RESUMO
An isocratic method for the identification and quantitation of erythromycin and related substances in enteric-coated tablet formulations using high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection at 205 nm is described. A novel method for sample preparation using a molecular weight centrifuge filter to reduce the interferences observed from polymeric tablet coating material is also presented. Erythromycin HPLC assays are best run at high pH; therefore, various polymer columns were evaluated. The resulting HPLC method that was developed has several advantages over current pharmacopeial assay methods for enteric-coated erythromycin tablets. Comparative data from both methods for the same batch of EryTab tablets are presented. The method can also be applied to various other erythromycin formulations, including particle-coated tablets, erythromycin stearate tablets, and erythromycin ethylsuccinate suspensions and fermentation broths. A C18 Polymeric column is used with a mobile phase composition of 0.02 M potassium phosphate dibasic buffer (pH 9): acetonitrile (60:40) and flow rate of 1 mL/min. This method is more sensitive, specific, and rugged than the pharmacopeial method.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Eritromicina/análise , Química Farmacêutica , Estabilidade de Medicamentos , Eritromicina/análogos & derivados , Eritromicina/química , Sensibilidade e Especificidade , Espectrofotometria Ultravioleta/métodos , Comprimidos com Revestimento EntéricoRESUMO
Cefsulodin, cefmenoxime, and cefadroxil are degraded instantaneously in aqueous sodium hypochlorite, sodium hypochlorite-detergent, or alkaline detergent solutions. These alkaline solutions are used to clean surfaces that have been exposed to the cephalosporins. The cleaned surfaces are monitored for residual drug levels (microgram) using a wet swab-dry swab technique. After extraction from the swabs, the content of the respective cephalosporin is determined in the solution by high-performance liquid chromatography. The limit of detection for each of the compounds is 0.1 microgram/ml. Recoveries from nonporous surfaces ranged from 56 to 102%.
