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Ambroxol (AMB) is a commonly used bromine-containing organic compound in medical applications and has been frequently found in water environments, which might pose risks of forming brominated disinfection by-products (Br-DBPs) in water treatment systems. The degradation kinetics as well as the degradation mechanism of AMB in the UV/chloramine process were investigated in this study. It was determined that reactive chlorine species (RCS) and the reactive nitrogen species (RNS) were the dominant free radicals for AMB degradation. Debromination occurred mainly in the initial stage of the degradation process, with a debromination rate of 34.5% at 10 min. Four possible degradation pathways of AMB were proposed based on liquid chromatography mass spectrometry (LC-MS) analysis as well as density functional theory (DFT) calculations, meanwhile the ECOSAR model was used to predict the toxicity risk of AMB and its degradation intermediates. Furthermore, after assessing the formation of DBPs during the UV/chloramine pre-oxidation process and conducting a toxicity risk analysis based on the results, it has been verified that this method can effectively remove AMB while reducing the formation potential of DBPs in the water environment. This suggests that the UV/chloramine process shows promise for treating bromine-containing organic compounds in real-world water treatment applications., 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 Ltd. All rights reserved.)

Inhalation injuries arising from exposure to toxic gases or smoke in fires or industrial accidents pose grave risks and significant respiratory complications. The limited efficacy of current treatment strategies stems from challenges in delivering therapeutic agents across the mucus barrier to the damaged trachea and bronchus. This research explores the reparative potential and underlying mechanisms of sputum-penetrable magnetic nanoparticles (MNPs) coated with poly( N -isopropylacrylamide) (PNIPAM), combined with polyethylene glycol (PEG), and loaded with ambroxol hydrochloride (AH) (MNPs@PNIPAM-AH@PEG) as an innovative therapeutic approach for inhalation injuries. The PNIPAM coating, a thermo-responsive polymer, aims to enhance targeted drug release under an external stimulus. The PEG component is designed to mitigate hydrophobic repulsion and electrostatic forces, facilitating nanoagent penetration of the mucus barrier-an obstacle in inhalation injury treatment. PEG's hydrophilicity, combined with the magnetically attracted NPs, enables deep penetration through the mucus layer adhering to the mucus epithelium. Thermal effects break the outer thermal shell of MNPs, accelerating drug release, resolving sputum, and reducing inflammation. The results showed improved therapeutic impact by significantly reducing inflammation, enhancing mucociliary clearance, and promoting tissue repair. Moreover, the MNPs@PNIPAM-AH@PEG NPs showed good biocompatibility and biosafety both in vitro and in vivo . This research underscores the potential of MNPs@PNIPAM-AH@PEG NPs as a novel therapeutic strategy for inhalation injuries, paving the way for innovative treatments in emergency medicine and respiratory care.

The GBA1 gene encodes for the lysosomal enzyme glucocerebrosidase (GCase), which maintains glycosphingolipid homeostasis and regulates the autophagy process. Genomic variants of GBA1 are associated with Goucher disease; however, several heterozygous variants of GBA (E326K, T369M, N370S, L444P) are frequent high-risk factors for Parkinson's disease (PD). The underlying mechanism of these variants has been revealed through functional and patient-centered research, but the structural and dynamical aspects of these variants have not yet been thoroughly investigated. In the current study, we used a thorough computational method to pinpoint the structural changes that GBA underwent because of genomic variants and drug binding mechanisms. According to our findings, PD-linked nsSNP variants of GBA showed structural variation and abnormal dynamics when compared to wild-typ. The docking analysis demonstrated that the mutants E326K, N370S, and L444P have higher binding affinities for Ambroxol. Root means square deviation (RMSD), Root mean square fluctuation analysis (RMSF), and MM-GBSA analysis confirmed that the Ambroxol are more stable in the binding site of N370S and L444P, and that their binding affinities are stronger as compared to the wild-type and T369M variants of GBA. The evaluation of hydrogen bonds and the calculation of the free binding energy provided additional evidence in favor of this conclusion. When docked with Ambroxol, GBA demonstrated an increase in binding affinity and catalytic activity. Understanding the therapeutic efficacy and potential against the aforementioned changes in the GBA will be beneficial in order to use more efficient methods for developing novel drugs.

Bromhexine and ambroxol are among the mucolytic drugs most widely used to treat acute and chronic respiratory diseases. Entering the municipal wastewater and undergoing transformations during disinfection with active chlorine, these compounds can produce nitrogen- and bromine-containing disinfection by-products (DBPs) that are dangerous for aquatic ecosystems. In the present study, primary and deep degradation products of ambroxol and bromhexine obtained in model aquatic chlorination experiments were studied via the combination of high-performance liquid and gas chromatography with high-resolution mass spectrometry. It was shown that at the initial stages, the reactions of cyclization, hydroxylation, chlorination, electrophilic ipso -substitution of bromine atoms with chlorine, and oxidative N-dealkylation occur. Along with known metabolites, a number of novel primary DBPs were tentatively identified based on their elemental compositions and tandem mass spectra. Deep degradation of bromhexine and ambroxol gives twenty-four identified volatile and semi-volatile compounds of six classes, among which trihalomethanes account for more than 50%. The specific class of bromhexine- and ambroxol-related DBPs are bromine-containing haloanilines. Seven of them, including methoxy derivatives, were first discovered in the present study. One more novel class of DBPs associated with bromhexine and ambroxol is represented by halogenated indazoles formed through dealkylation of the primary transformation products containing pyrazoline or tetrahydropyrimidine cycle in their structure., Competing Interests: The authors declare no conflicts of interest.

