Development and Evaluation of Solubility Enhanced Tablets Containing Poorly Soluble Drug Telmisartan

Telmisartan is an oral anti-hypertensive drug and it comes under angiotensin-II receptor blocker. Telmisartan is highly lipophilic and practically insoluble in water and it shows low dissolution profile and poor absorption. The solubility of telmisartan in aqueous solution is strongly pH dependent. In order to improve the solubility and dissolution rate of telmisartan, ten different formulations were prepared by changing the concentration of NaOH and PVP K-30. The solubility enhanced telmisartan tablets were prepared by wet granulation method using NaOH as alkalizer, PVP K-30 as binder (acidic), sodium starch glycolate as super disintegrant and microcrystalline cellulose as diluents. Different formulations were tested for physical inspection, thickness, uniformity of weight, hardness, friability, disintegration time, dissolution, assay, pH. Among them, formulation having concentration of 2.66% NaOH showed the best result (drug release 94.74% in 1 hour) comparing with other formulations. Telmisartan tablet showed high dissolution at high pH and dissolution was decreased with increased in concentration of binder (hardness).