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Salmeterol xinafoate (SAM) and fluticasone propionate (FLU) are one of the drug combinations used together in the treatment of lung diseases such as asthma and chronic obstructive pulmonary disease (COPD). The aim of this study is to investigate the usability of novel dual molecular imprinted nanoparticles (poly(2-hydroxyethyl methacrylate-N-methacryloyl-(L)-alanine-N-methacryloyl-(L)-histidine) [p(HEMA-MAAL-MAH)], abbr. DMIPNPs) as a controlled drug release systems. In this study, SAM and FLU drugs were chosen as model drugs because they are used in the treatment of these diseases. DMIPNPs were prepared by surfactant-free emulsion polymerization method and characterized by scanning electron microscopy (SEM) and fourier transform infrared spectrometer (FTIR). In in vitro drug release experiments, drug release conditions were optimized. SAM and FLU release from DMIPNPs experiments were also performed in the simulated lung fluid (SLF). The amount of released SAM and FLU were found as 4.79 and 5.68 mg/g in the SLF medium at the end of 48 h, respectively. The release kinetics of SAM and FLU from DMIPNPs were calculated in the SLF medium. The release of SAM and FLU was determined to be compatible with the Higuchi release models. According to these results, these DMIPNPs, dual-template molecular imprinted nanoparticles with dual monomers, are promising materials that can be used in the controlled release of two different drugs. [ABSTRACT FROM AUTHOR]

Abstract Fixed dose combinations (FDCs) incorporating two or three medicines in a single inhaler have been created to enhance patient compliance and hence clinical outcomes. However, the development of dry powder inhalers (DPIs), particularly for FDCs, faces challenges pertinent to formulation uniformity and reproducibility. Therefore, this project aimed to employ nanotechnology to develop a FDC of DPIs for market-leading medicines—fluticasone propionate (FP) and salmeterol xinafoate (SAL)—for asthma management. Nanoaggregates were prepared using a novel biocompatible and biodegradable poly(ester amide) based on the amino acid tyrosine, utilising a one-step interfacial polymerisation process. The produced tyrosine poly (ester amide) drug-loaded nanoparticles were evaluated for content uniformity, PSA, FTIR, TEM, DSC, XRD and aerodynamic performance (in vitro and in vivo). The optimised formulation demonstrated high entrapment efficiency– > 90%. The aerodynamic performance in terms of the emitted dose, fine particle fraction and respirable dose was superior to the carrier-based marketed product. In-vivo studies showed that FP (above the marketed formulation) and SAL reached the lungs of mice in a reproducible manner. These results highlight the superiority of novel FDC FP/SAL nanoparticles prepared via a one-step process, which can be used as a cost-effective and efficient method to alleviate the burden of asthma.

Fixed dose combinations (FDCs) incorporating two or three medicines in a single inhaler have been created to enhance patient compliance and hence clinical outcomes. However, the development of dry powder inhalers (DPIs), particularly for FDCs, faces challenges pertinent to formulation uniformity and reproducibility. Therefore, this project aimed to employ nanotechnology to develop a FDC of DPIs for market-leading medicines—fluticasone propionate (FP) and salmeterol xinafoate (SAL)—for asthma management. Nanoaggregates were prepared using a novel biocompatible and biodegradable poly(ester amide) based on the amino acid tyrosine, utilising a one-step interfacial polymerisation process. The produced tyrosine poly (ester amide) drug-loaded nanoparticles were evaluated for content uniformity, PSA, FTIR, TEM, DSC, XRD and aerodynamic performance (in vitro and in vivo). The optimised formulation demonstrated high entrapment efficiency– > 90%. The aerodynamic performance in terms of the emitted dose, fine particle fraction and respirable dose was superior to the carrier-based marketed product. In-vivo studies showed that FP (above the marketed formulation) and SAL reached the lungs of mice in a reproducible manner. These results highlight the superiority of novel FDC FP/SAL nanoparticles prepared via a one-step process, which can be used as a cost-effective and efficient method to alleviate the burden of asthma. [ABSTRACT FROM AUTHOR]

BackgroundPharmacogenetic studies in asthma cohorts, primarily made up of White people of European descent, have identified loci associated with response to inhaled beta agonists and corticosteroids (ICSs). Differences exist in how individuals from different ancestral backgrounds respond to long-acting beta agonist (LABA) and ICSs. Therefore, we sought to understand the pharmacogenetic mechanisms regulating therapeutic responsiveness in individuals of African descent.MethodsWe did ancestry-based pharmacogenetic studies of children (aged 5-11 years) and adolescents and adults (aged 12-69 years) from the Best African Response to Drug (BARD) trials, in which participants with asthma uncontrolled with low-dose ICS (fluticasone propionate 50 μg in children, 100 μg in adolescents and adults) received different step-up combination therapies. The hierarchal composite outcome of pairwise superior responsiveness in BARD was based on asthma exacerbations, a 31-day difference in annualised asthma-control days, or a 5% difference in percentage predicted FEV1. We did whole-genome admixture mapping of 15 159 ancestral segments within 312 independent regions, stratified by the two age groups. The two co-primary outcome comparisons were the step up from low-dose ICS to the quintuple dose of ICS (5 × ICS: 250 μg twice daily in children and 500 μg twice daily in adolescents and adults) versus double dose (2-2·5 × ICS: 100 μg twice daily in children, 250 μg twice daily in adolescents and adults), and 5 × ICS versus 100 μg fluticasone plus a LABA (salmeterol 50 μg twice daily). We used a genome-wide significance threshold of p

Most drugs acting on G-protein-coupled receptors target the orthosteric binding pocket where the native hormone or neurotransmitter binds. There is much interest in finding allosteric ligands for these targets because they modulate physiologic signaling and promise to be more selective than orthosteric ligands. Here we describe a newly developed allosteric modulator of the β2-adrenergic receptor (β2AR), AS408, that binds to the membrane-facing surface of transmembrane segments 3 and 5, as revealed by X-ray crystallography. AS408 disrupts a water-mediated polar network involving E1223.41 and the backbone carbonyls of V2065.45 and S2075.46. The AS408 binding site is adjacent to a previously identified molecular switch for β2AR activation formed by I3.40, P5.50 and F6.44. The structure reveals how AS408 stabilizes the inactive conformation of this switch, thereby acting as a negative allosteric modulator for agonists and positive allosteric modulator for inverse agonists.

BackgroundMorbidity from asthma is disproportionately higher among black patients than among white patients, and black patients constitute the minority of participants in trials informing treatment. Data indicate that patients with inadequately controlled asthma benefit more from addition of a long-acting beta-agonist (LABA) than from increased glucocorticoids; however, these data may not be informative for treatment in black patients.MethodsWe conducted two prospective, randomized, double-blind trials: one involving children and the other involving adolescents and adults. In both trials, the patients had at least one grandparent who identified as black and had asthma that was inadequately controlled with low-dose inhaled glucocorticoids. We compared combinations of therapy, which included the addition of a LABA (salmeterol) to an inhaled glucocorticoid (fluticasone propionate), a step-up to double to quintuple the dose of fluticasone, or both. The treatments were compared with the use of a composite measure that evaluated asthma exacerbations, asthma-control days, and lung function; data were stratified according to genotypic African ancestry.ResultsWhen quintupling the dose of fluticasone (to 250 μg twice a day) was compared with adding salmeterol (50 μg twice a day) and doubling the fluticasone (to 100 μg twice a day), a superior response occurred in 46% of the children with quintupling the fluticasone and in 46% of the children with doubling the fluticasone and adding salmeterol (P = 0.99). In contrast, more adolescents and adults had a superior response to added salmeterol than to an increase in fluticasone (salmeterol-low-dose fluticasone vs. medium-dose fluticasone, 49% vs. 28% [P = 0.003]; salmeterol-medium-dose fluticasone vs. high-dose fluticasone, 49% vs. 31% [P = 0.02]). Neither the degree of African ancestry nor baseline biomarkers predicted a superior response to specific treatments. The increased dose of inhaled glucocorticoids was associated with a decrease in the ratio of urinary cortisol to creatinine in children younger than 8 years of age.ConclusionsIn contrast to black adolescents and adults, almost half the black children with poorly controlled asthma had a superior response to an increase in the dose of an inhaled glucocorticoid and almost half had a superior response to the addition of a LABA. (Funded by the National Heart, Lung, and Blood Institute; BARD ClinicalTrials.gov number, NCT01967173.).

