Development and Validation of UV Spectrophotometric Methods for Simultaneous Estimation of Amlodipine Besylate and Theophylline

The present study describes simple, specific, sensitive, rapid and economical U.V. spectrophotometric methods for simultaneous estimation of amlodipine besylate and theophylline. The absorbance maxima of the drug were found to be239 nm and 272 nm respectively. Method I is based on formation and solving of simultaneous equation known as Vierodt’s method. Method II is based on principle of Q-analysis known as absorbance ratio method. Beer’s law obeyed in concentration range of 5-30 μg/ml having regression line equation y = 0.041x + 0.017 and y = 0.064x + 0.052 with correlation coefficient 0.999 and.0.997 of amlodipine besylate and theophylline respectively. Different parameter such as linearity, precision, LOD and LOQ, slope and standard deviation were used for validation in both method.