A Spectrophotometric Approach for Estimating Nimodipine by Oxidative-Coupling Reaction with 4-Aminoantipyrine in its Tablet and Biological Fluids

This study involves the development of a speedy, artless, selective and precise spectrophotometric methodology for the determination of nimodipine in the aqueous medium. The proposed approach was dependent on the oxidation and coupling reaction of nimodipine with 4-aminoantipyrine using KIO3 as an oxidizing agent. A yellow-brown product was fashioned at room temperature which gave a band with maximum absorption at 464 nm. Calibration plot was linear and adheres to Beer's law within the concentration range 1.0- 35 μg/ml with an excellent coefficient of determination (R2=0.9992). The values of molar absorptivity and Sandell's sensitivity were planned and established to be in the consequence of 1.2679x104 l/mol.cm. and 0.033 μg/cm2, correspondingly. The mole ratio of the achieved product has been measured between nimodipine and 4-aminoantipyrine was evaluated to be 1:1. The detection limit (LOD) and quantitation limit (LOQ) were expected and found to be 0.01774 and 0.05914 μg/ml, correspondingly. The recoveries percentage were obtained in the range 97.38%-103.61% while, the precision (RSD) was in the range 0.96%-3.18% depending on the concentration level. The recommended approach was applied successfully to estimate nimodipine in its tablet and in the biological fluids, no intrusions were noticed from the shared excipients additives present in the commercial pharmaceutical formulation.