BackgroundLoss of bronchoprotection (LOBP) with a regularly used long-acting β2-adrenergic receptor agonist (LABA) is well documented. LOBP has been attributed to β2-adrenergic receptor (B2AR) downregulation, a process requiring farnesylation, which is inhibited by alendronate.ObjectiveWe sought to determine whether alendronate can reduce LABA-associated LOBP in inhaled corticosteroid (ICS)-treated patients.MethodsWe conducted a randomized, double-blind, placebo-controlled, parallel-design, proof-of-concept trial. Seventy-eight participants with persistent asthma receiving 250 μg of fluticasone twice daily for 2 weeks were randomized to receive alendronate or placebo while initiating salmeterol for 8 weeks. Salmeterol-protected methacholine challenges (SPMChs) and PBMC B2AR numbers (radioligand binding assay) and signaling (cyclic AMP ELISA) were assessed before randomization and after 8 weeks of ICS plus LABA treatment. LOBP was defined as a more than 1 doubling dose reduction in SPMCh PC20 value.ResultsThe mean doubling dose reduction in SPMCh PC20 value was 0.50 and 0.27 with alendronate and placebo, respectively (P = .62). Thirty-eight percent of participants receiving alendronate and 33% receiving placebo had LOBP (P = .81). The after/before ICS plus LABA treatment ratio of B2AR number was 1.0 for alendronate (P = .86) and 0.8 for placebo (P = .15; P = .31 for difference between treatments). The B2AR signaling ratio was 0.89 for alendronate (P = .43) and 1.02 for placebo (P = .84; P = .44 for difference). Changes in lung function and B2AR number and signaling were similar between those who did and did not experience LOBP.ConclusionThis study did not find evidence that alendronate reduces LABA-associated LOBP, which relates to the occurrence of LOBP in only one third of participants. LOBP appears to be less common than presumed in concomitant ICS plus LABA-treated asthmatic patients. B2AR downregulation measured in PBMCs does not appear to reflect LOBP.

The physicochemical features of the chiral separation of bronchodilators, isomers of salmeterol xinafoate and the salmeterol base, are studied by supercritical fluid chromatography (SFC) in the analytical and preparative modes. The effects of the composition of the mobile phase, temperature, and pressure on retention, peak shapes, and selectivity of the chiral resolution of the salmeterol base racemate in the analytical chromatography mode is studied. The optimal conditions for the separation of the salmeterol base enantiomers on a Chiralpak IG analytical column in supercritical CO2 (SC-CO2) are determined. The behavior of salmeterol xinafoate is studied under conditions of preparative SFC analysis. [ABSTRACT FROM AUTHOR]

Salmeterol is a partial agonist for the β2 adrenergic receptor (β2AR) and the first long-acting β2AR agonist to be widely used clinically for the treatment of asthma and chronic obstructive pulmonary disease. Salmeterol's safety and mechanism of action have both been controversial. To understand its unusual pharmacological action and partial agonism, we obtained the crystal structure of salmeterol-bound β2AR in complex with an active-state-stabilizing nanobody. The structure reveals the location of the salmeterol exosite, where sequence differences between β1AR and β2AR explain the high receptor-subtype selectivity. A structural comparison with the β2AR bound to the full agonist epinephrine reveals differences in the hydrogen-bond network involving residues Ser2045.43 and Asn2936.55. Mutagenesis and biophysical studies suggested that these interactions lead to a distinct active-state conformation that is responsible for the partial efficacy of G-protein activation and the limited β-arrestin recruitment for salmeterol.

The ability of chemically distinct ligands to produce different effects on the same G protein-coupled receptor (GPCR) has interesting therapeutic implications, but, if excessively propagated downstream, would introduce biologic noise compromising cognate ligand detection. We asked whether cells have the ability to limit the degree to which chemical diversity imposed at the ligand-GPCR interface is propagated to the downstream signal. We carried out an unbiased analysis of the integrated cellular response elicited by two chemically and pharmacodynamically diverse β-adrenoceptor agonists, isoproterenol and salmeterol. We show that both ligands generate an identical integrated response, and that this stereotyped output requires endocytosis. We further demonstrate that the endosomal β2-adrenergic receptor signal confers uniformity on the downstream response because it is highly sensitive and saturable. Based on these findings, we propose that GPCR signaling from endosomes functions as a biologic noise filter to enhance reliability of cognate ligand detection.

One of the key challenges in developing a dry powder inhaler (DPI) of an inhalable potent fixed-dose combination (FDC) is the ability of the formulation to generate an effective and reproducible aerosol able to reach the lower parts of the lungs. Herein, a one-step approach is presented to expedite the synthesis of nanoaggregates made from a biocompatible and biodegradable polyamide based on L-lysine amino acid employing market-leading active pharmaceutical ingredients (fluticasone propionate (FP) and salmeterol xinafoate (SAL)) for the management of asthma. The nanoaggregates were synthesized using interfacial polycondensation that produced nanocapsules with an average particle size of 226.7 ± 35.3 nm and zeta potential of −30.6 ± 4.2 mV. Differential scanning calorimetric analysis and x-ray diffraction, as well as scanning electron microscopy of the produced FDC, revealed the ability of the produced nanocapsules to encapsulate the two actives and display the best aerodynamic performance. The FDC nanocapsules displayed 88.5% and 98.5% of the emitted dose for FP and SAL, respectively. The fine particle fraction of the nominated dose was superior to the marketed product (Seretide Diskus®, Brentford, United Kingdom). The in-vitro release study showed an extended drug release profile. Our findings suggest that nanoaggregates using polyamides based on L-lysine and interfacial polycondensation can serve as a good platform for pulmonary drug delivery of FDC systems. [ABSTRACT FROM AUTHOR]

In this study, novel double molecular imprinted nanoparticles (DMIP nanoparticles) with multi-functional monomers were prepared for adsorption of salmeterol xinafoate (SAM) and fluticasone propionate (FLU) drugs. For this purpose, SAM and FLU imprinted poly (2-hydroxyethyl methacrylate-N-methacryloyl-(L)-alanine-N-methacryloyl-(L)-histidine) [p(HEMA-MAAL-MAH)] nanoparticles were synthesized by surfactant-free emulsion polymerization method. After the characterization, adsorption conditions were optimized, and the adsorption kinetics parameters were also calculated. In the selectivity experiments, budesonide (BS) and formoterol fumarate (FF) drugs were used as competitive drugs. These novel development DMIP nanoparticles have the potential for use in many different areas, for purposes such as drug release, separation, and purification. [ABSTRACT FROM AUTHOR]

A molecular imprinted polymer (MIP) was computationally designed and synthesized for the selective extraction of salmeterol xinafoate (SLX) from human serum. In this study, semi‐empirical PM3 calculations were used to find a suitable functional monomer (FM), the ratio of template (T) to FM, and types of crosslinkers. MIPs were synthesized with 2‐hydroxyethyl methacrylate (HEMA) with T:FM mol ratios of 1:6 and 1:4 and ethylene glycol dimethacrylate (EGDMA) or trimethylolpropane trimethacrylate (TRIM) as a crosslinker. On the basis of computational and experimental results, HEMA and TRIM in the mol ratio 1:6 of T‐FM (MIP3) were found to be the best choices of FM and crosslinker, respectively. These polymers were then used as a selective sorbent to develop a molecularly imprinted solid‐phase extraction procedure followed by high performance liquid chromatography with UV detection for the determination of SLX in serum. The extraction ability of MIP3 was excellent with a recovery of 92.17% ± 2.66% of SLX in spiked serum, and 91.15% ± 1.12% when SLX was spiked as a mixture with another analogous structure. By comparing the performance of the synthesized sorbent with a C‐18 cartridge with a recovery of 79.11% ± 2.96%, it was determined that MIP had better performance over the latter. On the basis of these results, the imprinted receptor MIPs, especially MIP 3, can be applied for the direct extraction of SLX in clinical analysis. [ABSTRACT FROM AUTHOR]

