FORMULATION OF BINARY AND TERNARY MIXTURES OF POORLY WATER-SOLUBLE DRUG TELMISARTAN AND THEIR IN-VITRO EVALUATION FOR ENHANCED SOLUBILITY AND DISSOLUTION BY SOLID DISPERSION TECHNIQUE

The present study was carried out to enhance the dissolution rate of poorly water-soluble drug Telmisartan, by solid dispersion technique using different carriers and super disintegrants by solvent evaporation method. Solid dispersions were prepared with mannitol and PEG 6000 in different ratios of 1:1, 1:3 and 1:5. In-vitro dissolution profile of solid dispersion (SD) with drug and mannitol in the ratio of 1:3 (SDM2) was found to be highest among all 12 formulations. This SD was further adsorbed with Neusilin US2 to form a ternary mixture. Crospovidone was used due to its promising role in dissolution enhancement of telmisartan based on previous studies. For optimizaton of concentration of Neusilin US2 and crospovidone in solid dispersion, Central Composite Design was applied for two factors at two level which gave 13 formulations. Tablets were prepared and evaluated for physiochemical properties. Reponse surface plot and contour plot were drawn, and an optimum formulation was selected. This formulation contained 40 mg of Neusilin and 14 mg Crospovidone (CCDF4). The in-vitro dissolution studies of optimized formulation CCDF4 and marketed product was carried out in USP Type II apparatus at different time intervals of 10, 20, 30 and 45 minute at 75 rpm in phosphate buffer, pH 7.5. Solid state characterization was evaluated by FTIR. It showed that the drug was stable in different polymers used in the study. Hence, Solid dispersion technique can be sucessfully used for the improvement of the dissolution profile of Telmisartan.