This study aimed to investigate the antimicrobial and biological properties of Ambroxol associated with glycerin (GLI), propylene glycol (PG), and polyethylene glycol (PEG) as a possible vehicle for an experimental tricalcium silicate sealer, with the intention of developing a new biomaterial. Mouse undifferentiated dental pulp cells (OD-21) were cultured, and the effects of different association on cell proliferation and inflammatory cytokine production were investigated. Antimicrobial adhesion of Enterococcus faecalis to setting sealers at 2 h was evaluated. Polyethylene tubes containing experimental sealers and empty tubes were implanted into dorsal connective tissues of 12 male 3- to 4-months-old Wistar rats (250-280 g). After 7 and 30 days, the tubes were removed and processed for histological and immunohistochemical analyses. ANOVA followed by Bonferroni correction and ANOVA followed by Tukey test was used for parametric data and Kruskal-Wallis followed by Dunn for nonparametric (p < 0.05). Cell proliferation was dose-dependent, since all association were cytotoxic at higher concentrations; however, Ambroxol-PEG showed significantly higher cytotoxicity than other association (p < 0.05). In addition, irrespective of the association, no cytokine production was observed in vitro. Ambroxol-GLI reduced bacterial viability, whereas Ambroxol-PEG increased (p < 0.05). Histological examination showed no significant difference in the inflammatory response (p > 0.05) and mineralization ability in all association. Additionally, IL-1β and TNF-α were upregulated on Ambroxol-PEG in relation to Control at 07 days (p < 0.05). Ambroxol-GLI was the best vehicle for experimental tricalcium silicate sealer, as it promoted an increase in antimicrobial activity without altering the inflammatory response or mineralization ability., (© 2021. The Author(s).)

Recently, a combination of cilostazol and ambroxol has been used in the clinical treatment of stroke-associated pneumonia (SAP). However, the pharmacokinetic drug-drug interaction (DDI) of cilostazol and ambroxol has not been reported. In this paper, a rapid, reproducible and sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) method for simultaneous determination of cilostazol and ambroxol in Sprague-Dawley (SD) rat plasma was established and validated for the first time. Domperidone was used as the internal standard (IS) and one-step liquid-liquid extraction (LLE) method was used to extract analytes and IS from plasma samples with methyl tert-butyl ether as extractant. A rapid chromatographic separation within 4.8 min was carried on an Ultimate ® XB-C 18 column with a mobile phase consisting of methanol-acetonitrile-formic acid (0.1%) aqueous solution (90:2:8, v/v/v) at a flow rate of 500 μL/min. The quantitative detection of the analytes and IS were performed on a positive electrospray ionization mode (ESI), and scanned by multi-reaction monitoring (MRM) with the ion transitions m/z 370.3 → m/z 288.2 for cilostazol, m/z 378.8 → m/z 263.8 for ambroxol and m/z 426.2 → m/z 175.1 for domperidone (IS), respectively. It had good linearity in the range of 5.0-1000 ng/mL for cilostazol and 1.0-200 ng/mL for ambroxol in rat plasma. The methodology was fully validated with selectivity, linearity, lower limits of quantification, precision, accuracy, extraction recovery, matrix effect, stability and carry-over effect. The validated data have met the determination requirements of biological samples in FDA guideline. The method was successfully applied to the pharmacokinetics and DDI study of cilostazol and ambroxol in male SD rats. The current study found that the interaction between cilostazol and ambroxol may be caused by CYP3A4 and the pharmacological properties of cilostazol, which may be helpful for therapeutic drug monitoring, clinical dose reference and provide a valuable tool for drug-drug interactions., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Supramolecular encapsulation by cucurbit[7]uril (CB[7]) was recently demonstrated to provide a simple and efficient method for antibacterial activity regulation of antibiotics. In this work, CB[7] was shown to form binary host-guest complex with ambroxol hydrochloride (ABX), a clinical mucokinetic and expectorant drug, which was reported to exhibit certain antibacterial activity. 1 H NMR titration and isothermal titration calorimetry experiment results suggested that the 4-hydroxyl cyclohexylamine group of ABX was included inside the CB[7] cavity, with a binding constant K a of (6.69±0.11)×10 5  M -1 in phosphate buffered saline (PBS) solution, thermodynamically driven by both enthalpy change (ΔH=-12.2 kJ/mol) and entropy change (TΔS=21.1 kJ/mol). More importantly, ABX's inhibitory activity (MIC 50 ) against bacillary strains towards Pseudomonas aeruginosa and Escherichia coli strains was decreased from (5.11±0.31)×10 -6  M -1 and (2.63±0.34)×10 -5  M -1 to zero upon encapsulation by CB[7], and was subsequently recovered to almost its original activity when a competitive guest, amantadine hydrochloride, for disassembling CB[7]-ABX complex, was added, suggesting that the antibacterial activity of ABX could be readily "turned off/on" upon its complexation and decomplexation with CB[7]., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Two high performance chromatographic methods were developed and validated for the simultaneous determination of Ambroxol, Guaifenesin and Theophylline in pharmaceutical dosage forms and in the presence of Guaiacol and Caffeine as the officially stated impurities. These were a reversed phase liquid and a thin layer chromatographic methods. The liquid chromatographic separation was achieved using Inertsil ODS-3 C 18 column (4.6 mm × 250 mm, 5 μm). Gradient elution was performed using a mixture of solvent A (0.05 M ammonium acetate, pH 3, adjusted with glacial acetic acid) and solvent B (methanol), at a flow rate of 1.0 mL/min. The separated peaks were detected at 260.0 nm. The thin layer chromatography was performed using HPTLC 60 F 254 silica gel plates, mobile phase was consisting of ethyl acetate: methanol: acetic acid (10:0.5:1, v/v/v) and detection was performed at 254.0 nm. Validation of the developed methods was achieved according to International Conference on Harmonization (ICH) guidelines. The proposed methods were fast, accurate, precise, and sensitive. Hence, they could be employed for routine quality control of the ternary mixture in capsule and syrup dosage forms., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In respiratory and genetic disorders such as asthma, chronic obstructive pulmonary disease (COPD), chronic bronchitis and cystic fibrosis (CF), the lungs produce excess mucus, resulting in a thickened mass, which clogs up the airways and reduces airflow. Consequently, breathing becomes more difficult. Medications that break down the structure of mucus will be especially useful in managing the early symptoms of these diseases and preventing their progression into the more severe forms. This work therefore seeks to develop an inhaled mucoactive dry powder formulation that is efficacious on multiple fronts. As an innovative step, sodium chloride was used to tailor the surface architecture of ambroxol hydrochloride particles, such that the resulting angular features on the surfaces contributed to the creation of corrugated particles with enhanced aerodynamicity. The optimized spray-dried powder particles were of respirable-size (d 50 of 2.85 ± 0.15 μm) and moderately corrugated. When the crystalline powder was dispersed via an Aerolizer® inhaler at 60 L/min, it gave a fine particle fraction (FPF) of ~31%, which was a ten-fold improvement over the unmodified species (i.e. ambroxol hydrochloride alone). Tests on artificial sputum medium (ASM) showed that the optimized formulation was potentially useful in liquefying the mucus, which favorably pointed towards the effectiveness of the formulation. In addition, the formulation was also stable to moisture ingress (up to ~60% RH) and had good flowability. Hence, the advent of angular adjuvant sodium chloride particles in a mucoactive formulation conferred a three-fold benefit to the product: (1) Improved aerodynamicity and flowability, (2) Enhanced moisture stability and (3) Synergistic mucolytic properties., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The combination of acebrophylline (ABP), levocetirizine (LCZ) and pranlukast (PRN) is used to treat allergic rhinitis, asthma, hay-fever and other conditions where patients experience difficulty in breathing. This study was carried out with the aim of developing and validating a reverse-phase high-performance liquid chromatographic bioanalytical method to simultaneously quantitate ABP, LCZ and PRN in rat plasma. The objective also includes determination of the pharmacokinetic interaction of these three drugs after administration via the oral route after individual and combination treatment in rat. Optimum resolution between the analytes was observed with a C 18 Kinetex column (250 mm × 4.6 mm × 5 μm). The chromatography was performed in a gradient elution mode with a 1 mL/min flow rate. The calibration curves were linear over the concentration range of 100-1600 ng/mL. The intra- and inter-day precision and accuracy were found to be within acceptable limits as specified in US Food and Drug Administration guideline for bioanalytical method validation. The analytes were stable on the bench-top (8 h), after three freeze-thaw cycles, in the autosampler (8 h) and as a dry extract (-80°C for 48 h). The statistical results of the pharmacokinetic study in Sprague-Dawley rats showed a significant change in pharmacokinetic parameters for PRN upon co-administration of the three drugs., (© 2019 John Wiley & Sons, Ltd.)