Background: Chronic obstructive pulmonary disease treatment is informed by randomised controlled trial results, but it is unclear if these findings apply to people excluded from these trials. We used data from the TORCH (TOwards a Revolution in COPD Health) randomised controlled trial to validate non-interventional methods for assessing the clinical effectiveness of chronic obstructive pulmonary disease treatment in the UK Clinical Practice Research Datalink, before applying these methods to the analysis of people who would have been excluded from TORCH. Objectives: To validate the use of non-interventional Clinical Practice Research Datalink data and methods for estimating chronic obstructive pulmonary disease treatment effects against trial results, and, using validated methods, to determine treatment effects in people who would have been excluded from the TORCH trial. Design: A historical non-interventional cohort design, including validation against randomised controlled trial results. Setting: The UK Clinical Practice Research Datalink. Participants: People aged ≥ 18 years with chronic obstructive pulmonary disease registered in Clinical Practice Research Datalink GOLD between January 2000 and January 2017. For objective 1, we prepared a cohort that was analogous to the TORCH trial cohort by applying TORCH trial inclusion/exclusion criteria followed by individual matching to TORCH trial participants. For objectives 2 and 3, we prepared cohorts that were analogous to the TORCH trial that, nevertheless, would not have been eligible for the TORCH trial because of age, asthma, comorbidity or mild disease. Interventions: The long-acting beta-2 agonist and inhaled corticosteroid combination product Seretide (GlaxoSmithKline plc) [i.e. fluticasone propionate plus salmeterol (FP-SAL)] compared with (1) no FP-SAL exposure or (2) exposure to salmeterol (i.e. the long-acting beta-2 agonist) only. Main outcome measures: Exacerbations, mortality, pneumonia and time to treatment change. Results: For objective 1, the exacerbation rate ratio was comparable to that in the TORCH trial for FP-SAL compared with salmeterol (0.85, 95% confidence interval 0.74 to 0.97, vs. TORCH trial 0.88, 95% confidence interval 0.81 to 0.95), but not for FP-SAL compared with no FP-SAL (1.30, 95% confidence interval 1.19 to 1.42, vs. TORCH trial 0.75, 95% confidence interval 0.69 to 0.81). Active comparator results were also consistent with the TORCH trial for mortality (hazard ratio 0.93, 95% confidence interval 0.65 to 1.32, vs. TORCH trial hazard ratio 0.93, 95% confidence interval 0.77 to 1.13) and pneumonia (risk ratio 1.39, 95% confidence interval 1.04 to 1.87, vs. TORCH trial risk ratio 1.47, 95% confidence interval 1.25 to 1.73). For objectives 2 and 3, active comparator results were consistent with the TORCH trial for exacerbations, with the exception of people with milder chronic obstructive pulmonary disease, in whom we observed a stronger protective association (risk ratio 0.56, 95% confidence interval 0.46 to 0.70, vs. TORCH trial risk ratio 0.85, 95% confidence interval 0.74 to 0.97). For the analysis of mortality, we saw a lack of association with being prescribed FP-SAL (vs. being prescribed salmeterol), with the exception of those with prior asthma, for whom we observed an increase in mortality (hazard ratio 1.49, 95% confidence interval 1.21 to 1.85, vs. TORCH trial-analogous HR 0.93, 95% confidence interval 0.64 to 1.32). Conclusions: Routinely collected electronic health record data can be used to successfully measure chronic obstructive pulmonary disease treatment effects when comparing two treatments, but not for comparisons between active treatment and no treatment. Analyses involving patients who would have been excluded from trials mostly suggests that treatment effects for FP-SAL are similar to trial effects, although further work is needed to characterise a small increased risk of death in those with concomitant asthma. Limitations: Some of our analyses had small numbers. Future work: The differences in treatment effects that we found should be investigated further in other data sets. Currently recommended chronic obstructive pulmonary disease inhaled combination therapy (other than FP-SAL) should also be investigated using these methods. Funding: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 51. See the NIHR Journals Library website for further project information.

Background: The lower respiratory tract of the landrace pig has close anatomical and physiological similarities with that of the human, and hence, for inhalation studies this species is well suited for biopharmaceutical research. Methods: The objective of this study was to evaluate pharmacokinetics in pigs following one dose of Diskus™ Seretide™ forte device, labeled 500/50 fluticasone propionate (FP) and salmeterol xinafoate (SX), respectively. The PreciseInhale™ (PI) instrument was used to actuate the inhaler for in vitro testing and aerosol dosing to pigs. In vitro, the aerosol was characterized with a cascade impactor with respect to mass median aerodynamic diameter, geometric standard deviation, and fine particle dose. In vivo, dry powder inhalation exposure was delivered as a short bolus dose, to anesthetized and mechanically ventilated landrace pigs. In addition to plasma PK, PK assessment of airway epithelial lining fluid (ELF) was used in this study. ELF of the depth of three to fourth airway generation of the right lung was accessed using standard bronchoscopy and a synthetic absorptive matrix. Results and Conclusions: Dry powder inhalation exposures with good consistency and well characterized aerosols to the pig lung were achieved by the use of the PreciseInhale™ instrument. Drug concentrations of ELF for both FP and SX were demonstrated to be four to five orders of magnitude higher than its corresponding systemic plasma drug concentrations. Clinical PK following inhalation of the same dose was used as benchmark, and the clinical study did demonstrate similar plasma PK profiles and drug exposures of both FP and SX as the current pig study. Two factors explain the close similarity of PK (1) similiar physiology between species and (2) the consistency of dosing to animals. To conclude, our study demonstrated the utility and translational potential of conducting PK studies in pigs in the development of inhaled pharmaceuticals. [ABSTRACT FROM AUTHOR]

In development of inhaled drugs- and formulations the measured concentration in the systemic circulation is often used as a surrogate for local dosimetry in the lungs. To further elucidate regional differences in the fate of drugs in the lungs, different aerodynamic sizes of aerosols have been used to target major airway regions. An alternative approach to achieve regional targeting of aerosols, is to use a defined aerosol bolus together with a bolus breath hold strategy. A small volume of test aerosol is intercalated and stopped at different penetration depths, to achieve increased drug deposition at chosen lung locations. Drug permeation from the lung regions is then investigated by repeatedly sampling venous blood from the systemic circulation. The PreciseInhale® (PI) exposure platform was developed to allow generation of aerosols from different sources, including clinical inhalers, into a holding chamber, for subsequent use with alternative exposure modules in vitro and in vivo. In the current first-in-human study was investigated the feasibility of a new clinical exposure module added to the PI system. By extracting aerosol puffs from a medical inhaler for subsequent delivery to volunteers, it was possible to administer whole lung exposures, as well as regional targeting exposures. Aerosols containing 250 µg/25 µg fluticasone propionate (FP)/salmeterol xinafoate (SMX) were automatically actuated and extracted from the pressurized Metered Dose Inhaler (pMDI) Evohaler Seretide forte into the PI system's holding chamber, then administered to the healthy volunteers using controlled flowrate and volume exposure cycles. Two main comparisons were made by measuring the systemic PK response: I. One label dose directly from the inhaler to the subject was compared to the same dose extracted from the pMDI into the PI system and then administered to the subject. II A small aerosol bolus at a penetration level in the central airways was compared to a small aerosol bolus at a penetration level in the peripheral lung. When one inhaler dose was administered via the PI system, the absorbed dose, expressed as AUC24, was approximately twice as high and the CV was less than half, compared to direct inhalation from the same pMDI. Bolus breath hold targeting of drugs from the same aerosol mixture to the peripheral lung and the central airways showed a difference in their appearance in the systemic circulation. Normalized to the same deposited dose, SMX had a 57 % higher C max in the peripheral lung compared to the central airways. However, from 6 to 24 h after dosing the systemic concentrations of SMX from both regions were quite similar. FP had parallel concentrations curves with a 23 % higher AUC24 in the peripheral lung with no noticeable elevation around C max. The permeability of these two substances from similar sized aerosols was indeed higher in the thinner air/blood barriers of the peripheral lung compared to the central airways, but differences as measured on the venous side of the circulation were not dramatic. In conclusion, the PI system provided better control of actuation, aspiration, and dispensation of aerosols from the clinical inhaler and thereby delivered higher quality read outs of pharmacokinetic parameters such as t max , C max , and AUC. Improved performance, using PI system, can likely also be employed for studying regional selectivity of other responses in the lungs, for use in drug development. [Display omitted] [ABSTRACT FROM AUTHOR]

