UV SPECTROPHOTOMETRIC ABSORPTION CORRECTION METHOD FOR SIMULTANEOUS ESTIMATION OF OLMESA RTAN MEDOXOMIL, AMLODIPINE BESYLATE AND HYDROCHLOROTHIAZIDE IN COMBINED TABLET DOSAGE FORM

A simple, accurate, precise, economical and validated uv spectrometric absorption correction method was developed for olmesartan, medoxomil amlodipine besylate and hydrochlorothiazide in bulk and its dosage form. The stock solutions were prepared in methanol followed by further dilutions with double distilled water. The λmax for olmesartan, amlodipine besylate and hydrochlorothiazide were 256.5 nm, 362 nm and 316 nm, respectively. Beer's law was obeyed in the concentration range of 3-18 μg/mL, 1- 6μg/mL and 2-12 μg/mL, respectively. The method was validated by following the analytical performance parameters suggested by the ICH Guidelines. The percentage assay in commercial formulation was found to be in the range olmesartan 100.06%, amlodipine 99.17% and hydrochlorothiazide 100.14% by the proposed method. The method was validated with respect to linearity, precision and accuracy. recovery was found to be in the range of olmesartan 99.65%,amlodipine 99.97% and hydrochlorothiazide 99.81% by absorbance corrected method. The high recovery and low coefficients of variation conforms the suitability of the method for simultaneous analysis of three drugs in combined tablets.