Assessment of Effects of Solvents on Cocrystallization by Computational Simulation Approach.

Abstract

The sole purpose of this study is to improve the solubility and dissolution of telmisartan by cocrystallization technique and apply a computational simulation approach to assess the nature of chemical interactions between telmisartan and coformer as well as the solvent contribution to the molecules for furnishing cocrystallization. The effects of various concentrations of coformer i.e. oxalic acid on physicochemical parameters and drug release were investigated. Solubility studies suggested that cocrystallization technique with oxalic acid helps to increase the solubility of pure telmisartan of about 7 folds and drug release study revealed that telmisartan-oxalic acid cocrystals showed greater dissolution as compared to pure telmisartan. SEM study suggested that prepared telmisartan cocrystals showed rhomboid-shaped crystals with sharp edges and smooth surface. FTIR study revealed that shifting in the vibrational frequencies of C=O group of telmisartan in telmisartan- oxalic acid cocrystal indicates the formation of supra molecular hetero synthon of the cocrystal. DSC and XRD studies confirmed the formation of telmisartan-oxalic acid cocrystals. Computational simulation approach revealed that telmisartan and oxalic acid can interact with each other in the presence of methanol and water where oxalic acid can form interactions principally with the others. The interactions, thereof, may form several associations or bondings in between the drug and carrier modifying the planarity, bond energy, bond angles of both which subsequently lead to cocrystallization. So, the present research concluded that prepared telmisartan-oxalic acid cocrystal is a successful application of crystal engineering approach to improve the physicochemical properties as well as to enhance the solubility and dissolution of telmisartan.