Thermal,infrared and Solubility Study of Repaglinide Solid Dispersion: Transforming Crystalline Repaglinide into Amorphous State by Adding Polymers for Enhancing Bioavailability

Solid dispersion techniques have been widely used as an effective method for enhancing the dissolution rate and bioavailability of poorly water soluble drugs. Current study was conducted to reveal the possibility of preparing repaglinide solid dispersions with improved aqueous solubility and dissolution rate, which will solve the difficulties in the development of pharmaceutical dosage forms of poorly water soluble drugs due to their limited water solubility, slow dissolution rate and low bioavailability. Repaglinide solid dispersion was prepared considering different variable factors: solvent variation (methanol, ethanol), polymer variation (HPMC, HPC, poloxomer, povidone K 12, povidone K 30), diluent variation (avicel, microcellac, aerosil, cross carmellose sodium, povidone VA 64, kollidon CL, talc), Drug load variation, effect of PEG 6000 content and drug release profile for different formulations was studied. Infrared spectroscopy and Thermal analysis by differential scanning calorimeter were studied. The results showed that the incorporation of different polymers transforms crystalline repaglinide into amorphous state, thus increasing its solubility and dissolution rate.