Relative bioavailability and pharmacokinetic comparison of a fixed-dose combination tablet of mosapride, pancreatin, and simethicone relative to single-component mosapride tablets in healthy Mexican subjects.

Abbott Laboratories de México S.A. de C.V. developed a new fixed-dose combination of mosapride 5 mg, pancreatin 170 mg, and simethicone 125 mg as an alternative to the mosapride monotherapy to improve overall satisfaction and adequate relief of gastrointestinal disorders symptoms and to reduce multiple pill burden. As a part of the fixed-dose combination registration process in Mexico, a pharmacokinetic and relative bioavailability study was carried out to demonstrate nonexistence of pharmacokinetic interaction when mosapride is administered alone or in combination with pancreatin and simethicone using DOSIER® (mosapride) 5-mg tablets as a reference product. Tolerability of the fixed-dose combination tablet was assessed. In this open-label, randomized, oral single-dose, two-way crossover study, 65 healthy male and female subjects received either the fixed-dose combination tablet or the reference product during each study period. The two study periods were separated by a 7-day washout period. Mosapride concentrations in plasma samples were determined using a validated ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) method. Blood samples were collected for up to 16 h post dose. The primary evaluation criteria were Cmax and AUC0-t for mosapride. The 90% confidence intervals for the ratio of geometric means for Cmax (96.12% to 110.90%) and AUC0-t (99.07% to 108.06%) were within the defined acceptance limits of 75% to 133% and 80% to 125% for Cmax and AUC0-t , respectively, indicating bioequivalence between the two products. Both products were safe and well tolerated. Therefore, mosapride in combination with pancreatin and simethicone tablet is bioequivalent to mosapride alone, and no new safety signals emerged.

Bioequivalence and Tolerability of Ambrisentan: A Pharmacokinetic Study in Mexican Healthy Male Subjects.

BACKGROUND: Pulmonary arterial hypertension (PAH) is a disease characterized by a progressive rise in pulmonary vascular resistance. Ambrisentan is an oral, propanoic acid based-endothelin receptor antagonist (ERA), selective for the endothelin type-A receptor, which is approved for the treatment of PAH. The Colombia National Food and Drug Surveillance Institute regulatory criteria require demonstrating that the proposed generic product is bioequivalent to its reference-listed drug to obtain marketing approval. OBJECTIVES: The purpose of this study was to test the bioequivalence, pharmacokinetics, and tolerability of ambrisentan 10 mg tablets. METHODS: In this open-label, randomized, oral single-dose, two-way crossover bioequivalence study, 26 Mexican adult healthy male subjects received either the generic product of ambrisentan 10 mg or the reference product Volibris® (ambrisentan) 10 mg tablets during each study period under fasting conditions. There was a 7-day washout period between each dosing. Ambrisentan concentrations in plasma samples were quantified using a validated ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) method. Blood samples were collected up to 72 h post-dose in each study period. The primary end points were maximum plasma concentration (Cmax) and area under the plasma concentration-time (AUC0-t) curve between 0 and 72 h for ambrisentan. RESULTS: The ratios (90% CI) of geometric mean for ambrisentan were 104.3% (97.12-111.98%) and 100.2% (95.56-104.72%). These pharmacokinetic parameter values lie within the INVIMA-specified bioequivalence limits of 80%-125%. Nervous system disorders were the most common adverse events (AEs). All AEs were mild to moderate in nature and were resolved after follow-up or pharmacologic treatment. Both products were safe and well tolerated. CONCLUSIONS: The test product ambrisentan 10 mg tablets is bioequivalent to the reference product Volibris® (ambrisentan) 10 mg tablets. Both treatments were well tolerated in the Mexican male population of this study. TRIAL REGISTRATION: COFEPRIS National Clinical Trials Registry number 183300410B0367/2018.

Evaluation of Different Light Conditions in the Working Environment for Handling Photosensitive and Thermolabile Compounds.

Lighting in the working environment plays a significant role on the degree of degradation of photosensitive, thermolabile compounds and on working efficiency. Light emitting diodes (LEDs) are semiconductor light emitting devices that are promising artificial light sources with easy modulation of light wave signals and are also known for low heat generation. Therefore, the effect of polychromatic LED light was tested in the working environment using the drug compounds montelukast, nifedipine, and clavulanic acid, which are known to be photosensitive or thermolabile. As a control, other lighting sources like a sodium lamp, a classic (incandescent, tungsten) lamp, and indirect sunlight were also used in this study. All the experiments were carried out with methanolic solutions at room temperature. An Acquity UPLC/MS/MS system was used for quantification of the main analytes and degradation products. Under the tested conditions, LED lighting proved to be more suitable for handling photosensitive and thermolabile compounds.

Impurity profiling of capreomycin using dual liquid chromatography coupled to mass spectrometry.

