Sensitive Spectrophotometric Methods for the Determination of Nicardipine in Pharamaceuticals Using Bromothymol Blue and Methyl

Simple, sensitive and rapid spectrophotometric methods are developed for the determination of Nicardipine in pharmaceutical formulations. Method A is based on the extractive spectrophotometry and the final color developed is due to ion association complex formation with Bromothymol blue (BTB) at PH 3.7 resulting in the formation of a yellow color solution that exhibited maximum absorption at wavelength 380nm. Method B is based on the yellow color developed which is due to ion association complex between methyl orange (MO) at PH 3.7 and nicardipine that exhibited maximum absorption at a wave length of 430nm. Both ion association complexes are extracted into chloroform and Beers law is obeyed over the concentration ranges 1.0-10.0 gml-1 and 2.0-10.0 gml-1 for methods A and B respectively. Both the methods have been successfully applied for the assay of the drug in pharmaceutical formulations. There is No interference was observed from common pharmaceutical adjuvants. The reliability and the performance of the proposed methods are established by point and interval hypothesis tests and through recovery studies.