Abstract

SIMULTANEOUS DETERMINATION OF BRINZOLAMIDE AND TIMOLOL MALEATE USING THREE DIFFERENT SPECTROPHOTOMETRIC METHODS

Purvi A. Shah*, Ankita S. Kadikar, Riddhi M. Katira, Kalpana G. Patel, Tejal R. Gandhi

ABSTRACT

Three simple, rapid and precise UV spectroscopic methods namely simultaneous equation (method 1), Q-absorbance ratio (method 2) and ratio first derivative (method 3) have been developed for the simultaneous determination of brinzolamide (BRZ) and timolol maleate (TM). In method 1, both the drugs exhibit good linearity over the concentration range of 5 to 30μg/ml at 254 and 294 wavelengths. Method 2 involves the formation of Q-absorbance equation using the absorptivity values at 272 nm (isoabsorptive point) and 254 nm (λmax of BRZ) and Beer’s Lambert’s law was obeyed over the concentration range of 5-30 μg/ml with regression coefficient 0.9985 and 0.9964 respectively. The third method is based on ratio first derivative spectrophotometry, and at 242.9 and at 296 nm, linear concentration range for BRZ and TM was 5 to 25 μg/ml with regression coefficient 0.9985 and 0.9944 respectively. The proposed methods were validated according to ICH guidelines for evaluation of accuracy, precision, sensitivity etc. In conclusion, the proposed methods are novel, simple, accurate, precise, sensitive, rapid and economically viable methods that do not require any prior separation procedure. The proposed three methods hold potential for simultaneous determination of BRZ and TM in ophthalmic formulation.

Keywords: Brinzolamide, Timolol maleate, Simultaneous equation method, Q-absorbance ratio method and Ratio first derivative method, validation.