INSIGHTS INTO PARKIA BIGLOBOSA SOLID DISPERSIONS OF DICLOFENAC FORMULATED BY KNEADING METHOD

Abstract

Solid dispersion is widely utilized to promote the dissolution rate of molecules that are poorly aqueous soluble. This study aimed at enhancing the rate of dissolution and solubility of diclofenac sodium by utilizing solid dispersions prepared with Parkia biglobosa based - polymeric carriers. A phase solubility study was conducted to investigate the capacity of the polymers to improve the drug's solubility. Solid dispersions of Parkia biglobosa mucilage, modified Parkia biglobosa mucilage, and polyvinylpyrrolidone (PVP) at different drug to polymer ratios of 1:1, 1:2, and 1:3 were prepared by the kneading technique. The percentage yield, encapsulation efficiency, and solubility at pH 7.4 of the prepared solid dispersions were evaluated. Differential scanning calorimetry (DSC), X-ray diffraction, and Fourier transform infrared spectroscopy (FTIR) were used to characterize the formulations. The release rate of the encapsulated solid dispersions was also examined. At room temperature, the aqueous solubility of pure diclofenac sodium was found to be 18.64mg/ml. Diclofenac sodium solubility was increased by 1.8 and 2.6 folds with 0.5% Parkia biglobosa polymeric carrier and modified Parkia biglobosa polymeric carrier, respectively. The percentage yield ranged from about 66 to 97%. None of the formulations exhibited an encapsulation efficiency less than 75 %. The modified Parkia biglobosa polymeric based - solid dispersions all released over 95% of the drug within 30 minutes. The Parkia biglobosa polymeric based - solid dispersions prepared by the kneading method enhanced the solubility and dissolution rate of diclofenac sodium.