Abstract

SIMULTANEOUS ESTIMATION OF CILNIDIPINE AND OLMESARTAN MEDOXOMIL IN BULK AND COMBINED TABLET DOSAGE FORM BY UV-SPECTROPHOTOMETRIC METHODS

*Rashmi D. R, Poornima A. N, Kavitha N. V, Soumya B. A.

ABSTRACT

Two simple, accurate, rapid and precise UV Spectrophotometric methods have been developed for simultaneous estimation of Cilnidipine (CIL) and Olmesartan medoxomil (OLM) in bulk and combined tablet dosage form. The methods employed were (A) Simultaneous equation and (B) Q-absorbance ratio method. In method 1, both the drugs exhibit good linearity over the concentration range of 1-5 μg/ml and 2-10 μg/ml CILNIDIPINE and OLMESARTAN MEDOXOMIL at 240nm (r2 =0.9999 and 0.9998 respectively) and 210nm (r2 =0.9998 and 0.9999 respectively) wavelengths respectively. Method B, involves the formation of Q-absorbance equation using the absorptivity values at 285nm (isoabsorptive point) (r2 =0.9998 and 0.9998 respectively) and 240nm (λmax of CILNIDIPINE) (r2 =0.9999 and 0.9998 respectively) and Beer’s Lambert’s law was obeyed over the concentration range of 1-5 μg/ml and 2-10 μg/ml respectively. Both the methods were found to be rapid, specific, precise and accurate. Hence these methods can be applied for routine analysis of Cilnidipine and Olmesartan medoxomil in combined dosage form without any interference by the excipients. The above methods are validated according to ICH guidelines.

Keywords: Cilnidipine, Olmesartan medoxomil, Simultaneous equation method, Q-absorbance ratio method, Validation.