A Sensitive Spectrophotometric Estimation of Nimodipine in Tablets and Injection Using Phloroglucinol

A rapid, simple, and sensitive spectrophotometric method was described for the detn. of nimodipine in bulk drug, tablets and injection. The proposed method is based on the diazotization of reduced nimodipine with nitrous acid followed by coupling with phloroglucinol to form colored azo dye and showing absorption max. (λmax) at 410 nm. The formed colored azo dye is stable for about more than 2 h. The method obeyed Beer's law over the concn. range of 0-25 μg/mL and the corresponding molar absorptivity value is 1.23 × 104 L/moL/cm. The Sandell sensitivity values limits of detection (LOD) and quantification (LOQ) values were also reported for the developed method. The accuracy and precision of the method was evaluated on intra- and inter-day basis; the relative error (%RE) and the relative std. deviation (RSD) were >2.0%. All variables were optimized and the presented reaction sequence was applied to the anal. of nimodipine in bulk drug, tablets and injections. The performance of this method was evaluated in terms of Student's t-test and variance ratio F-test to find out the significance of proposed method over the ref. method. [on SciFinder(R)