Resealed erythrocytes (RSE) are potential, site-specific carrier system for drug delivery with prolonged drug release activity. In this study, erythrocytes obtained from Wistar albino rats were loaded with ambroxol hydrochloride (AH) with the focus to convenience the lung targeting possibility of the carrier erythrocytes. AH loading in erythrocytes using preswell dilution technique with glutaraldehyde (GA) as a cross-linking agent was evaluated and validated. Drug-loaded erythrocyte was characterized in terms of in vitro drug release followed by osmotic fragility study which showed amplified drug entrapment efficiency (DEE) and hemoglobin content values as well. In vivo lung fibrosis study, rats were sensitized to egg albumin by intraperitoneal (i.p.) injection and then inhalation in a whole body inhalation chamber. A sign of inflammation, airway sub-mucosal fibrosis, hypertrophy, and hyperplasia was observed. A series of in vivo studies were carried out to describe the effect of AH-loaded RSE including measurement of cytokines in Bronchoalveolar Lavage (BAL) fluid and histopathology study. AH showed a stepwise reduced level of cytokines in BAL at a different time interval after being injected of AH-loaded RSE. Furthermore, in vivo lung distribution experiments were performed for optimized formulation, and degree of distribution of the drugs inside the targeted organ was found to be satisfactory.

Ambroxol is a pharmacological chaperone (PC) for Gaucher disease that increases lysosomal activity of misfolded β-glucocerebrosidase (GCase) while displaying a safe toxicological profile. In this work, different poly(ε-caprolactone) (PCL)-based systems are developed to regulate the sustained release of small polar drugs in physiological environments. For this purpose, ambroxol is selected as test case since the encapsulation and release of PCs using polymeric scaffolds have not been explored yet. More specifically, ambroxol is successfully loaded in electrospun PCL microfibers, which are subsequently coated with additional PCL layers using dip-coating or spin-coating. The time needed to achieve 80% release of loaded ambroxol increases from ≈15 min for uncoated fibrous scaffolds to 3 days and 1 week for dip-coated and spin-coated systems, respectively. Furthermore, it is proven that the released drug maintains its bioactivity, protecting GCase against induced thermal denaturation., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Background: Trigeminal neuralgia is difficult to treat and shows upregulation of sodium channels. The expectorant ambroxol acts as a strong local anesthetic, about 40 times stronger than lidocaine. It preferentially inhibits the channel subtype Na v 1.8, expressed especially in nociceptive C-fibers. It seemed reasonable to try ambroxol for the treatment with neuropathic facial pain unresponsive to other standard options., Material and Methods: Medical records of patients suffering from classical trigeminal neuralgia (n = 5) and successful pain reduction following topical ambroxol 20% cream in addition to standard treatment are reported., Results: All patients reported pain attacks with pain intensity between 4 and 10 NRS (numeric pain scale). In all cases they could be triggered, 3 patients reported additional spontaneous pain. Attacks were reduced in all 5 patients. Pain reduction achieved following ambroxol 20% cream was 2-8 points (NRS) earliest within 15-30 minutes and lasted for 4-6 hours mostly. This was reproducible in all cases; in one case pain was eliminated after 1 week. No patient reported side effects or skin changes; oral medication was reduced in 2 patients., Conclusion: For the first time, a clinically significant pain relief following topical ambroxol 20% cream in patients with trigeminal neuralgia is reported. In view of the positive side effect profile, topical ambroxol for patients with such a highly impaired quality of life should be investigated further as a matter of urgency., (© 2019 American Headache Society.)

Gaucher's disease (GD) is the most commonly known lysosomal disorder that occurs due to mutations in the β-glucocerebrosidase (GBA) protein. Our previous findings (Thirumal Kumar, Eldous, Mahgoub, George Priya Doss, Zayed, 2018) and other reports concluded that the mutations N370S and L444P are the most significant mutations that could cause disruptions in protein stability and structure. These disruptions lead to protein misfolding and result in a diseased condition. Enzyme Replacement Therapy (ERT) and Pharmacological chaperone therapy (PCT) are currently used to treat GD caused by mutations in the GBA protein. The extreme disparity in cost between ERT and chaperone therapy, shifted the attention toward chaperone therapy. The most common chaperones in the market and trial phases to treat GD are Isofagomine, Miglustat, Eliglustat, NN-DNJ, and Ambroxol. In the era of personalized medicine, it is often necessary to understand the drug likeliness of each chaperone. In this context, the present study utilized molecular docking analysis to understand the interaction behavior of the chaperone toward the native and the two mutants N370S and L444P. The molecular dynamics simulation analyses performed on chaperones (NN-DNJ and Ambroxol) interaction showed that the chaperone NN-DNJ possesses better affinity toward the protein with N370S mutation whereas chaperone Ambroxol showed better activity against both the significant mutations (N370S and L444P). This study is expected to serve as a platform for drug repurposing., (© 2019 Elsevier Inc. All rights reserved.)