One of the key challenges in developing a dry powder inhaler (DPI) of an inhalable potent fixed-dose combination (FDC) is the ability of the formulation to generate an effective and reproducible aerosol able to reach the lower parts of the lungs. Herein, a one-step approach is presented to expedite the synthesis of nanoaggregates made from a biocompatible and biodegradable polyamide based on L-lysine amino acid employing market-leading active pharmaceutical ingredients (fluticasone propionate (FP) and salmeterol xinafoate (SAL)) for the management of asthma. The nanoaggregates were synthesized using interfacial polycondensation that produced nanocapsules with an average particle size of 226.7 ± 35.3 nm and zeta potential of −30.6 ± 4.2 mV. Differential scanning calorimetric analysis and x-ray diffraction, as well as scanning electron microscopy of the produced FDC, revealed the ability of the produced nanocapsules to encapsulate the two actives and display the best aerodynamic performance. The FDC nanocapsules displayed 88.5% and 98.5% of the emitted dose for FP and SAL, respectively. The fine particle fraction of the nominated dose was superior to the marketed product (Seretide Diskus®, Brentford, United Kingdom). The in-vitro release study showed an extended drug release profile. Our findings suggest that nanoaggregates using polyamides based on L-lysine and interfacial polycondensation can serve as a good platform for pulmonary drug delivery of FDC systems.

BackgroundTiotropium has activity as an asthma controller. However, predictors of a positive response to tiotropium have not been described.ObjectiveWe sought to describe individual and differential responses of asthmatic patients to salmeterol and tiotropium when added to an inhaled corticosteroid, as well as predictors of a positive clinical response.MethodsData from the double-blind, 3-way, crossover National Heart, Lung, and Blood Institute's Asthma Clinical Research Network's Tiotropium Bromide as an Alternative to Increased Inhaled Glucocorticoid in Patients Inadequately Controlled on a Lower Dose of Inhaled Corticosteroid (ClinicalTrials.gov number, NCT00565266) trial were analyzed for individual and differential treatment responses to salmeterol and tiotropium and predictors of a positive response to the end points FEV1, morning peak expiratory flow (PEF), and asthma control days (ACDs).ResultsAlthough approximately equal numbers of patients showed a differential response to salmeterol and tiotropium in terms of morning PEF (n = 90 and 78, respectively) and ACDs (n = 49 and 53, respectively), more showed a differential response to tiotropium for FEV1 (n = 104) than salmeterol (n = 62). An acute response to a short-acting bronchodilator, especially albuterol, predicted a positive clinical response to tiotropium for FEV1 (odds ratio, 4.08; 95% CI, 2.00-8.31; P < .001) and morning PEF (odds ratio, 2.12; 95% CI, 1.12-4.01; P = 0.021), as did a decreased FEV1/forced vital capacity ratio (FEV1 response increased 0.39% of baseline for every 1% decrease in FEV1/forced vital capacity ratio). Higher cholinergic tone was also a predictor, whereas ethnicity, sex, atopy, IgE level, sputum eosinophil count, fraction of exhaled nitric oxide, asthma duration, and body mass index were not.ConclusionAlthough these results require confirmation, predictors of a positive clinical response to tiotropium include a positive response to albuterol and airway obstruction, factors that could help identify appropriate patients for this therapy.

The lung is an attractive target organ for inhalation of RNA therapeutics, such as small interfering RNA (siRNA). However, clinical translation of siRNA drugs for application in the lung is hampered by many extra- and intracellular barriers. We previously developed hybrid nanoparticles consisting of an siRNA-loaded nanosized hydrogel (nanogel) core coated with Curosurf®, a clinically used pulmonary surfactant. The surfactant shell was shown to markedly improve particle stability and promote intracellular siRNA delivery, both in vitro and in vivo. However, the full potential of siRNA nanocarriers is typically not reached as they are rapidly trafficked towards lysosomes for degradation and only a fraction of the internalized siRNA cargo is able to escape into the cytosol. We recently reported on the repurposing of widely applied cationic amphiphilic drugs (CADs) as siRNA delivery enhancers. Due to their physicochemical properties, CADs passively accumulate in the (endo)lysosomal compartment causing a transient permeabilization of the lysosomal membrane, which facilitates cytosolic drug delivery. In this work, we assessed a selection of cationic amphiphilic β 2 -agonists (i.e., salbutamol, formoterol, salmeterol and indacaterol) for their ability to enhance siRNA delivery in a lung epithelial and macrophage cell line. These drugs are widely used in the clinic for their bronchodilating effect in obstructive lung disease. As opposed to the least hydrophobic drugs salbutamol and formoterol, the more hydrophobic long-acting β 2 -agonist (LABA) salmeterol promoted siRNA delivery in both cell types for both uncoated and surfactant-coated nanogels, whereas indacaterol showed this effect solely in lung epithelial cells. Our results demonstrate the potential of both salmeterol and indacaterol to be repurposed as adjuvants for nanocarrier-mediated siRNA delivery to the lung, which could provide opportunities for drug combination therapy., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Rationale: Some drugs can only be dispensed in multiple‐dose containers. Multiple‐dose packaging may pose a problem for hospitals in terms of drug wastage and cost. Oral inhalers, such as fluticasone propionate and salmeterol combination inhalers, are only available as multiple‐dose formats in Canada. Objectives: The objectives of this study are to quantify the amount of fluticasone propionate and salmeterol combination inhaler waste and to assess possible factors that could be contributing to waste. Methods: A retrospective chart review of 189 patients was conducted. Patients were included if they had received an order for fluticasone propionate and salmeterol combination inhaler at one of the 12 acute hospital sites of Fraser Health Authority. The primary outcome was the proportion of patients who were dispensed one or more inhalers unnecessarily. The number of inhalers dispensed was compared with the number of inhalers needed to complete a patient's order duration. The chart was also reviewed for possible factors that could have contributed to extra inhalers being dispensed unnecessarily. Results: Thirty‐seven patients (19.6%) had at least one inhaler dispensed unnecessarily and thus wasted. About 17.4% of the total amount of inhalers dispensed were dispensed unnecessarily, and 76.3% of doses dispensed were wasted. The cost of inhalers wasted for our sample was $5151.12 (CAD). The most common factors that contributed to inhaler waste appeared to be loss of medication during patient transfers and storage of inhalers as wardstock. Conclusions: The use of drugs that are only available in multiple‐dose formats results in significant drug wastage and unnecessary health care expenditure. To minimize wastage of drug product, procedures could be implemented to ensure that drugs are properly transferred with the patient when a patient transfers locations in the hospital. As well, a review of wardstock inventory may minimize waste. Further assessment of multiple‐dose drug product waste and evaluations of methods to mitigate waste are encouraged. [ABSTRACT FROM AUTHOR]

Chitosan (CS) is a natural polysaccharide, widely studied in the past due to its unique properties such as biocompatibility, biodegradability and non-toxicity. Chemical modification of CS is an effective pathway to prepare new matrices with additional functional groups and improved properties, such as increment of hydrophilicity and swelling rate, for drug delivery purposes. In the present study, four derivatives of CS with trans-aconitic acid (t-Acon), succinic anhydride (Succ), 2-hydroxyethyl acrylate (2-HEA) and acrylic acid (AA) were prepared, and their successful grafting was confirmed by FTIR and 1H-NMR spectroscopies. Neat chitosan and its grafted derivatives were fabricated for the encapsulation of fluticasone propionate (FLU) and salmeterol xinafoate (SX) drugs, used for chronic obstructive pulmonary disease (COPD), via the ionotropic gelation technique. Scanning electron microscopy (SEM) micrographs demonstrated that round-shaped microparticles (MPs) were effectively prepared with average sizes ranging between 0.4 and 2.2 μm, as were measured by dynamic light scattering (DLS), while zeta potential verified in all cases their positive charged surface. FTIR spectroscopy showed that some interactions take place between the drugs and the polymeric matrices, while X-ray diffraction (XRD) patterns exhibited that both drugs were encapsulated in MPs’ interior with a lower degree of crystallinity than the neat drugs. In vitro release studies of FLU and SX exposed a great amelioration in the drugs’ dissolution profile from all modified CS’s MPs, in comparison to those of neat drugs. The latter fact is attributed to the reduction in crystallinity of the active substances in the MPs’ interior.

