Abstract :
Telmisartan (TEL) is a class of angiotensin receptor blocker, used in the treatment of hypertension. The poor
solubility and dissolution rate of drug leads to its limited bioavailability (< 50%). The aim of this study was to
improve the solubility and dissolution rate of TEL using spherical agglomeration technique. Quasi emulsion solvent
diffusion (QESD) and simple spherical agglomeration (SA) techniques have been selected, utilized and compared
for their effectiveness in improving the solubility and dissolution rate. Based on drugs solubility N, N dimethyl
formamide (DMF), chloroform and water were selected as good solvent, bridging liquid and poor solvent
respectively for spherical agglomeration. Optimization of all possible parameters for favourable spherical
crystallization was done successfully. Results indicated that, agglomerates obtained by QESD technique showed
better improvement in solubility (2.89 and 2.30 folds in 0.1N HCl and 7.5 pH phosphate buffer respectively) and
dissolution rate (2.81 fold) compared with pure drug. Results of FTIR showed no interaction between the drug and
solvent, XRD patterns showed partial amorphization of drug and SEM photographs confirmed the spherical shape
and microscopic crevices on the surface leads to better wettability. Thus, QESD technique is less expensive and
simple technique for improving the solubility and dissolution rate of TEL.
Keyword :
Telmisartan, Spherical Agglomerates, Solubility, Dissolution Rate.