dissolution enhancement

Pioglitazone HCl is an antidiabetic drug in thiazolidinediones group and it improves insulin sensitivity in insulin resistant patients. The drug has low solubility in biological fluid, lead to the poor bioavailability after oral administration. The present study aims at enhancement of dissolution profile of Pioglitazone HCl using Hupu gum (HG) and modified Hupu gum (MHG) as carriers by solid dispersion technique. MHG was prepared by heating at different temperature. The HG and MHG were characterized for viscosity, swelling index and water retention capacity.  Solid dispersion was prepared by cogrinding method using HG and MHG in the ratio 1:1 and 1:2 respectively. The solubility data shows that solubility of Pioglitazone HCl is increases with HG and found high in MHG. The FTIR and XRD study was carried out. The X-Ray diffraction study shown crystalline nature of pure drug, which was converted into amorphous form in solid dispersion. The optimized formulation shows the higher in vitro drug release (93.49 %) within 120 min and also it shows higher absorption against pure Pioglitazone HCl. From this study it concludes that MHG could be novel approach useful as a carrier with in enhancing solubility in solid dispersion.

Solubility is the phenomenon of dissolution of solid in liquid phase to give a homogenous system. Solubility is one of the important parameter to achieve desired concentration of drug in systemic circulation for pharmacological response to be shown. Poorly water soluble drugs often require high doses in order to reach therapeutic plasma concentrations after oral administration. Low aqueous solubility is the major problem encountered with formulation development of new chemical entities. Any drug to be absorbed must be present in the form of an aqueous solution at the site of absorption. The ability to increase aqueous solubility can thus be a valuable aid to increasing efficiency and/or reducing side effects for certain drugs. This is true for parenterally, topically and orally administered solutions. The solubility of drugs is defined according to (bio-pharmaceutical classification system) BCS classification system which divides drugs to different class according to its solubility. Solid dispersion is defined as dispersion of one or more active ingredients in an inert carrier or matrix known as solid dispersion. Solid dispersion reduces the particle size and changes the micro environment of the drug particle, increases the rate of dissolution and absorption and thus changes the biopharmaceutical properties of poorly water soluble drugs. The solid dispersion method, by which a drug is dispersed in a carrier to make it amorphous, is one of the pharmaceutical approaches most commonly employed to enhance bioavailability of poorly water soluble drugs. Various pharmaceutical approaches for the preparation of SDs, including co-precipitation, lyophilization, spray drying, solvent evaporation, fusion and powder mixing methods, have been reported. It’s a new and efficient technique to improve the solubility of poorly soluble drugs.