It was suggested that impaired β-adrenergic relaxation in spontaneously hypertensive rats (SHR) might contribute to their high blood pressure (BP). Our study was focused on isoprenaline-induced dilatation of conduit femoral or resistance mesenteric arteries and on isoprenaline-induced BP reduction in SHR and Wistar-Kyoto rats (WKY). We confirmed decreased β-adrenergic relaxation of SHR femoral arteries due to the absence of its endothelium-independent component, whereas endothelium-dependent component of β-adrenergic smooth muscle relaxation was similar in both strains. Conversely, isoprenaline-induced relaxation of resistance mesenteric arteries was similar in both strains and this was true for endothelium-dependent and endothelium-independent components. We observed moderately reduced sensitivity of SHR mesenteric arteries to salmeterol (β 2 -adrenergic agonist) and this strain difference disappeared after endothelium removal. However, there was no difference in mesenteric arteries relaxation by dobutamine (β 1 -adrenergic agonist) which was independent of endothelium. The increasing isoprenaline doses elicited similar BP decrease in both rat strains, although BP sensitivity to isoprenaline was slightly decreased in SHR. The blockade of cyclooxygenase (indomethacin) and NO synthase (L-NAME) further reduced BP sensitivity to isoprenaline in SHR. On the other hand, salmeterol elicited similar BP decrease in both strains and the blockade of cyclooxygenase and NO synthase increased BP sensitivity to salmeterol in SHR as compared to WKY. In conclusion, attenuated β-adrenergic vasodilatation of conduit arteries of SHR but similar β-adrenergic relaxation of resistance mesenteric arteries from WKY and SHR and their similar BP response to β-adrenergic agonists do not support major role of altered β-adrenergic vasodilatation for high BP in genetic hypertension., Competing Interests: Declaration of competing interest None., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

The aim of this study was to develop a novel fluticasone propionate (FP) and salmeterol xinafoate (SX)-loaded dry powder inhaler (DPI) system, which was composed of powder formulation and performance. The air flow resistances were determined with various types of DPI device, showing that the modified RS01 device gave the specific resistance similar to the commercial DPI device. The particle properties of FP, SX, and inhalation grade lactose particles, such as particle size, size distribution, and fine content, were assessed. Subsequently, the aerodynamic behaviors of the DPI powder formulations were evaluated by thein vitrodeposition of drugs in the DPI products using Andersen cascade impactor. Amongst the DPI powder formulations tested, the formulation composed of FP, SX, Respitose®SV003, Respitose®SV010, and Respitose®ML006 at the weight ratio of 0.5/0.145/19/19/2 gave depositions, emitted dose, fine particle dose, fine particle fraction, and mass median aerodynamic diameter of drugs similar to the commercial product, suggesting that they had similar aerodynamic behaviors. Furthermore, it gave excellent content uniformity. Thus, this DPI using the modified RS01 device would be recommended as a candidate for FP and SX-loaded pharmaceutical DPI products. [ABSTRACT FROM AUTHOR]

Salmeterol (SAL) is a long-acting β2-adrenergic agonist, which is widely used in the therapy of asthma. The aim of this study was to investigate the pharmacokinetics (PK) of inhaled salmeterol in asthma patients using two different dry powder inhalers. This analysis was based on data from 45 subjects who participated in a two-sequence, four-period crossover bioequivalence (BE) study after single administration of the test (T) and reference (R) products. In order to mimic more closely the real treatment conditions, activated charcoal was not co-administered. Plasma concentration-time (C-t) data were initially analysed using classic non-compartmental PK approaches, while the main objective of the study was to apply population PK modeling. The relative fraction of the dose absorbed via the lungs (RL) was set as a parameter in the structural model. The plasma C-t profiles of salmeterol showed a biphasic time course indicating a parallel pulmonary and gastrointestinal (GI) absorption. A two-compartment disposition model with first order absorption from the GI and very rapid absorption from lungs (like an i.v. bolus) was found to describe successfully the C-t profiles of salmeterol. The estimated RL value was 13% suggesting a high gut deposition of inhaled salmeterol. Women were found to exert less capability to eliminate salmeterol than men, while body weight (in allometric form) was found to be an important covariate on the peripheral volume of distribution. [ABSTRACT FROM AUTHOR]

Single crystals of salmeterol xinafoate (form I), prepared from slow cooled supersaturated propan-2-ol solutions, crystallize in a triclinic P 1 ¯ symmetry with 2 closely related independent salt pairs within the asymmetric unit, with an approximately double-unit cell volume compared with the previously published crystal structure. Synthonic analysis of the bulk intermolecular packing confirms the similarity in packing energetics between the 2 salt pairs. The strongest synthons, as expected, are dominated by coulombic interactions. Morphologic prediction reveals a plate-like morphology, dominated by the {001}, {010}, and {100} surfaces, consistent with experimentally grown crystals. Although surface chemistry of the slow-growing {001} face comprises large sterically hindering phenyl groups, although weaker coulombic interactions still prevail from the alcohol group present on the phenyl and hydroxymethyl groups. The surface chemistry of the faster growing {010} and {100} faces are dominated by the significantly stronger cation/anion interactions occurring between the carboxylate and protonated secondary ammonium ion groups. The importance of understanding the cohesive and adhesive nature of the crystal surfaces of an active pharmaceutical ingredient, with respect to their interaction with other active pharmaceutical ingredient crystals and how that may affect formulation design, is highlighted. [ABSTRACT FROM AUTHOR]

Asthma is one of the most common respiratory diseases that can be efficiently managed through combined treatment of fluticasone propionate (FP) and salmeterol xinafoate (SX). In this study, we challenged the use of both spray drying and mixing techniques in sequential combination of lactose or mannitol with FP and SX as two steps in development of inhalable powder formulation of the drugs. Leucine was used as a dispersibility enhancer. The formulations were optimized using the Design-Expert software. The effects of three independent variables namely the type of carrier, percentage of spray-dried carrier and the amount of leucine were investigated on in vitro deposition. The results showed that the maximum fine particle fraction (FPF) and the minimum particle size was belonged to formulation in which the percentage of leucine was 20% with respect to the total solid content and 50% of mannitol was used during spray drying, while the remaining 50% of it was applied in the physical mixing process. This study showed that not only the choice of carrier and additives for every drug combination, but also an optimized ratios of them during both spray drying and physical mixing can be crucial in developing suitable inhalable dry powder formulations. [ABSTRACT FROM AUTHOR]

Background: Chromatographic methods have been used for the simultaneous determination of salmeterol (SMT) and fluticasone (FLU). The methods take a lot of analysis time, need sample pre-treatment and large amounts of solvents, and are costly., Objective: The aim of this paper was to propose a simple, quick, and low-cost method for the determination of SMT and FLU using a time series neural network and multivariate calibration methods, including partial least-squares (PLS) and principal component regression (PCR)., Methods: The simultaneous spectrophotometric determination of SMT and FLU in binary mixtures and anti-asthma spray was performed by applying multivariate calibration methods and an intelligent approach., Results: The coefficient of determination (R2) of the time series neural network was obtained: 1 and 0.9997 for SMT and FLU, respectively. The mean recovery of PLS was found to be 99.29% and 99.84% for SMT and FLU, respectively. Also, the mean recovery related to the PCR method was 102.05% and 103.72% for SMT and FLU, respectively., Conclusion: The inhalation spray was assessed using HPLC and the results were compared with chemometrics methods via an analysis of variance (ANOVA) test., Highlights: Intelligent and multivariate calibration methods were proposed. Simultaneous spectrophotometric determination of salmeterol and fluticasone was studied in an anti-asthma spray. HPLC as a reference method was performed and compared with chemometrics methods. Rapid, simple, low-cost, and accurate are the benefits of the proposed approaches., (© The Author(s) 2023. Published by Oxford University Press on behalf of AOAC INTERNATIONAL. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

A new simple, accurate, precise, rapid and economical method was developed for the simultaneous determination of Salmeterol xinafoate and Fluticasone propionate in their binary mixture in bulk powder and Seritide diskus® inhalation. The new method depends on new calculations using the mixture’s absorbance at 225 and 256.5 nm where the absorptivity of Salmeterol xinafoate is double the absorptivity of Fluticasone propionate, while the content of Salmeterol xinafoate was determined by measuring the absolute value of the first derivative ultraviolet curves at 352 nm, without interference from Fluticasone propionate. The proposed method was validated and the results obtained by adopting the proposed method were statistically analyzed and compared with those obtained by reported methods.