Background: Ambroxol relieves cough symptoms based on its secretagogue, anti-inflammatory, anti-oxidant, anti-bacterial, anti-viral, immunomodulatory and local anesthetic effects. The present study was designed to explore differential patient profiles and efficacy against acute respiratory symptoms of four formulations registered as over-the-counter medicines., Methods: Nine hundred sixty-five pharmacy customers purchasing one of four branded ambroxol formulations (extended release capsules, adult syrup, pediatric syrup and soft pastilles) filled a questionnaire including a patient-adapted version of the Bronchitis Severity Scale, several questions on degree of impairment by acute cough, time to onset of symptom relief and duration of treatment. Data on pediatric syrup users were entered by their parents. Based on the exploratory character of the study, no hypothesis-testing statistical analysis was applied., Results: Users of the pediatric syrup and the pastilles reported somewhat less severe baseline symptoms. The patient-adapted Bronchitis Severity Scale proved feasible as a self-administered tool. Among BSS items, ambroxol formulations improved chest pain while coughing to the largest and sputum to smallest degree (- 75% vs. -40%). Reported efficacy was comparable among formulations with minor differences in favor of the pediatric syrup. Time to onset of symptom relief was less than 60 min in more than 90% of patients and occurred prior to known systemic t max . Time to onset was the parameter with the greatest differences between formulations, being reported fastest with pastilles and pediatric syrup and, as expected, slowest with extended release capsules. All ambroxol formulations were well tolerated., Conclusions: We conclude that over-the-counter formulations of ambroxol exhibit comparable user profiles and efficacy. Differences in speed of onset of symptom relief may involve not only those in systemic pharmacokinetics but also local anesthetic effects of immediate release formulations. Differences between pediatric and adult syrup may in part reflect reporting bias.

In this work, we show how to obtain efficient dynamic nuclear polarization (DNP) enhanced 35 Cl solid-state NMR (SSNMR) spectra at 9.4 T and demonstrate how they can be used to characterize the molecular-level structure of hydrochloride salts of active pharmaceutical ingredients (APIs) in both bulk and low wt% API dosage forms. 35 Cl SSNMR central-transition powder patterns of chloride ions are typically tens to hundreds of kHz in breadth, and most cannot be excited uniformly with high-power rectangular pulses or acquired under conditions of magic-angle spinning (MAS). Herein, we demonstrate the combination of DNP and 1 H- 35 Cl broadband adiabatic inversion cross polarization (BRAIN-CP) experiments for the acquisition of high quality wideline spectra of APIs under static sample conditions, and obtain signals up to 50 times greater than in spectra acquired without the use of DNP at 100 K. We report a new protocol, called spinning-on spinning-off (SOSO) acquisition, where MAS is applied during part of the polarization delay to increase the DNP enhancements and then the MAS rotation is stopped so that a wideline 35 Cl NMR powder pattern free from the effects of spinning sidebands can be acquired under static conditions. This method provides an additional two-fold signal enhancement compared to DNP-enhanced SSNMR spectra acquired under purely static conditions. DNP-enhanced 35 Cl experiments are used to characterize APIs in bulk and dosage forms with Cl contents as low as 0.45 wt%. These results are compared to DNP-enhanced 1 H- 13 C CP/MAS spectra of APIs in dosage forms, which are often hindered by interfering signals arising from the binders, fillers and other excipient materials.

Three simple, precise, accurate and validated derivative spectrophotometric methods have been developed for the simultaneous determination of levocetirizine dihydrochloride (LCD) and ambroxol hydrochloride (ABH) in bulk powder and in pharmaceutical formulations. The first method is a first derivative spectrophotometric method ((1)D) using a zero-crossing technique of measurement at 210.4 nm for LCD and at 220.0 nm for ABH. The second method employs a second derivative spectrophotometry ((2)D) where the measurements were carried out at 242.0 and 224.4 nm for LCD and ABH, respectively. In the third method, the first derivative of the ratio spectra was calculated and the first derivative of the ratio amplitudes at 222.8 and 247.2 nm was selected for the determination of LCD and ABH, respectively. Calibration graphs were established in the ranges of 1.0-20.0 μg mL(-1) for LCD and 4.0-20.0 μg mL(-1) for ABH using derivative and ratio first derivative spectrophotometric methods with good correlation coefficients. The developed methods have been successfully applied to the simultaneous determination of both drugs in commercial tablet dosage form., (Copyright © 2015 Elsevier B.V. All rights reserved.)

A gastro-retentive capsule has been prepared which is retained in the stomach for a period of 24h, providing a vehicle for the controlled delivery to the upper intestines. These "gastro cocoons" can resist passage through the sphincter of the stomach, and can retain a high drug payload (30%). They are made from oppositely charged polyelectrolytes and can swell to twice their initial volume. They are strong and also can resist 550 N of compressive force. They are based on filled pharmaceutical capsules which are visible to X-rays. Using ambroxol hydrochloride as a model drug linear, zero-order, release curves were obtained.

