Abstract

A simple and sensitive spectrophotometric method has been developed for the determination of nimodipine in bulk and pharmaceutical dosage forms. The method is based on diazotisation of reduced nimodipine with nitrous acid followed by its coupling with β-naphthol in alkaline medium to form an orange red colored chromogen with an absorption maximum of 555 nm. Good agreement with Beer's law was found in the range of reduced nimodipine concentration of 0-10 μg/ml. The optimum reaction conditions and other analytical parameters are evaluated-The proposed method has been successfully applied to the analysis of the bulk drugs and their dosage forms. No interference was observed from talc, starch, dextrose and magnesium stearate in the proposed method. Statistical comparison of the results with those of reported method showed good agreement and indicated no significant difference in precision. This method does not require any extraction or heating.