A NOVEL RP-HPLC METHOD FOR SIMULTANEOUS DETERMINATION OF DICYCLOMINE AND ETHYL MORPHINE IN BULK AND PHARMACEUTICAL FORMULATION

The present study was designed to develop and validate a simple, sensitive, precise and accurate RP-HPLC method for simultaneous estimation of dicyclomine and ethylmorphine in bulk and tablet dosage form. The chromatographic separation was achieved on Discovery C₁₈ column (250 × 4.6 mm, 5 µm) as stationary phase with a mobile phase of water (pH 5.4 adjusted with orthophosphoric acid): acetonitrile (40:60 v/v) at a flow rate of 1 ml/min and PDA detection at 215 nm. The proposed method was validated for system suitability, specificity, linearity, accuracy, precision, LOD, LOQ, and robustness as per ICH guidelines. The retention times of dicyclomine and ethylmorphine were found to be 3.166 ± 0.02 and 4.204 ± 0.19 min respectively. The calibration curves were linear in the concentration range of 50% to 150% of the working concentration (r²=0.999) for both the drugs in a binary mixture. The accuracy was found to be 98.61 % and 99.24 % for dicyclomine and ethylmorphine respectively. The LOD was found to be 0.05 µg/ml, and 0.20 µg/ml and LOQ were found to be 0.17 µg/ml and 0.62 µg/ml for dicyclomine and ethylmorphine respectively. The percentage recoveries for both drugs were in the range of 98-101%. Hence the proposed RP-HPLC method can be used in routine analysis of tablets containing dicyclomine and ethylmorphine.