Biopharmaceutical and Pharmacodynamic Characteri-stics of Telmisartan Oral Disintegrating Films

This research work was aimed to develop the telmisartan fast dissolving films. Fast dissolving films allow rapid drug dissolution in the oral cavity and thereby bypass the first pass metabolism. Solid dispersions of telmisartan using natural polymers such as hupu gum (HG), guar gum (GG) and xanthan gum (XG) were prepared by kneading technique and the optimized solid dispersion was exploited in the development of rapidly dissolving film. Telmisartan films were prepared by solvent casting method using different grades of HPMC (E5, 50 cps and K4M). Six formulations (FT1-FT6) of telmisartan films were prepared and evaluated for their physical characteristics such as thickness, tensile strength, percentage elongation, weight variation, folding endurance, drug content uniformity and surface pH and gave satisfactory results. The compatibility of the drug in the formulation was confirmed by FTIR and DSC studies. The formulations were subjected to disintegration, in vitro drug release and pharmacodynamic studies on spontaneous hypertensive rats (SHR). Amongst the formulations of FT1-FT6, FT6 was found as best formulation which contains HPMC E5 and telmisartan solid dispersion with guar gum at weight ratio of 1:2 and showed excellent film forming characteristics such as disintegration time at 42 sec and percentage drug release 97.98% within 10 minutes. The optimized film formulation (FT6) showed excellent stability over 45 days when stored at 40°C/60% RH. The pharmacodynamic study in SHR proved that fast dissolving films of telmisartan produced a faster onset of action.