This study aimed at using near-infrared (NIR) spectroscopy to monitor compaction pressure for simultaneously determining the tensile strength and content uniformity, as well as moisture and mean particle size of ambroxol hydrochloride tablets. The content uniformity, compression force and tensile strength of the laboratory samples were obtained by pressing a mixture of active principle and excipient components into tablets. To reduce the spectral baseline shift of the laboratory samples, the compaction pressure applied to the mixture was assessed by a variable pressure test. Production samples were added to the test and subjected to principal component analysis. The expanded partial least-squares (PLS) calibration model used to quantify the active content was more accurate than the model constructed from laboratory samples using the production tablets included in the calibration set. The model showed good predictability, with correlation coefficient (R) 0.9977. The validation and reliability of the content model were evaluated to determine trueness and reliability for the measurement of individual production tablets and the laboratory tablets with drug content ranging from 24 to 36 mg. The PLS calibration models for compression force and tensile strength were constructed using the same spectral set assuming both were highly related. These models yielded high R values (0.9955 and 0.9910). The R values of the moisture and mean particle size were 0.9994 and 0.9919, respectively. This study demonstrated that NIR spectroscopy combined with chemometric techniques can be successfully used to quantitatively monitor the tablet manufacturing process in the pharmaceutical industry.

The bitterness of 10 different products with ambroxol as active ingredient, the original and nine generics, were evaluated by human gustatory sensation tests in which the tablets were kept in the mouth, with water, at 20 and 37°C. The products all showed different bitterness intensities. The original and some of the generic products had comparatively low bitterness intensities but some of the generic products had comparatively high bitterness intensities. The bitterness intensities of these 10 was found to be significantly correlated with both the disintegration time, as evaluated using the ODT-101 (a recently developed apparatus), and the drug concentration in dissolved medium, as measured in a conventional dissolution test. The bitterness threshold of ambroxol solution was found to increase when the temperature of the water with which the tablets were taken, was raised from 20 to 37°C. The equation was calculated to predict the bitterness intensity of ambroxol, a function based on temperature and the ambroxol concentration using data from a standard ambroxol solution at 4, 20 and 37°C. The bitterness intensities obtained for the 10 ambroxol formulations with water at 20 and 37°C, coincided with the bitterness values predicted by the equation.

This paper reported that a new type of floating osmotic pump of ambroxol hydrochloride was designed. Third method apparatus (Chinese Pharmacopeia 2010, appendix XD) was employed to simultaneously evaluate the release and floating behavior in vitro. The system was optimized using central composite design-response surface methodology. Similar factor (f2) between the release profile of self-made formulation and the target release profile was chosen as dependent factor. The amount of glucose (A, mg), pore former (B, %) and weight of coating (C, %) were employed as independent factors. Optimized formulation was: A (100.99 mg), B (1.70%), C (4.21%). The value of f2 (89.14) was higher than that of market capsules (69.02) and self-made tablets (72.15). It was showed that self-made capsules possessed character of zero-order release (r = 0.994 4) and drug release completely (>90%). It was showed in result of in vivo study that tmax and Cmax of self-made capsules were significantly lower than that of market capsules and self-made tablets. The correlation coefficient between the fraction of absorption in vivo and the release rate in vitro was 0.985 1, and relative bioequivalence of self-made capsules was 110.77%. Accordingly, self-made capsules displayed obviously characteristics of controlled release both in vivo and in vitro.

This study was carried out to develop and optimize oral sustained-release formulations for Ambroxol hydrochloride matrix pellets using a combination of wax and water-insoluble polymer, glyceryl behenate (Compritol 888 ATO) and Ethylcellulose (EC(7 FP)). It involved three factors: the content of Compritol 888 ATO (X(1)), EC(7 FP) (X(2)), and the matrix formation methods (X(3)), as independent variables. The drug release percentages at 1, 2 and 4 h were the target responses and were restricted to 15-45% (Y(1)), 45-80% (Y(2)) and 80-100% (Y(3)), respectively. The final blend formulation prepared by extrusion spheronization, was achieved with 27.00% (w/w) Ambroxol hydrochloride, 48.70% (w/w) Compritol 888 ATO, and 24.30% (w/w) EC(7 Fp) with 40 degrees C for 12 h. Comparing the single matrix materials consisting of just the wax or water-insoluble in the complex matrix system containing wax and water-insoluble polymer, the release of the drug can be far more retarded, when the formulations have undergone the process of heat treatment. Furthermore, the combination of the two polymers, with flexible matrix formation methods, will offer a very promising way of producing matrix pellets instead of coated controlled-release pellets to meet various demands of drug release.

Gaucher disease (GD), the most prevalent lysosomal storage disease, is caused by a deficiency of glucocerebrosidase (GCase). The identification of small molecules acting as agents for enzyme enhancement therapy is an attractive approach for treating different forms of GD. A thermal denaturation assay utilizing wild type GCase was developed to screen a library of 1,040 Food and Drug Administration-approved drugs. Ambroxol (ABX), a drug used to treat airway mucus hypersecretion and hyaline membrane disease in newborns, was identified and found to be a pH-dependent, mixed-type inhibitor of GCase. Its inhibitory activity was maximal at neutral pH, found in the endoplasmic reticulum, and undetectable at the acidic pH of lysosomes. The pH dependence of ABX to bind and stabilize the enzyme was confirmed by monitoring the rate of hydrogen/deuterium exchange at increasing guanidine hydrochloride concentrations. ABX treatment significantly increased N370S and F213I mutant GCase activity and protein levels in GD fibroblasts. These increases were primarily confined to the lysosome-enriched fraction of treated cells, a finding confirmed by confocal immunofluorescence microscopy. Additionally, enhancement of GCase activity and a reduction in glucosylceramide storage was verified in ABX-treated GD lymphoblasts (N370S/N370S). Hydrogen/deuterium exchange mass spectrometry revealed that upon binding of ABX, amino acid segments 243-249, 310-312, and 386-400 near the active site of GCase are stabilized. Consistent with its mixed-type inhibition of GCase, modeling studies indicated that ABX interacts with both active and non-active site residues. Thus, ABX has the biochemical characteristics of a safe and effective enzyme enhancement therapy agent for the treatment of patients with the most common GD genotypes.