The characterization of unknown (UNK) impurities in capreomycin (CMN) using liquid chromatography coupled to mass spectrometry (LC/MS) has been described. The ion-pair liquid chromatography method coupled to ultraviolet detection (LC-UV) described by Mallampati et al. was used for the separation of CMN from its related substances. As the method uses non-volatile reagents it could not be directly coupled to mass spectrometry (MS) for impurity characterization. So, these UNK impurities were collected and desalted before sending to MS for structural characterization. As no information about the fragmentation of the main components of CMN, except for CMN IB, was available in the literature, they were studied first. Next, the structures of the impurities were deduced by comparing their fragmentation to that of the main components of CMN. Fourteen UNK impurities that were never described before, were (partly) characterized.

Simultaneous determination of lidocaine hydrochloride, hydrocortisone and nystatin in a pharmaceutical preparation by RP-LC.

A liquid chromatographic (LC) method was developed to analyze a formulation (mouthwash) containing lidocaine hydrochloride, hydrocortisone and nystatin. A single LC method with UV detection was developed. A Waters Symmetry C18 HPLC column (150 mm × 4.6 mm, 5 µm) was used as stationary phase and the assay was performed with gradient elution using mobile phases containing methanol - 0.1M NaH(2)PO(4) with a pH that was previously adjusted to 4.5 with dilute phosphoric acid. The sample pretreatment was performed by treating the formulation with methanol followed by filtration. After method development, the influence of the different chromatographic parameters on the separation, the interference of other active compounds and excipients, linearity, accuracy, repeatability and intermediate precision were investigated. The method was shown to be selective, linear, accurate, precise and repeatable. Finally, the content of the compounds in the formulation was determined.

Impurity profiling of acetylspiramycin by liquid chromatography-ion trap mass spectrometry.

Investigation of acetylspiramycin (ASPM) and its related substances was carried out using a reversed-phase liquid chromatography/tandem mass spectrometry method. The identification of impurities in the ASPM complex was performed with a quadrupole ion trap mass spectrometer, with an electrospray ionization (ESI) source in the positive ion mode which provides MS(n) capability. A total of 83 compounds were characterized in commercial samples, among which 31 impurities that had never been reported and 31 partially characterized impurities were deduced using the collision-induced dissociation (CID) spectra of major ASPM components as templates. Most of the major impurities arise from the starting materials and the synthesis process. This work provides very useful information for quality control of ASPM and evaluation of its synthesis process.

Characterization of emtricitabine related substances by liquid chromatography coupled to an ion trap mass spectrometer.

Emtricitabine (FTC) is an antiretroviral compound that inhibits the HIV-1 reverse transcriptase. For the quantification of FTC related substances, a liquid chromatography (LC) method coupled with ultraviolet (UV) detection was developed earlier in our laboratory. Several unknown compounds were detected during the analysis of a commercial sample. However, most of these impurities were not characterized. In this study, impurity profiling in a selected FTC sample was done using LC-mass spectrometry (MS). Due to the presence of a non-volatile buffer, a desalting procedure was carried out before sending the impurity into the MS. Totally, nine peaks were studied and most of them could be characterized.

LC-MS of streptomycin following desalting of a nonvolatile mobile phase and pH gradient.

Streptomycin (SM) is composed of streptidine, streptose and N-methyl glucosamine sugar moieties. For the determination of SM and its related substances, an ion-pair LC-UV detection method using a Supelcosil LC-ABZ column was developed previously. While analyzing commercial samples, several unknown compounds were detected. Most of these compounds are not yet characterized. In this study, the above LC method was coupled to MS for impurity profiling in a selected commercial sample. However, it could not be directly coupled to MS due to the presence of the nonvolatile salt, buffer and ion-pair reagent in the mobile phase. So, for structural characterization, each peak eluted from the nonvolatile eluent system was collected and transferred to MS after the desalting process. In total, 16 compounds were studied, 15 compounds including 12 unknowns could be identified.

Characterization of dihydrostreptomycin-related substances by liquid chromatography coupled to ion trap mass spectrometry.

Dihydrostreptomycin sulphate (DHS) is a water-soluble, broad-spectrum aminoglycoside antibiotic. For quantitative analysis, the European Pharmacopoeia (Ph. Eur.) prescribes an ion-pairing liquid chromatography/ultraviolet (LC/UV) method using a C18 stationary phase. Several unknown compounds were detected in commercial samples. Hence, for characterization of these unknown peaks in a commercial DHS sample, the Ph. Eur. method was coupled to mass spectrometry (MS). However, since the Ph. Eur. method uses a non-volatile mobile phase, each peak eluted was collected and desalted before introduction into the mass spectrometer. The desalting procedure was applied to remove the non volatile salt, buffer and ion-pairing reagent in the collected fraction. In total, 20 impurities were studied and 14 of them were newly characterized. Five impurities which are already reported in the literature were also traced in this LC/UV method.

