SOLUBILITY IMPROVEMENT OF TELMISARTAN BY COCRYSTALLIZATION WITH CITRIC ACID

Crystal engineering of cocrystals promises a new approach for the development of suitable solid phase when the solubility of API is compromised. Cocrystals are an emerging solid-state form to change physicochemical and biopharmaceutical drug properties. A cocrystal is defined as a stoichiometric hydrogen-bonded complex in the solid state between the active drug species and a suitable coformer molecule that is safe for human consumption. In the present work, cocrystal of telmisartan has been prepared with citric acid. The TEL-CA cocrystal prepared by fast evaporation technique was initially characterized using DSC and FTIR studies. The PXRD pattern of the cocrystal was completely different from that of drug and coformer. The crystal structure determined using Material Studio software (Accelrys) showed triclinic symmetry with P1 space group. TEL-CA cocrystal forms a hetersynthon involving the amine group of telmisartan and carboxylic acid group of citric acid. The equilibrium solubility and intrinsic dissolution rate of cocrystal showed improvement in solubility as compared to pure drug. The pharmacokinetic parameters also showed a two fold increase in bioavailability of drug in cocrystal.