The aim of the present study is to perform stability study of ambroxol hydrochloride sustained release pellets stored in different storage conditions. The drug loaded beads were prepared by extrusion-spheronization technology then coated with ammonio methacrylate copolymer type A (Eudragit RL 30 D) and ammonio methacrylate copolymer type B (Eudragit RS 30 D) at a ratio of 2:3 (8% polymer by weight on dry basis) in fluid bed coater (Wurster column). Stability study of pellets was performed as capsule dosage form in aluminium-PVDC packaging mode at room temperature, 40 degrees C, 40 degrees C/75%RH & 30 degrees C/70%RH for three months. After one month the shape & size of the pellets was changed in all conditions. The color of the pellets remains unchanged up to the 2nd month in all conditions except at 40 degrees C/75%RH and in this case some pellets become brown. But after 3rd month, pellets become brownish in all conditions except at room temperature. At RT the color of pellets remains unchanged during the stability study. The mean drug content decreased gradually in all conditions. In acid media the initial drug release was 23% but after 1st month it was decreased to 13-15% in all conditions. In the buffer media (pH 6.8) the drug release was increased a little bit in all conditions except at 30 degrees C/70%RH with the passes of storage time. Stability studies at 30 degrees C/70%RH revealed consistent drug release (f(2)>50) throughout the stability period. The physical properties of pellets as well as the in vitro release profile of the drug was found to be a function of the different storage conditions as well as the physico-chemical nature of the polymers.

A simple, precise and accurate reversed-phase liquid chromatographic method has been developed for the simultaneous estimation of ambroxol hydrochloride and azithromycin in tablet formulations. The chromatographic separation was achieved on a Xterra RP18 (250 mm x 4.6 mm, 5 microm) analytical column. A Mixture of acetonitrile-dipotassium phosphate (30 mM) (50:50, v/v) (pH 9.0) was used as the mobile phase, at a flow rate of 1.7 ml/min and detector wavelength at 215 nm. The retention time of ambroxol and azithromycin was found to be 5.0 and 11.5 min, respectively. The validation of the proposed method was carried out for specificity, linearity, accuracy, precision, limit of detection, limit of quantitation and robustness. The linear dynamic ranges were from 30-180 to 250-1500 microg/ml for ambroxol hydrochloride and azithromycin, respectively. The percentage recovery obtained for ambroxol hydrochloride and azithromycin were 99.40 and 99.90%, respectively. Limit of detection and quantification for azithromycin were 0.8 and 2.3 microg/ml, for ambroxol hydrochloride 0.004 and 0.01 microg/ml, respectively. The developed method can be used for routine quality control analysis of titled drugs in combination in tablet formulation.

A rapid, simple and sensitive LC-MS/MS method was developed for simultaneous determination of amoxicillin and ambroxol in human plasma using clenbuterol as internal standard (IS). The plasma samples were subjected to a simple protein precipitation with methanol. Separation was achieved on a Lichrospher C(18) column (150 mm x 4.6mm ID, dp 5 microm) using methanol (containing 0.2% of formic acid) and water (containing 0.2% of formic acid) as a mobile phase by gradient elution at a flow rate of 1.0 mL/min. Detection was performed using electrospray ionization in positive ion multiple reaction monitoring (MRM) mode by monitoring the ion transitions from m/z 365.9-->348.9 (amoxicillin), m/z 378.9-->263.6 (ambroxol) and m/z 277.0-->203.0 (IS). Calibration curves were linear in the concentration range of 5-20,000 ng/mL for amoxicillin, and 1-200 ng/mL for ambroxol, with the intra- and inter-run precisions of <9% and the accuracies of 100+/-7%. The method has been validated and applied to pharmacokinetic studies of compound amoxicillin and ambroxol hydrochloride tablets in healthy Chinese volunteers.

The objective of this study is to evaluate the influence of formulation and preparation process on ambroxol hydrochloride (AH) dry powder inhalation (DPI) characteristics and aerosolization properties. Spray-dried samples of AH, AH/leucine, and AH/leucine/mannitol were prepared from their corresponding water solutions under the same conditions to study the influence of the composition, and the AH/leucine/mannitol (2.5/0.5/1 by weight) formulation was used for investigation of the effect of the preparation process. Following spray-drying, the resulting powders were characterized using scanning electron microscopy, laser diffraction, tapped density, and angle of repose measurements, and the aerosolization performance was determined using a twin-stage liquid impinger. AH/leucine/mannitol (2.5/0.5/1 by weight) obtained by cospray-drying improved the AH aerosolization properties. The AH/leucine/mannitol (2.5/0.5/1 by weight) preparation exhibited the following properties: 62.34% yield, 0.34 g/cm(3) tap density, 2.71 microm d(ae), 33.45 degrees angle of repose, and 30.93% respirable fraction. The influence of the preparation process on DPI characteristics and aerosolization properties was relatively small, but the influence of the composition was relatively large. Optimization of DPI can be achieved by selecting the most appropriate formulation and preparation process.

The RP-HPLC (reverse phase high performance liquid chromatography) method was developed and validated for simultaneous determination of Multi drug components i.e., Theophylline, Etofylline, Guaiphenesine and Ambroxol Hydrochloride in a liquid dosage form. Chromatographic separation of the four drugs was performed on a Hypersil Phenyl BDS (25cmX4.6mm, 5mm). The mobile phase constituted of triethylamine pH 3.0 buffer: methanol (85:15) v/v was delivered at the flow rate 1.5 mL/min. Detection was performed at 235 nm. The peak purity of Theophylline, Etofylline, Guaiphenesine and Ambroxol Hydrochloride were 0.99970, 0.99979, 0.99986 and 0.99949 respectively. Calibration curves were linear with correlation coefficient between 0.99995 to 0.99997 over a concentration range of 5 to 37 microg/mL for Theophylline, 19 to 140 microg/mL for Etofylline, 20 to 149 microg/mL for Guaiphenesine and 6 to 45 microg/mL for Ambroxol hydrochloride. The relative standard deviation (RSD) was found < 2.0%. The percentage recovery was found between the range of 98.6% and 100.5% at three different levels. Robustness and ruggedness were performed and result found within the RSD of 2%. All the parameters of validation were found in the acceptance range of ICH guideline.

For almost three decades ambroxol has been used in the therapy of airway diseases. In 2002, ambroxol lozenges were marketed for the treatment of sore throat making use of its local anesthetic effect. Detailed investigations of ambroxol with modern pharmacological methods yielded additional interesting results: ambroxol has been found to have profound effects on neuronal voltage-gated Na(+), as well as Ca(2+) channels, and to effectively reduce chronic inflammatory and neuropathic pain in rodents. The question was raised whether ambroxol affects the central nervous system (CNS) directly, or whether its effects can be explained solely by a peripheral action. This issue was addressed by re-examining pharmacokinetics, as well as toxicology of ambroxol. It has been concluded that even at the highest clinically used doses ambroxol does not have significant direct effects on the CNS. At clinically relevant plasma concentrations ambroxol either does not penetrate blood-brain barrier, or its brain levels are too low to cause relevant effects. The analgesic effects of ambroxol by either systemic administration to animals, or by topical application in humans can be explained by ambroxol-induced blockade of ion channels in peripheral neurons.