This study was to evaluate the clinical efficacy and safety of fluticasone/ salmeterol inhalation powder plus Huaiqihuang Granules for children with cough variant asthma (CVA). From June 2019 to May 2021, 60 children with CVA were hospitalized to the Pediatrics Department of Cangzhou Central Hospital and randomized to the observation (fluticasone/salmeterol inhalation powder plus huaiqihuang granules) and control group (fluticasone/salmeterol inhalation powder) using the random number table method. The outcome measures include clinical efficacy, forced vital capacity (FVC), forced expiratory volume per second (FEV1), peak expiratory flow (PEF), FeNO, high-sensitivity C-reactive protein (hs-CRP), interleukin-17 (IL-17) and IL-23, airway anatomical indicators and T lymphocyte subsets levels. Both groups exhibited remarkable improvements in FVC, FEV1, PEF and FeNO and hs-CRP, IL-17 and IL-23, with higher FVC, FEV1 and PEF and lower FeNO, hs-CRP, IL-17 and IL-23 in the observation group (all P<0.05). Significantly higher levels of CD4+ and CD4+/CD8+ were observed in the observation group versus control group, but lower airway wall thickness, basement membrane thickness, total airway wall area and CD8+ in the observation group (all P<0.05). Fluticasone/salmeterol inhalation powder plus Huaiqihuang Granules improves lung function, FeNO and airway inflammation in children with CVA and boosts cellular and humoral immune function.

Background: The effectiveness of a fix-dose salmeterol/fluticasone combination therapy in asthma was previously shown for the original product. The study aim was to evaluate the clinical effectiveness and safety of a second entry DPI - dry powder inhaler (Salflumix Easyhaler) in patients with asthma in everyday clinical practice., Patients and Methods: This multicenter Investigator-Initiated Study that enrolled 2,037 adult outpatients with asthma treated with Salflumix Easyhaler, was conducted by 220 pulmonologists across Poland. Asthma control was assessed during 3 visits with 6 ± 2 weeks intervals based on the Asthma Control Test (ACT). In addition, patient Satisfaction with Asthma Treatment Questionnaire (SATQ) and adherence and adverse events (AEs) were monitored., Results: During the observation (86 ± 30 days) the percentage of patients with controlled asthma (ACT 20-25 pts) increased from 35.5% at the first visit to 86.5% at the third visit ( p  < 0.001). In the subgroup analysis, there were more patients not obtaining asthma control among patients that switched from the treatment with other devices than in naive ones. Global SATQ scores increased from 5.8 ± 0.7 to 6.2 ± 0.6 during the observation. Patients' satisfaction with the use of the Salflumix Easyhaler was high. Adherence exceeded 95%. Eight AEs were reported., Conclusions: Salflumix Easyhaler is highly effective and well-tolerated by naïve patients with asthma and those switching from another device. In general, patients show good compliance with medical product and are satisfied with the use of this new device, and not reporting difficulties and errors related to its' use. Their physicians' overall perception of Salflumix Easyhaler use is very positive.

The crystal structure of salmeterol xinafoate has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Salmeterol xinafoate crystallizes in space group P−1 (#2) with a = 9.173 89(13), b = 9.483 79(14), c = 21.3666(4) Å, α = 82.2646(13), β = 85.2531(12), γ = 62.1565(11)°, V = 1628.37(5) Å3, and Z = 2. Key to the structure solution was linking the two fragments by a Li atom along the expected N–H···O hydrogen bond. The salmeterol cation and xinafoate anion are linked by N–H···O and O–H···O hydrogen bonds, interactions which cause the salmeterol to adjust its conformation. The hydrogen bonds result in complex chains along the b-axis. The powder pattern is included in the Powder Diffraction File™ as entry 00-065-1430. [ABSTRACT FROM AUTHOR]

Co-administration of an inhaled corticosteroid and long acting beta agonist for chronic obstructive pulmonary disease has reduced mortality compared to either drug alone. This combination reduces exacerbations, hospitalization, emergency department visits and health care costs. A novel fixed-dose combination of the long acting beta-2 agonist salmeterol xinafoate (SX) and the corticosteroid mometasone furoate (MF) were prepared in a composite particle formulation as brittle matrix powder (BMP) and investigated for suitability as an inhaled combination product. In this study, BMP fixed dose combinations of SX and MF with or without stabilizing excipients (lactose, mannitol, glycine and trehalose) were prepared and characterized with respect to their thermal properties, morphology, aerodynamic performance and physical stability. BMP combination formulations of SX and MF exhibited improved aerodynamic properties when delivered by dry powder inhalation as compared to the micronized blends of the same substances. Aerodynamic evaluation was carried out by next generation pharmaceutical impactor (NGI) with a marketed DPI device. Results demonstrated that co-deposition occurred when SX and MF were formulated together as composite particles in a BMP, while physical blends resulted in inconsistent deposition and dose uniformity. As a result of the bottom-up particle engineering approach, combination BMP formulations allow for dual API composite formulations to be dispersed as aerosolized particles. Aerosolized BMP combination formulations resulted in delivered dose uniformity and co-deposition of each API. Further, an excipient-free formulation, BMP SXMF, delivered approximately 50% of the loaded dose in the respirable range and demonstrated stability at ambient conditions for 6 months. Single dose 24-h pharmacokinetic studies in rats demonstrated that lung tissue deposition and blood circulation (AUC 0–24h ) of two APIs were higher for the BMP combination group exhibiting a significantly higher lung concentration of drugs than for the crystalline physical blend. While high system drug levels are generally undesirable in lung targeted therapies, high blood levels in this rodent study could be indicative of increased pulmonary tissue exposure using BMP formulations. [ABSTRACT FROM AUTHOR]

Salmeterol xinafoate is a potent and a long-acting β2-adrenoceptor agonist. It is prescribed for the treatment of severe persistent asthma and chronic obstructive pulmonary disease. Different methods were used to prepare (R)-(-)-salmeterol such as: mixing a sample of 4-benzyloxy-3-hydroxymethyl-ω-bromoacetophenone with sodium lauryl sulfate and the mixture was added to the microbial culture of Rhodotorula rubra, treatment of p-hydroxyacetophenone with Eschenmoser's salt and carbonate exchange resin followed by a sequence of supported reagents and scavenging agents or via Rh-catalyzed asymmetric transfer hydrogenation. The enantioselective synthesis of (S)-salmeterol was achieved via asymmetric reduction of the azidoketone 4 by Pichia angusta yeast. Physical characteristics of salmeterol xinafoate were confirmed via: X-ray powder diffraction pattern, thermal analysis and UV, vibrational, nuclear magnetic resonance, and mass spectroscopical data. Initial improvement in asthma control may occur within 30 min following oral inhalation of salmeterol in fixed combination with fluticasone propionate. Clinically important improvements are maintained for up to 12 h in most patients. It is extensively metabolized in the liver by hydroxylation, thus increased plasma concentrations may occur in patients with hepatic impairment. [ABSTRACT FROM AUTHOR]

Simple, accurate, precise and fully validated analytical methods for the simultaneous determination of salmeterol xinafoate and fluticasone propionate in combined dosage forms have been developed. These drugs were exposed to thermal, photolytic, hydrolytic and oxidative stress conditions, and the stressed samples were detected by the proposed method. Additionally, p K values of three ionizable drugs (salmeterol xinafoate, fluticasone propionate and thioridazine) were determined using by the dependence of the retention factor on pH of the mobile phase. The effect of the mobile phase composition on the ionization constant was studied by measuring the p K in different acetonitrile-water mixtures, ranging between 50 and 65% (v/v) using LC-UV method. [ABSTRACT FROM AUTHOR]

Regulatory science for generic dry powder inhalers (DPIs) in the United States (U.S.) has evolved over the last decade. In 2013, the U.S. Food and Drug Administration (FDA) published the draft product-specific guidance (PSG) for fluticasone propionate and salmeterol xinafoate inhalation powder. This was the first PSG for a DPI available in the U.S., which provided details on a weight-of-evidence approach for establishing bioequivalence (BE). A variety of research activities including in vivo and in vitro studies were used to support these recommendations, which have led to the first approval of a generic DPI in the U.S. for fluticasone propionate and salmeterol xinafoate inhalation powder in January of 2019. This review describes the scientific and regulatory activities that have been initiated by FDA to support the current BE recommendations for DPIs that led to the first generic DPI approvals, as well as research with novel in vitro and in silico methods that may potentially facilitate generic DPI development and approval., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier B.V.)

