Enhancing Dissolution Rates of Gliclazide via Co-crystallization with Nicotinamide

Gliclazide is a drug with poor water solubility and high permeability (BCS II), The absorption rate of this drug, when taken orally is controlled by dissolution rate in the gastrointestinal tracts. Co-crystallization method is widely used to improve the dissolution rate of this type of drug. This study aims to improve the dissolution rate of gliclazide by Co-crystallization method with nicotinamide as a coformer. Co-crystallization were prepared by solvent evaporation methods using methanol. Pure gliclazide, co-crystal gliclazide-nicotinamide in molar ratio 1:0,5, 1:1, 1:2, 1:2,5, 1:3, 1:3,5, 1:4, 1:5, and 1:7 and physical mixtures were characterized by DSC, FTIR, XRD and dissolution testing. Characterization by DSC and XRD in ratio 1:0,5, 1:1, and 1:2 showed a lower  endothermic peak of gliclazide, and decrease in the intensity of the diffraction pattern by XRD. Characterization by FTIR virtually showed no shift  of absorption peaks of gliclazide in ratio 1:0,5, 1:1, and 1:2. FTIR spectrum of cocrystal in ratio 1:7 showed a shift of absorption peaks for C=O and N-H. Results of dissolution testing for cocrystal in ratio 1:0,5, 1:3, 1:7, and physical mixture in ratio  1:7 showed higher dissolution rate than pure gliclazide. The highest of dissolution rate is cocrystal gliclazide-nicotinamide in ratio 1:7. Similarity analysis (f 2 ) showed no similarity of dissolution rate for pure gliclazide, cocrystal gliclazide-nicotinamide in ratio 1:0,5, 1:3, 1:7 and  physical mixture in ratio  1:7.