Ambroxol is an expectoration improver and mucolytic agent that has been used to treat acute and chronic disorders. However, ambroxol needs to be administered percutaneously in order to avoid systemic adverse effects, such as headache, drowsiness, dizziness, and insomnia, which can occur after oral administration. The aim of this study was to develop a gel preparation containing a permeation enhancer to enhance the delivery of ambroxol. The ambroxol gels were prepared using hydroxypropyl methylcellulose (HPMC) and poloxamer 407. The release characteristics of the drug from the gels were examined according to the receptor medium, drug concentration, and temperature. The rate of drug permeation into the skin was enhanced by incorporating various enhancers such as the ethylene glycols, the propylene glycols, the glycerides, the non-ionic surfactants, and the fatty acids into the gels. The permeation study through mouse skin was examined at 37 C. The rate of drug release increased with increasing drug concentration and temperature. Among the enhancers used, propylene glycol mono caprylate showed the best enhancing effects. The estimated activation energy of release (Ea), which was calculated from the slope of a log P versus 1000/T plot, was 14.80, 14.22, 13.91, and 12.46 kcal/mol for ambroxol loading doses of 2, 3, 4, and 5%, respectively. The results of this study show that the gel preparation of ambroxol containing a permeation enhancer could be developed for the enhanced transdermal delivery of ambroxol.

The active pharmaceutical ingredient (ambroxol) in an intact capsule formulation has been non-destructively quantified using Raman spectroscopy. To improve the problem of insufficient representative sampling inherent in Raman measurements, we have employed a wide area illumination (WAI) scheme that enables much improved sample coverage through a circular excitation laser spot with a 6 mm diameter. One of the anticipated sources of variation for this measurement was variation in the capsule shells. However, the WAI scheme significantly decreased the spectral variation among empty capsules compared to a measurement with a traditional small-spot excitation. Therefore, measurement variations emanating from the capsule shell did not significantly influence the accuracy of the determination of ambroxol concentrations. The resulting standard error of prediction (SEP) using the WAI scheme was comparable to that from previous Raman measurements which used a conventional small-spot excitation and employed a sampling scheme that involved rotation of an ambroxol pellet. It is further noteworthy that the SEP was also similar to that obtained from the use of transmission NIR spectroscopy, which was achieved by collection of spectra of the powdered capsule contents removed from the shell. The proposed Raman measurement using the WAI scheme in this case was sufficient to achieve the quantitative measurement of the active pharmaceutical ingredient (API) content of capsules non-destructively.

Ambroxol theophylline-7-acetate (ACE) is the salt obtained by reaction of equimolar amounts of ambroxol (AMB), a drug showing mucolytic and expectorant properties, and theophylline-7-acetic acid (TAA), a xanthine derivative with specific bronchodilator activity. ACE is used for the treatment of bronchial and pulmonary diseases (bronchitis, asthma, emphysema, chronic obstructive disease). Recrystallization experiments of ACE resulted in the isolation of two polymorphs (monotropically related) and four solvated forms. X-ray diffractometry, DSC, TGA, and HSM techniques were used to investigate the forms that are obtained by thermal desolvation of the solvates. The phase diagram of the TAA-AMB binary system was constructed by performing thermal analyses on mixtures of TAA-AMB and of each component plus the interaction compound (TAA-ACE and ACE-AMB). The Schroeder-Van Laar equation proved to be a very useful tool for checking the consistency between the experimental data and the theoretical model related to the general system, showing complete miscibility in the liquid phase and complete immiscibility in the solid phase., ((c) 2007 Wiley-Liss, Inc. and the American Pharmacists Association.)

The aim of the study was to compare the gelation and drug release characteristics of formulations of pectin with high (31%) and low (9%) degrees of methoxylation over a wide pH range (pH 1.2-5.0). Dilute solutions of pectin (1.5%, w/v) containing complexed calcium ions formed gels in vitro at low pH (pH<2.5) as a consequence of cross-linking of the galacturonic chains by calcium ions released from the complex, but the efficiency of gelation was significantly reduced with increase of pH because of incomplete release of complexed Ca(++). Gelation of formulations of pectin with a degree of esterification of 9% (DE9) was observed over the pH range 2.5-5.0 in the presence of 1.6mM Ca(++), but was incomplete in formulations of pectin with a degree of esterification of 31% (DE31). A sustained release of ambroxol was observed following oral administration of pectin DE9 formulations to gastric-acidity controlled rabbits at pH 5.5-5.7 and visual observation of the stomach contents of these rabbits confirmed in situ gelation of these formulations. There was no evidence of in situ gelation of pectin DE31 formulations under these conditions and a rapid initial drug release was observed. Differences in gelling characteristics in this pH range were attributed to the greater susceptibility of low methoxylated pectin to cross-linking by di- and tri-valent ions present in the gastric juice. It is concluded that formulations of pectin with a low degree of esterification have potential application as in situ gelling vehicles for the sustained delivery of drugs following oral administration under conditions of high gastric pH.

The aim of this study was to examine the influence of variation of gastric pH over the range 1-3 on the gelation of liquid formulations of pectin and on the in vitro and in vivo release of paracetamol and ambroxol from the resultant gels. The formulations were dilute solutions of pectin containing complexed calcium ions that form gels when these ions are released in the acidic environment of the stomach. Gels suitable as vehicles for sustained delivery of these drugs were formed in vitro at pH<3 from pectin solutions of concentrations 1.0-2.0% (w/v). Very weak gels were formed at pH 3.0 resulting in poor sustained release characteristics compared with those at pH 1.2; no significant in vitro gelation was observed at pH 3.5. The bioavailabilities of paracetamol and ambroxol from gels formed in the stomach following oral administration of the liquid formulations were investigated using gastric-acidity controlled rabbits. Visual observations showed in situ gelation of 1.5% (w/v) pectin formulations under conditions of both high (pH 1.0-1.6) and low gastric acidity (pH 3.3-3.6). The bioavailabilities of these drugs were not significantly different when released from gels formed at the two pH limits suggesting that normal variations of gastric acidity in the fasting state will have no effect on the bioavailability of these drugs when delivered using this vehicle.

