RESUMEN
During preformulation studies of cosmetic/pharmaceutical products, thermal analysis techniques are very useful to detect physical or chemical incompatibilities between the active and the excipients of interest that might interfere with safety and/or efficacy of the final product. Differential scanning calorimetry (DSC) was used as a screening technique for assessing the compatibility of avobenzone with some currently used cosmetic excipients. In the first phase of the study, DSC was used as a tool to detect any interaction. Based on the DSC results alone, cetearyl alcohol, isopropyl myristate, propylparaben, diethylhexyl syringylidene malonate, caprylic capric triglyceride, butylated hydroxytoluene (BHT), glycerin, cetearyl alcohol/ceteareth 20, cetearyl alcohol/sodium lauryl sulfate/sodium cetearyl sulfate, and paraffinum liquidum exhibit interaction with avobenzone. Stressed binary mixtures (stored at 50°C for 15 days) of avobenzone and excipients were evaluated by high-performance liquid chromatography. Binary mixtures were further investigated by infrared (IR) spectroscopy. Based on DSC, isothermal stress testing, and fourier transform infrared results; avobenzone is incompatible with caprylic capric triglyceride, propylparaben, and BHT.
Asunto(s)
Hidroxitolueno Butilado/química , Caprilatos/química , Excipientes/química , Parabenos/química , Propiofenonas/química , Protectores Solares/química , Rastreo Diferencial de Calorimetría , Cromatografía Líquida de Alta Presión , Incompatibilidad de Medicamentos , Estabilidad de Medicamentos , Humanos , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Triglicéridos/químicaRESUMEN
An isocratic HPLC method was developed and validated for the quantitation of methocarbamol in the presence of its degradation products. Quantitation was achieved using a reversed-phase C18 column at ambient temperature with mobile phase consisting of methanol-water-tetrahydrofuran (25 + 65 + 10, v/v). The flow rate was 0.9 mL/min. The detection was by UV light at 274 nm. The proposed method was validated for selectivity, precision, linearity, and accuracy. The assay method was found to be linear from 159.0 to 793.2 microg/mL (3.2 to 15.9 microg injected). All validation parameters were within the acceptable range. The developed method was successfully applied to estimate the amount of methocarbamol in a veterinary injection.
Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Metocarbamol/análisis , Drogas Veterinarias/análisis , Técnicas de Química Analítica/métodos , Química Farmacéutica/métodos , Furanos/análisis , Metanol/química , Modelos Químicos , Relajantes Musculares Centrales/análisis , Reproducibilidad de los Resultados , Rayos Ultravioleta , Agua/químicaRESUMEN
A simple liquid chromatographic method was developed for the estimation of azithromycin raw material and in pharmaceutical forms. The sample was chromatographed on a reverse phase C18 column and eluants monitored at a wavelength of 215 nm. The method was accurate, precise and sufficiently selective. It is applicable for its quantitation, stability and dissolution tests.