Simultaneous Determination of Drotaverine Hydrochloride and Aceclofenac in Tablet Dosage Form by Spectrophotometry

Three accurate, precise, sensitive and economical procedures for simultaneous estimation of Drotaverine hydrochloride and Aceclofenac in tablet dosage form have been developed. The methods employed were Absorbance Ratio Method (I), Simultaneous equation method (Vierodt's method) (II) and First Order Derivative Spectroscopic Method (III). The first method employs 230 nm as lambda(1) (Isobestic point) and 242 nm as lambda(2) (lambda max of Drotaverine hydrochloride) for formation of equations. The second method employs estimation of a drug concentration by selecting lambda max where the absorbance of these drugs is maximum. So lambda max for Drotaverine hydrochloride and Aceclofenac is 242 nm and 273 nm respectively. The third method is based on first order derivative spectroscopy. Wavelengths 250 nm and 226 nm were selected for the estimation of the Drotaverine hydrochloride and Aceclofenac respectively. Both the drugs obey Beer's law in the concentration range 10-50 mu g mL(-1). The results of analysis have been validated statistically and by recovery studies.