A liquid chromatography-mass spectrometry (LC-MS) method for the determination of roxithromycin in rat lung tissue is described. Liquid-liquid extraction was adopted for sample preparation with recoveries from 72.5 to 76.9% at levels of 0.1, 5.0 and 20.0 microg/ml. Chromatographic separation was performed on a C18 column using a mixture of methanol, water and formic acid (80:20:1, v/v/v) as mobile phase delivered at a flow rate of 0.5 ml/min. Positive selected ion monitoring (SIM) mode was used for the quantification of roxithromycin at m/z 837.7 and clarithromycin (internal standard) at m/z 748.7. The linearity was obtained over the concentration range of 0.05-20.0 microg/ml and the lower limit of quantification was 0.05 microg/ml. For each QC level of roxithromycin, the intra- and inter-day precisions relative standard deviation (R.S.D.) were less than 4.1 and 7.5%, respectively, and accuracy (RE) was +/-10.0%. The proposed LC-MS method has been successfully used for the determination of roxithromycin in rat lung tissue after oral administration of roxithromycin formulations to 44 SD rats. The present study demonstrates that the concentration of roxithromycin in rat lung tissues can be significantly increased by ambroxol when they are formulated in combination.

Gels formed in situ following oral administration of dilute aqueous solutions of pectin (1.0 and 1.5%, w/v) to rats were evaluated as vehicles for the sustained release of the expectorant drug ambroxol hydrochloride. The solutions contained calcium ions in complexed form, which on release in the acidic environment of the stomach caused gelation of the pectin. In vitro studies demonstrated diffusion-controlled release of ambroxol from the gels over a period of 6 h. A bioavailability of ambroxol of approximately 64% of that of a commercially available formulation could be achieved from gels containing an identical dose of ambroxol formed in situ in the stomachs of rats, with appreciably lower peak plasma levels and a sustained release of drug over a period of at least 6 h. The influence of added sorbitol (17%, w/v) on the rheological and drug release properties of the formulations has been examined.

Potentiometric detection of clenbuterol, ambroxol and bromhexine in marketed pharmaceuticals was described in six isocratic HPLC systems. The podant- and macrocyclic-type neutral ionophores, N,N,N',N'-tetracyclohexyl-oxybis(o-phenyleneoxy)diacetamide (TOPA) and hexakis(2,3,6-tri-O-octyl)-alpha-cyclodextrin (OCD), were applied in poly(vinyl)chloride (PVC)-based liquid membrane electrodes. Both types of neutral ionophores improve the sensitivity for all mentioned drugs when compared with a tetrakis(p-chlorophenyl)borate (BOR)-based electrode as well as with single wavelength UV detection. Detection limits (S/N=3) of 2.6 x 10(-10) mol l(-1) (injected concentration) for the highly hydrophobic bromhexine were achieved with the TOPA-based electrode and a cyano reversed-phase (RP)-HPLC with Uptisphere UP5CN-25QS silica column (250 x 4.6 mm i.d.) eluted with acetonitrile (AcN)-ethanol-perchloric acid (1.66 mM) (60:2:38, v/v/v) (pH* 2.45). Comparable result was obtained with OCD-based electrodes and an XTerra RP18 hybrid silica-polymer column eluted with AcN-phosphoric acid (20 mM) (25:75, v/v) (pH* 2.60). In the mobile phases containing 60-75% v/v AcN or methanol, stable and reproducible response of both types of neutral ionophore-based electrodes was observed for at least 3 days. The results of the validated procedure for reliable simultaneous determination of the drugs in fortified representative samples of pharmaceuticals were also presented.

New ambroxol (Amb) ion selective plastic membrane electrodes of both conventional and coated graphite types based on the ion-pair of ambroxolium tetraphenylborate (Amb-TPB) ion-pair are prepared. The conventional type electrode was fully characterized in terms of membrane composition, life span, pH, ionic strength and temperature. It was applied to potentiometric determination of ambroxol in pure solutions and pharmaceutical preparations under batch and flow injection conditions. The potentiometric determination was used in the determination of ambroxol in muco syrup in four batches of different expiry dates, also the amounts of ambroxol released after 1, 8 and 16 h from the muco sustained release type (S.R.) capsules were also assayed. The selectivity of the electrode toward a large number of excipient like inorganic cations, sugars and amino acids was tested. The solubility product of the ion-pair and the formation constant of the precipitation reaction leading to the ion-pair formation were determined conductimetrically.

Ambroxol and bromhexine are shown to be scavengers of both superoxide and hydroxyl radicals as determined by pulse radiolysis experiments. The dismutation of superoxide was accelerated 3-fold by bromhexine and 2.5-fold by ambroxol over the rate of spontaneous dismutation. The reaction constants of hydroxyl radicals with bromhexine and ambroxol were determined by competition kinetics to be 1.58 +/- 0.15 x 10(10) M-1S-1 and 1.04 +/- 0.1 x 10(10) M-1S-1, respectively. N-acetyl-L-cysteine also reacted with hydroxyl radicals (1.28 +/- 0.14 x 10(10) M-1S-1) but not with superoxide radical. These effects may be clinically relevant in the treatment of oxidant-associated lung damage induced by inflammatory agents and/or environmental pollutants.

Experimental studies have suggested that ambroxol, a drug clinically used to enhance pulmonary surfactant production, may also exert some anti-inflammatory effects, though specific mechanisms are not yet fully understood. Thus, potential scavenging properties of ambroxol towards the most toxic neutrophil-arising prooxidants hypochlorous acid and monochloramine were investigated. We have found that the drug at 25, 50 and 100 mumol/l exerted a significant, concentration-related antagonizing effect on both chlorine species, with a maximal specific activity detected against hypochlorous acid. These new pharmacological properties of ambroxol may play a role in vivo in disease entities characterized by white blood cell activation and uncontrolled oxidant generation, such as inflammatory/ischemic conditions.