Development and Validation of Three Novel UV Spectrophotometric Methods for Simultaneous Estimation of Efonidipine Hydrochloride Ethanolate and Telmisartan in Their Synthetic Mixture and Its Comparison Using ANOVA

Efonidipine hydrochloride ethanolate and telmisartan combination is used for to treat hypertension treatment and under clinical phase 4 study. It is necessary to develop suitable quality control methods for rapid and accurate determination of these drugs. Three simple, accurate, sensitive, precise and economical UV spectrophotometric methods (A, B &, and C) have been developed for simultaneous estimation of efonidipine hydrochloride ethanolate and telmisartan in their synthetic mixture. Method (A) is based on the first order derivative spectrophotometric method at zero crossing wavelength. In this method the zero crossing zero-crossing point of efonidipine hydrochloride ethanolate is 326 nm and for telmisartan is 272 nm. The linearity was obtained in the concentration range of 8-20 μg/ml for efonidipine hydrochloride ethanolate and 16-40 μg/ml for telmisartan using methanol as a solvent. Method (B) is based on absorbance correction method, method; it was performed at 347 nm for efonidipine hHydrochloride ethanolate and at 296 nm for telmisartan. Method (C) is based on dual wavelength method developed using absorbance difference at 242.5 nm and 257.5 nm for efonidipine hydrochloride ethanolate and 244.5 nm and 287 nm for telmisartan. The accuracy and precision of the methods were determined assessed and validated statistically. All the methods showed revealed good reproducibility and recovery. The three methods were compared using one way ANOVA. All methods were found to be rapid, specific, precise and accurate and these methods require no preliminary separation and found no interferences from the tablet excipients so it can be used for routine analysis of both drugs in quality control laboratories.