2, 5.14(1.36) h. Those of the test drug were AUC0-0.33 h, 244.0 (104.4) pg·h/ml; AUC0-24 h, 2664.4 (1081.8) pg·h/ml; Cmax, 873.7 (374.4) pg/ml, t1/2, 5.29 (1.23) h. The median value for Tmax was 0.25 h for both formulations. The 90% confidence intervals for the AUC0-0.33 h, AUC0-24 h and Cmax were in the range of 0.892-1.208, 0.876-1.195 and 0.911-1.203, respectively., Conclusion: This single-dose study found that the test and reference products met the regulatory criteria for bioequivalence of China in healthy Chinese volunteers.

Introduction: Incorrect use of inhaler devices by patients with asthma is common and can adversely affect clinical outcomes. Devices that are straightforward to use are less likely to result in dosing errors and can improve patients' satisfaction with therapy and adherence. A novel dry-powder formulation of the rescue bronchodilator albuterol (salbutamol) administered using a multidose dry-powder inhaler (mDPI; RespiClick™) has recently been approved in the USA., Areas Covered: Studies on the albuterol mDPI were identified in searches of PubMed and www.clinicaltrials.gov . Pharmacokinetic, pharmacodynamic, efficacy, and safety data, and patients' experiences with the albuterol mDPI are presented., Expert Opinion: The albuterol mDPI has an efficacy/tolerability profile consistent with other inhaled forms of albuterol, and is reliable, easy to use, and associated with a high level of patient satisfaction. This is the first albuterol dry-powder inhaler (DPI) to become available in the USA, with most other formulations being delivered using a pressurized metered-dose inhaler (pMDI). The availability of a breath-actuated device avoids the challenge of coordinating actuation and breathing when using pMDIs, and could simplify treatment for patients also using a DPI for controller medication. Additional features of RespiClick, such as an integrated dose counter and minimal pre-inhalation preparation, facilitate its use.

The propellant-free Combivent Respimat Soft Mist Inhaler (CVT-R) was developed to replace the chlorofluorocarbon-propelled Combivent metered-dose inhaler (CVT-MDI). This steady-state pharmacokinetic (PK) substudy evaluated drug lung-delivery efficiency, using data from two phase III safety and efficacy trials. PK parameters were obtained from well-controlled population PK analyses. Area under the plasma concentration-time curve (AUC), maximum observed plasma concentration (C(max)), and minimum observed plasma concentration (C(min)) showed systemic exposure to ipratropium bromide and albuterol delivered via the CVT-R was proportional to ex-mouthpiece delivered dose. Although the labeled dose of ipratropium bromide in the CVT-R was half that in the CVT-MDI, the systemic exposure was comparable. No PK interaction for the ipratropium bromide and albuterol Respimat drug components was demonstrated. Ipratropium bromide alone resulted in similar exposure to the combination of ipratropium bromide and albuterol. These results show that CVT-R delivers drug more efficiently to the lung than CVT-MDI., (© 2016 The Authors. Clinical and Translational Science published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.)

Background: Salbutamol abuse detection by athletes is based on a urinary upper threshold defined by the World Anti-Doping Agency (WADA). However, this threshold was determined in healthy, untrained individuals and after a dose of salbutamol inhaled that might not really mirror the condition of asthmatic athletes and the experts's guidelines for asthma management. We aimed to revise this threshold in accordance with recommended clinical practice (that appear to be different from the actual WADA recommendation) and in exercise conditions., Methods: For the present open-label design study, we included 12 trained male cyclists (20 to 40 y/o) with asthma. Differently from the previous pharmacokinetic study supporting the actual salbutamol urinary upper threshold, we decided to administer a close to recommended clinical practice daily dose of 3x200 μg.d(-1) inhaled salbutamol (instead of 1600 μg.d(-1) as authorized by the anti-doping policy). Urine salbutamol concentration was quantified by liquid chromatography-tandem ion trap mass spectrometry and corrected for urine density, at rest and after a 90-min cycling effort at 70-80 % of the maximal aerobic power., Results: The maximum urine salbutamol concentration value peaked after the cycling effort and was 510 ng.mL(-1). That is twice lower than the actual WADA threshold to sanction salbutamol abuse, this "legal" threshold being based on pharmacokinetic data after a daily dose that is 8 fold the total dose sequentially administrated in our study. Considering its 95 % confidence interval, this threshold value could be more stringent., Conclusion: By using conditions in accordance with the experts' clinical and safety guidelines for asthma management in athletes undergoing an intense exercise bout, our study suggests that the urine salbutamol concentration threshold could be lowered to redefine the rule supporting the decision to sanction an athlete for salbutamol abuse.

A new method for determining salbutamol in hair of sheep by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was established. Samples were extracted with 0.1M of HCl solution. The mixture was heated to 60 °C in a water bath and kept at this temperature for 4h. The extracts were purified through SPE method and then dried with nitrogen. Residues were redissolved in mobile phase. The target compound was determined by UPLC-MS/MS with BEH-C18 column. The usefulness and feasibility of different treatment procedures of hair containing salbutamol were evaluated. The range of linearity was 1-100 ng/g. The LOD was 0.3 ng/g, and the LOQ was 1 ng/g. Recoveries were 89-106%, and coefficients of variation were 3.2-13.9%. Pharmacokinetics of salbutamol was studied in healthy sheep after oral administration of 150 μg/kg body weight salbutamol for 21 consecutive days. Salbutamol residues in hair were still detected after 21 days of administration., (Copyright © 2015 Elsevier B.V. All rights reserved.)