Physicomechanical properties and release characteristics of ketorolac tromethamine from chitosan films: Effect of inclusion of different polyols plasticizers

Abstract

The film-forming ability of chitosan polymer loaded with ketorolac tromethamine (KT) was evaluated. Films were prepared by a casting/solvent evaporation technique from plasticizer - free and plasticizer containing aqueous solutions. Glycerol, sorbitol, and 1-erythritol were used as plasticizers. Solid state of the films was studied by powder X-ray diffractometry (PXRD), and differential scanning calorimetry (DSC). The plasticizing efficiency was evaluated by measuring the physicomechanical properties as modulus of elasticity, tensile strength, percent of elongation and swelling ratio. The medicated films - plasticized or free - were clear and colorless. A plasticizer concentration of 20% (w/w of polymer weight) was sufficient to obtain flexible films with all tested samples. X-ray diffration patterns and DSC thermograms indicated an amorphous state of the films independent on the type of the plasticizer used. The results have showed that, incorporation of different polyols as plasticizers improves the consistency and the physicomechanical properties of the films. The plasticizers effect was dependant on the hydrophilicity and chemical structure of both plasticizer and polymer. The release profile of the drug was also significantly increased by addition of polyols as plasticizers. Moreover, the drug release pattern was found to follow Higuchi-diffusion model.