Evaluation of crystal forms of Nateglinide

Abstract

Different physiological and formulation factors are responsible for the bioavailability of drug from the dosage form. One of the most important physical factors, which affect the bioavailability and therapeutic efficacy of drug, is the existence of active ingredients in various crystal forms having different internal structure and physical properties. The different crystal form of a drug have different physico-chemical characteristics namely crystal shape, crystal size, melting point, density, flow properties solubility pattern, dissolution characteristics and XRD pattern, though they are chemically identical. The crystal habit is an important variable in pharmaceutical manufacturing, where some factors such as the polarity of crystallization solvent and the presence of impurities in the solvent affect crystallization. Among them, solvent strongly affects the habit of crystalline materials; however the role played by solvent interactions in enhancing or inhibiting crystal growth is still not completely understood. The drug nateglinide used here is practically insoluble in water. But the water insolubility and the less bioavailability are the limitations of its effective use clinically. Keeping this in view crystal modification of nateglinide has been undertaken to improve solubility, dissolution and bioavailability. New crystals prepared by two different methods using solvents like Benzene, Ethanol and Acetone in this study to observe the effect of solvents on the development of crystal habits in the changed environment, and prepared crystals were characterized by some physico chemical techniques like melting point, UV and I.R spectroscopy, solubility and invivo dissolution studies, scanning electron microscopy, X-ray powder diffraction and DSC analysis.