[Display omitted] • Charge transfer reaction used for colorimetric determination of two beta 2 agonists. • DDQ and chloranilic acid reagents were used in this study. • Proposed methods used for determination of selected drugs in dosage forms. • Proposed methods used for determination of selected drugs in spiked plasma. Beta 2 agonists are well known for their use in the treatment of asthma and COPD however in the last few years new indications of beta 2 agonist appeared like reduction of local fats and treatment of preterm labour which required the formulation of new dosage forms and administration strategies. The new developments require accurate, economic and feasible methods the determination of these drugs to facilitate testing the newly introduced dosage forms and to study the pharmacokinetics and pharmacodynamics regarding the modern uses. In this study two rapid, sensitive and economic colorimetric methods for the determination of salmeterol xinafoate and salbutamol in pharmaceutical dosage forms and spiked plasma were developed and validated. The developed methods depends on the optimized reaction of the studied drugs with two charge transfer reagents, 2,3-dochloro-5,6-dicyano-1,4-benzoquonone (DDQ) and chloranilic acid (CA) to produce coloured complexes measured at 460 and 529 nm for DDQ and CA respectively. The developed methods showed high accuracy of 99.52 ± 1.108, 101.03 ± 0.389, 100.04 ± 1.520 and 100.3 ± 0.951 for salmetrol xinafoate and salbutamol with DDQ and CA respectively. The proposed methods were successfully used for the determination of the studied drugs in their dosage forms and spiked plasma with high accuracy and precision and the results were compared to reported methods. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to investigate the use of N-acetylglucosamine (NAG) to accelerate drug release from a lectin-modified carrier. A wheat germ agglutinin (WGA)-anchored salmeterol xinafoate (SalX)-loaded nanoparticles-in-microparticles system (NiMS) was prepared with an ionotropic gelation technique combined with a spray drying method. The formulated microparticles were spherical, with diameters ranging mainly from 2 to 8μm; the drug entrapment efficiency was >70% (w/w), and the loading capacity was approximately 8% (w/w). Drug release from WGA-SalX-NiMS, within the first 4h, was approximately 30% less than that from SalX-NiMS, indicating an effect of lectin-modification to retard drug release from the NiMS. Due to “sugar–lectin” interactions, drug release from WGA-SalX-NiMS was substantially increased after the addition of NAG to the release medium. However, no significant influence of NAG was observed on the drug release profile of SalX-NiMS without WGA anchorage. The characteristics of NAG–WGA interaction may provide valuable insights into the “triggering-effects” of specific sugars on drug release from lectin-anchored carriers. These results suggest that it is possible to control drug release from a lectin-anchored drug delivery system using a specific sugar, and that the designed novel WGA-SalX-NiMS may be a suitable formulation for chronotherapy of asthma. [Copyright &y& Elsevier]

Salmeterol is a long acting beta2-agonist (LABA) used widely for the treatment of airways disease. There is evidence that beta2-agonists, including salmeterol, have the potential for performance enhancing effects when delivered at supratherapeutic doses. For this reason, all beta2-agonists are currently on the Prohibited List issued by the World Anti-Doping Agency (WADA), regardless of dosing route with some exemptions for inhaled salbutamol, formoterol, and salmeterol when used at therapeutic inhaled doses. For 2020, salmeterol use is permitted up to a therapeutic dosing threshold of 200 μg daily, but unlike salbutamol and formoterol, there is an anomaly; currently there is no urine threshold to control for supratherapeutic dosing beyond this dosing threshold. Salmeterol, however, is reportable as an adverse analytical finding (AAF) at levels above 10 ng/mL. Complicating matters is that following inhalation, salmeterol parent drug is present at relatively low levels compared with other beta2-agonists due to rapid metabolism to the metabolite, alpha-hydroxysalmeterol, which is typically present at higher levels than the parent drug. Moreover, peak parent drug levels following permitted therapeutic dosing are below the minimum required performance level (MRPL) of 10 ng/mL for salmeterol (50% of the MRPL that analytical laboratories are required to meet for non-threshold beta2-agonists), hence the presence of salmeterol may be unreported. For consistency, a urine threshold should be introduced for salmeterol as a matter of priority, to balance the needs of athletes who use salmeterol therapeutically up to the agreed dosing threshold, with the need to control supratherapeutic dosing for doping intentions and athlete harm minimization., (© 2020 John Wiley & Sons, Ltd.)

Background: Wixela Inhub (trademarks of Viatris, Inc.) is a dry powder inhaler (DPI) that delivers a fixed-dose combination of fluticasone propionate and salmeterol and is approved as a generic equivalent to Advair Diskus (trademarks of GlaxoSmithKline plc) for the treatment of asthma and chronic obstructive pulmonary disease (COPD). The dosing performance of DPIs is dependent on the patient's inspiratory capability, which may be impacted in disease populations such as those with severe COPD. The objective of this study was to evaluate the in vitro dose delivery of fluticasone propionate and salmeterol from the Inhub inhaler with in vivo inhalation profiles of severe COPD patients, using two types of breathing simulator with different modes of operation. Materials and Methods: Two breathing simulators (Si-Plan and Copley BRS3100) were used with United States Pharmacopoeia (USP) <601> apparatus 5 (Next Generation Impactor and accessories) to measure the total emitted dose and fine particle mass of fluticasone propionate and salmeterol for Wixela Inhub (250/50 mcg) using 13 severe COPD patient inhalation profiles. Results: Wixela Inhub demonstrated low flow dependency across the range of COPD patient profiles tested (peak inspiratory flow rate 60.8-84.9 L minute -1 ), when assessed by total emitted dose and fine particle mass. The results were similar to literature results reported for fluticasone propionate from the Diskus inhaler, tested using a proprietary breathing simulator and Andersen Cascade Impactor. Comparison between the breathing simulators showed no significant difference in fluticasone propionate results, but a small difference was observed between the breathing simulators for salmeterol total emitted dose and fine particle mass. Conclusions: This study demonstrates that severe COPD patients are likely to achieve a consistent inhaled dose from Wixela Inhub, with low flow dependency observed within this patient population. In addition, both breathing simulators, which differ significantly in design, produced similar results for fluticasone propionate, but yielded slightly (but statistically significant) different results for salmeterol.

