High Performance Liquid Chromatography

The present study describes the development and subsequent validation of simultaneous determination of [Levamisole HCL (І) and Closantel Sodium (П) ‘A’] and [Fenbendazole (III) and Rafoxanide (ІV) ‘B’] in two separated mixtures ‘A & B’, using isocratic RP-HPLC and TLC-densitometric techniques. In the HPLC technique; ‘agilent eclipse XDB-C8 and thermo BDS-C18 (250 x 4.6 mm) 5 µm columns’, ‘with a flow rate of 1.5 ml and 2.0 ml.min-1’, ‘acetonitrile: 0.02M potassium dihydrogen orthophosphate buffer (60:40, v/v) and acetonitrile: 0.02M ammonium formate (60:40, v/v) as a mobile phase’ and UV measurement at ‘220 and 290 nm’ were used for the studied mixtures ‘A and B’, respectively. While in TLC-densitometric technique; silica gel F254 aluminum sheets, ‘n-butyl acetate: methanol: ammonia 13.5M (10: 1: 0.1, v/v) and ethyl acetate: toluene: methanol: ammonia (4: 2.5: 2.5: 1, v/v) as developing systems’ and UV measurement at ‘240 and "292 and 284 nm"’ were used for the studied mixtures ‘A and B’, respectively. The utilized chromatographic methods were validated according to the International Conference on Harmonization (ICH) guidelines and successfully applied for determination of the studied drugs in pure form, in laboratory prepared mixtures in pharmaceutical formulations with good extraction recoveries. All the results were statistically compared with the pharmacopeial and manufacturing methods for ‘I, II and III’ and ‘IV’, respectively, where there is no significant differences were found. The developed methods were satisfactorily applied to analysis of the investigated drugs and proved to be specific and accurate for quality control of them in pharmaceutical formulations.