Telmisartan

An accurate, precise and reproducible high performance liquid chromatographic method was developed for quantitative estimation of telmisartan in bulk drug samples and tablet dosage forms. Chromatographic separation of the drug was achieved on a Kromasil C18 column (150 x 4.6 mm; 5µ) using a mixture of phosphate buffer (pH 4.0) and acetonitrile (40:60 v/v) as the mobile phase at a flow rate of 1.0 mL/min. Under optimized conditions, the retention time of the drug was found to be 2.887 min. Good detecting sensitivity for the analyte was observed at 224 nm. The quantitation calibration curve for the drug was linear over the range of 20-60 µg/mL. The performance of the proposed method was validated as per ICH guidelines. The method was proved to be suitable for the estimation of telmisartan in tablet dosage forms. Key words: Telmisartan, Estimation, Tablets, HPLC.

In vitro dissolution studies constitute the mainstay for evaluation of any oral dosage form and more so for a poorly water soluble drugs. Selection of appropriate dissolution medium is critical for these studies as it could have an impact on in vitro - in vivo correlations. Biorelevant media simulate the in vivo conditions in fasting and fed state and are being investigated as novel dissolution media. Telmisartan is a BCS class II drug exhibiting solubility and dissolution rate limited bioavailability. In the present study 03 marketed brands of TEL tablets were subjected to in vitro dissolution studies in biorelevant media. The results were compared with tablets prepared using binary and ternary solid dispersions of TEL with poloxamer 188 and TPGS. The marketed and formulated products displayed widely different release profiles in fasting and fed state simulated intestinal fluid. The results indicated the need to develop dissolution studies and media which will facilitate in vitro in vivo correlation studies. Key Words: Telmisartan, fasting state simulated intestinal fluid, fed state simulated intestinal fluid