Development and characterization of irbesartan co-crystals

The aim of the work was to prepare co-crystals of irbesartan (IBS), a BCS Class II drug to enhance its aqueous solubility and bioavailability. The solvent evaporation method was used to prepare co-crystals by using different co-formers and varying the drug to co-former molar ratios. Succinic acid and benzoic acid co-crystals were formed with good physicochemical properties. The solid-state characterization of co-crystals was studied by FTIR, DSC, and XRD. The co-crystals were evaluated for the saturation solubility and dissolution studies. There was a 2-fold increase in the aqueous solubility and 4-8 fold increase in dissolution rate of co-crystals. Solid state characterizations indicated there was no change in the chemical nature of the co-crystals compared to pure drug. Presence of crystalline co-former induced crystallinity to the developed co-crystals. Thus, developed co-crystals were found to be a suitable alternative to increase the solubility and dissolution rate of IBS.