LIQUID CHROMATOGRAPHIC TECHNIQUE FOR THE SIMULTANEOUS DETERMINATION OF SULPHAMETHOXAZOLE AND TRIMETHOPRIM IN PHARMACEUTICAL FORMULATIONS

Abstract

This paper describes the development and validation of a simple, specific, precise, and accurate Liquid Chromatographic method for the simultaneous determination of sulphamethoxazole and trimethoprim in pharmaceutical dosage forms. The chromatographic resolution was achieved with 50mM sodium phosphate buffer and acetonitrile (85:15) on a reversed phase column - Octyldecylsilane C18 column (100 x 4.6 mm, i.d., 5m) - at ambient temperature.  The flow rate through the column was 1ml/min and the UV detection was at 260nm using Agilent HPLC 1100LC System.  The mean retention times for trimethoprim and sulphamethoxazole were 2.998 and 6.205 minutes respectively. Calibration curves were rectilinear over the ranges 580 mg/L (trimethoprim) and 25400 mg/L (sulphamethoxazole).  The RSD was less than 2.61% and percentage recovery was between91.93% - 103.98% with respect to precision and accuracy.  The method has been used to analyze brands of cotrimoxazole tablets.  The percentage content of sulphamethoxazole and trimethoprim were found to be comparable with BP 2002 requirement.  This method, which has a fair run time of 6 minutes, is cost effective for routine analytical work and for quality control and product monitoring.