Powder for reconstitution of the anti-HIV-1 drug TMC278 - Formulation development, stability and animal studies.

Powders for reconstitution of the next-generation non-nucleoside reverse transcriptase inhibitor (NNRTI) TMC278 with low water solubility were developed by using a spray-dry technology. Their flexible dosing ability makes them suitable for patients looking for a different approach for antiretroviral (ARV) therapy. The selection of formulation excipients was based on their potential to create and maintain supersaturation solubility of TMC278 in 0.01 M HCl. Suitable water-soluble carriers for TMC278 were selected by a supersaturation screening to formulate powders for reconstitution by spray-drying. The selected powders for reconstitution were compared to clinical tablets of TMC278.HCl, in vitro using dissolution and stability testing, and in vivo through administration to beagle dogs, fed immediately after dosing. The spray-dried powders for reconstitution made up of TMC278/PVP-VA 64 1:9 (w/w) and TMC278/PVP-VA 64/Cremophor EL 1:8.5:0.5 (w/w/w) showed ease of suspendability, nearly complete dissolution of the drug and acceptable stability after one month storage at 25 and 40 degrees C. In dogs, TMC278 was more slowly absorbed from tablets than from the suspended powders for reconstitution. Compared to the tablet, the relative bioavailability obtained with the powders ranged between 69% and 89% for TMC278/PVP-VA 64 1:9 (w/w) and between 85% and 157% for TMC278/PVP-VA 64/Cremophor EL 1:8.5:0.5 (w/w/w). The absence of differences in vivo and in vitro between the powders made an eventual choice very difficult, yet their advantageous in vivo behaviour and flexible dosing possibility may provide a starting point for paediatric formulations.

Development of a liquid chromatographic method for the determination of related substances and assay of d-cycloserine.

d-cycloserine or d-4-amino-3-isoxazolidinone is an antibiotic produced by Streptomyces garyphalus and Streptomyces orchidaceus. d-Cycloserine is used in the second line treatment of tuberculosis and is often used in developing countries. Therefore, expensive high-tech techniques are not recommended for analysis. Here, a liquid chromatography method with ultraviolet detection (LC-UV) is described using a base deactivated column (Hypersil BDS column; 25 cm x 4.6 mm I.D.) kept at 45 degrees C. The gradient method uses mobile phases containing acetonitrile (ACN), 20mM sodium octane sulphonate (SOS), 0.2M potassium dihydrogen phosphate buffer pH 2.8, water: A: (4:70:10:16v/v/v/v) and B: (17:70:10:3v/v/v/v). The method proved to be robust, linear, repeatable, sensitive, selective and easy to perform. For the related substances test 50 microl of a 0.5 mg/ml d-cycloserine solution is injected. For assay, a concentration of 0.1 mg/ml is proposed to avoid overloading of the detector.

Combination of a liquid chromatography-ultraviolet method with a non-volatile eluent, peak trapping and a liquid chromatography-mass spectrometry method with a volatile eluent to characterise erythromycin related substances.

The selectivity and sensitivity obtained with volatile liquid chromatographic (LC) methods are often inferior compared to non-volatile ones. However, the buffers often used in the non-volatile system are incompatible to mass spectrometry (MS). So, the characterisation of unknown peaks in a non-volatile system, based on data obtained from a volatile LC-MS method, is problematic. In this study, the unknown peaks in a non-volatile liquid chromatography coupled with ultraviolet detection (LC-UV) system were directly characterised by a volatile LC-MS system using a peak trapping technique. Each peak eluted from the non-volatile system was trapped by a switching valve and sent to a LC-MS system using a volatile mobile phase. Mass spectral data were acquired on an LCQ ion trap mass spectrometer equipped with electrospray ionisation (ESI) operated in the positive ion mode. Using this technique, the fragmentation behaviour of erythromycin and its related substances was studied and the components occurring in commercial samples were investigated. In total 25 compounds mentioned in the literature were traced. Fourteen more unknown impurities were also studied.

Characterization of impurities in spiramycin by liquid chromatography/ion trap mass spectrometry.

A reversed-phase liquid chromatography/tandem mass spectrometry method is described for the investigation of spiramycin and related substances. The method uses an XTerra C18 column (250 x 4.6 mm i.d.), 5 microm, and a mobile phase consisting of acetonitrile, methanol, water and ammonium acetate solution, pH 6.5. Mass spectral data were acquired on an LCQ ion trap mass spectrometer equipped with atmospheric pressure chemical ionization (APCI) operated in the positive ion mode. Using this method, the fragmentation behavior of spiramycin and its related substances was studied and the unknown impurities occurring in commercial samples were investigated. In total 17 compounds were identified, among which three reported as specified impurities in the European Pharmacopoeia. The other impurities showed mainly a modification in the forosamine sugar or in the substituent at C-3 and C-6 positions. In one impurity, the mycarose sugar is absent.