Spectrophotometric determination of cyclizine hydrochloride in pure and pharmaceutical preparations

A sensitive and simple spectrophotometric method for the estimation of cyclizine hydrochloride in both pure form and its pharmaceutical formulation is described. The method is based on the interaction of cyclizine hydrochloride with dichloronitrobenzene in alkaline media. Absorbance of the resulting yellowish orange complex is measured at 430 nm and is stable for more than 24 hours. The reaction obeys Beer's Law from 0.01 to 2.5 mg/10ml of cyclizine hydrochloride. Molar absorptivity is 0.2909 x 104 mol/sup -1/cm/sup -1/ and the relative standard deviation is 0.72%. Analytical data for determination of the pure compound is presented along with the application of the proposed method to the analysis of some pharmaceutical formulation. The method is reproducible and selective for cyclizine hydrochloride. The common excipients used as additives in pharmaceuticals do not interfere and the quantitative assessments of tolerable amount of other drugs not interfering are also studied. The results compare favourably with those of official procedures. (author)