Abstract: A new simple, accurate, precise, rapid and economical method was developed for the simultaneous determination of Salmeterol xinafoate and Fluticasone propionate in their binary mixture in bulk powder and Seritide diskus® inhalation. The new method depends on new calculations using the mixture’s absorbance at 225 and 256.5nm where the absorptivity of Salmeterol xinafoate is double the absorptivity of Fluticasone propionate, while the content of Salmeterol xinafoate was determined by measuring the absolute value of the first derivative ultraviolet curves at 352nm, without interference from Fluticasone propionate. The proposed method was validated and the results obtained by adopting the proposed method were statistically analyzed and compared with those obtained by reported methods. [Copyright &y& Elsevier]

Abstract: Inhalation particles can be produced by various techniques such as milling, controlled crystallisation and spray-drying, but current methods cannot, to-date, precisely control the aerodynamic size distribution of produced powders. The aim of this study was to develop and validate a novel preparative technique whereby the efficient and reproducible aerodynamic fractionation of drug and excipient powders could be achieved. Salmeterol xinafoate (SX), fluticasone propionate (FP) and fine α-lactose monohydrate (FL) were chosen as model compounds. Powders were aerosolised using a dry powder feeder into a Next Generation Impactor operated at 60Lmin−1. Powders deposited on NGI stages were then collected and analysed. The fractionation process was successful for all powders producing significant linear correlations between the pre-set aerodynamic cut-off limits and geometric size measurements. For each of SX, FP and FL, sufficient powder quantities were recovered from NGI stages 1–6 producing six fractions with sequential aerodynamic and geometric particle size distributions. The fractionation technique was efficient and reproducible for all powders studied. The method can be equally applied to various drugs and excipients regardless of their previous production/processing history. Therefore, the aerodynamic fractionation technique may be used to compare and contrast samples produced by different processes. [Copyright &y& Elsevier]

A novel flow through (FT) diffusion cell for assessing the permeability of compounds across the buccal mucosa was designed. Porcine buccal mucosa was mounted between two chambers with flow through capacity in both the donor and receptor chambers. The permeability of caffeine (CAF), triamcinolone acetonide (TAC), and estradiol (E2) was determined over 4 h and flux values were compared to those obtained using a modified Ussing chamber (MUC). No significant differences in the flux of each probe compound were observed using either the MUC or the novel FT cell. The design of the FT cell allowed for monitoring appearance of receptor solution within the donor chamber during the initial equilibration period, allowing for visual inspection of tissue integrity. These permeability studies demonstrate that this FT cell is a suitable alternative model for assessing drug permeability across the buccal mucosa, without the limitations associated with the static MUC. This novel model was then utilized to determine whether salmeterol xinafoate (SX) could permeate the buccal mucosa at concentrations expected in the oral cavity following inhalation. Concentration-dependent studies demonstrated that SX permeates the buccal mucosa via passive diffusion and that oral mucosal absorption may contribute significantly to the overall systemic exposure of inhaled SX. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:4577–4588, 2009 [ABSTRACT FROM AUTHOR]

Abstract: This study investigated the relationship between surface energy of micronized lactose, coarse lactose and salmeterol xinafoate and dispersibility from a mixture after storage at 75% RH. Surface energies, dispersibility, morphology, and the presence of amorphous domains were determined by inverse gas chromatography, twin stage impinger, scanning electron microscope and dynamic vapour sorption, respectively. The fine particle fraction of mixture decreased significantly in 4 weeks (P <0.05), reaching a static level in 3 months. Amorphous content was not detected in the micronized lactose, coarse lactose and salmeterol xinafoate. After conditioning stored samples at 75% RH for 2h, dispersive surface energy of both micronized and coarse lactose significantly decreased (P <0.05), while the polar surface energy of all significantly increased (P <0.05) resulting in significant increase in total surface energy after storage. After conditioning stored samples at 0% RH for 2h, no significant difference was observed in any surface energy parameter. This study concluded that the total surface energy increased during storage at high RH due to the adhered surface moisture. The mechanism of decreased dispersibility was related to increased capillary/solid bridging interactions and to possible increased interaction of contiguous particles due to increased polar surface energy. [Copyright &y& Elsevier]

Abstract: Purpose: This study investigated changes in agglomeration and the mechanism of dispersibility decrease of salmeterol xinafoate (SX) from SX–lactose mixtures for inhalation after storage at 75% RH for 3 months. Methods: The dispersibility, PSD and in situ PSD of aerosol plumes of SX alone and SX–coarse lactose (CL) mixtures containing 0, 5, 10 and 20% micronized lactose (ML) before and after storage were determined by a Next Generation Impactor (NGI), a Mastersizer 2000 and a Spraytec, respectively. Results: The PSD of ML increased after storage at 75% RH, but dispersibility of SX using the stored ML increased. After storage, the %SX of the mixture containing 20% ML (M20F) significantly increased (P <0.05) in the throat and mouthpiece, preseparator and stage 1 of NGI, while it significantly decreased in the remaining stages (P <0.05). In situ analysis of aerosol plumes of M20F supported this result with an increased presence of particles of 4–25μm and a decreased respirable particle distribution of <4μm after storage. Conclusions: The decreased dispersibility of M20F after storage was due to the formation of less dispersible agglomerates, probably occurring through enhanced capillary interaction and/or solid bridging of ML, entrapping and preventing the release of SX particles. [Copyright &y& Elsevier]

The in vitro dispersion of salmeterol xinafoate (SX) alone and four SX (2.5%)–coarse lactose (CL) mixtures containing 0%, 5%, 10% and 20% micronised lactose (ML) was monitored during 18-month storage at 33%, 55% and 75% relative humidity (RH) using a twin stage impinger. The surface moisture was monitored over 2 months by thermo gravimetric analysis. The morphology was determined by scanning electron microscopy. An aerosizer was used to compare the agglomerate strengths of formulations before and after storage at 75% RH. Upon storage, no significant difference occurred in fine particle fraction (FPF) of any formulation at 33% and 55% RH. Within 8 weeks, the FPF of mixture containing 20% ML (M20F) significantly decreased from 11.3% to 7.7% at 75% RH (p = 0.008) and to 4.9% at 95% RH (p = 0.001). The calculated capillary forces were greater for ML–ML contact than other particle interactions and the propensity of ML–ML contacts was higher in M20F. The agglomerate strength of M20F significantly increased after storage. The study concluded that the critical factors for decreased dispersion of SX formulations were RH of 75% or greater and the presence of high concentrations of ML due to capillary forces and/or solid bridge formation of ML leading to increased agglomerate strength. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:1015–1027, 2009 [ABSTRACT FROM AUTHOR]

Abstract: The purpose of this study was to determine and understand the effect of the polydispersity of fine lactose (FL) on the dispersion of salmeterol xinafoate (SX) from SX-coarse lactose mixtures for inhalation. SX mixtures were prepared using validated laboratory mixing. The in vitro deposition of SX was measured using a twin-stage impinger and SX analysed using high performance liquid chromatography. The distributions of FL included both cohesive to non-cohesive fractions. Reduction in the span of the FL distributions with a volume median diameters (VMD) about 7μm showed no significant difference in the fine particle fraction (FPF) of SX (P >0.05), while reduced FPF of SX was observed with the reduction in the span of FL with VMD about 19 and 32μm, respectively. When the FPF of SX was correlated with the concentration of FL in specific fractions, there was a marked, linear increase in FPF for increasing concentrations of FL in the 5–10μm fraction; however, all other fractions showed no significant increase in FPF. The study reflects the importance of lactose polydispersity in drug dispersion. Specific size fractions of cohesive FL enhance dispersion, while non-cohesive fractions of FL act as secondary carriers and decrease dispersion performance. [Copyright &y& Elsevier]

Direct crystallization of active pharmaceutical ingredient (API) particles in the inhalable size range of 1–6 µm may overcome surface energization resulting from micronization. The aerosolization of fluticasone propionate (FP) and salmeterol xinafoate (SX) microcrystals produced by aqueous crystallization from poly(ethylene glycol) solutions was investigated using a twin stage impinger following blending with lactose. Fine particle fractions from SX formulations ranged from 15.98 ± 2.20% from SX crystallized from PEG 6000 to 26.26 ± 1.51% for SX crystallized from PEG 400. The FPF of microcrystal formulations increased as the particle size of microcrystals was increased. The aerosolization of SX from DPI blends was equivalent for the microcrystals and the micronized material. FP microcrystals, which had a needlelike morphology, produced similar FPFs (PEG 400: 17.15 ± 0.68% and PEG 6000: 15.46 ± 0.97%) to micronized FP (mFP; 14.21 ± 0.54). The highest FPF (25.66 ± 1.51%) resulted from the formulation of FP microcrystals with the largest median diameter (FP PEG 400B: 6.14 ± 0.17 µm). Microcrystallization of SX and FP from PEG solvents offers the potential for improving control of particulate solid state properties and was shown to represent a viable alternative to micronization for the production of particles for inclusion in dry powder inhalation formulations. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:503–515, 2009 [ABSTRACT FROM AUTHOR]