Chitosan-telmisartan polymeric cocrystals for improving oral absorption: In vitro and in vivo evaluation

Abstract This study describes the development of polymeric cocrystals of chitosan-telmisartan (TEL) to improve the oral bioavailability of TEL, which has poor oral solubility and bioavailability. The polymeric cocrystal was prepared using chitosan a biopolymer with the aid of sodium citrate as a salting-out agent. The cocrystals were characterized by FT-IR spectroscopy, scanning electron microscopy, differential scanning calorimeteri (DSC), thermogravimetric analysis (TGA), and powder X-ray diffraction (PXRD). The improved solubility of TEL was observed with cocrystals as compared to that of pure drug in solubility studies with phosphate buffer (pH 7.4). The in vivo pharmacokinetics properties of cocrystal were studied by an animal model using rats after a single dose oral administration. The results showed an increased plasma drug concentration ( C max ) of 1.47, μg/ml for cocrystals when compared to pure TEL with 0.96 μg/ml with one-fold increased bioavailability (F%) that is, the cocrystals increases the solubility of the drug and the paracellular drug absorption by tight junction modulation. Further the elimination constant K el resulted with higher value of about 0.0085 h −1 when compared to pure drug with0.0048 h −1 along with improved AUC (14.62 μg/ml).