Commercial Telmisartan Tablets: A Comparative Evaluation with Innovator Brand Micardis

Purpose: Telmisartan is an angiotensin II receptor antagonist used in the management of hypertension. The solubility of Telmisartan in aqueous solutions is strongly pH-dependent. Five commercial tablets of telmisartan (40 and 80 mg) were compared with the reference formulation Micardis (Innovator brand of telmisartan molecule). Experimental: Dissolution tests were performed by employing USP type apparatus-II (Paddle type) at 75rpm using pH 1.2, 4.5 and 7.5 buffers as the dissolution media. The percentage cumulative release of Telmisartan was measured at 5, 10, 15, 30, 45, and 60 minutes respectively. The factor f2 of the FDA’s SUPAC Guide was applied to the qualitative determination of ‘similarity’ between pairs of dissolution profiles of Micardis and those of each investigated formulation. Results:None of the commercial brands were similar to Micardis in dissolution profile at various pH points of testing. This was observed for both the strengths. Conclusion: Micardis tablets at both the strengths showed consistently higher release at pH 4.5 and 7.5 (i.e., pH conditions relevant to the intestine) suggesting its pharmacokinetic activity could be perhaps superior to other marketed brands as it would release the drug consistently irrespective of pH.