Enhancement of Dissolution Rate of Irbesartan by Chitosan based Crystal Engineering Technique

The objectives of present investigations were to enhance dissolution rate of irbesartan by using chitosan and chitosan chlorhydrate and optimize an effective concentrations of both.

Cocrystals of irbesartan (IB) were prepared by solvent change technique.Chitosan solution was prepared by soaking chitosan and chitosan chlorhydrate in glacial acetic acid. A weighed amount of drug was dispersed in chitosan solution by stirring. The dispersion was added to sodium citrate solution to precipitate chitosan on drug crystals. The precipitate obtained was filtered through Whatmann No. 1 filter paper using vacuum filtration unit and dried at 45⁰ C for 24 h. The prepared cocrystals were characterized in terms of saturation solubility, drug content, infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), in vitro dissolution studies and stability studies. The considerable improvement in the dissolution rate of drug from optimized co-crystal formulation was attributed to the decreased drug crystallinity, altered surface morphology and reduction in particle size. The 0.2% chitosan and 0.4% chitosan chlorhydrate were found to be optimized concentrations for enhancement of dissolution rate of irbesartan. The technique is scalable and may prove valuable in manufacturing process in future for enhancement of dissolution of poorly water soluble drugs.