Difference spectrophotometric determination of telmisartan in tablet dosage forms
Department of Pharmaceutical Chemistry, K. L. E. S's College of Pharmacy, Belgaum-590 010, India
A R Bhat Department of Pharmaceutical Chemistry, K. L. E. S's College of Pharmacy, Belgaum-590 010 India E-mail: [email protected]
Difference spectrophotometric method was developed for the estimation of telmisartan in bulk drug and in pharmaceutical formulations. Telmisartan exists in two different forms in acidic and basic mediums that differ in their UV spectra. Difference spectrum, obtained by keeping telmisartan in 0.01 N NaOH in reference cell and telmisartan in 0.01 N HNO 3 in sample cell, showed two characteristic peaks at 295 nm and 327 nm with positive and negative absorbance respectively. Difference of absorbance between these two maxima was calculated to find out the amplitude, which was plotted against concentration. The method was found to be linear in the range of 2-12 μg/ml.