Gymnemic Acid-Phospholipid Complex: Preparation and Characterization

The aim of the present study was to prepare a gymnemic acid-phospholipid complex (GPC) formulation in attempt to enhance the lipophilicity and to characterize the new developed formulation. Gymnemic acid (GA), due to its water soluble complex and large structure, restrict permeation across biological membrane causes poor bioavailability by oral route. To improve the bioavailability and prolong its duration in body system, its phospholipid complexes were prepared by a simple and reproducible method. GPC was formulated by mechanical dispersion method. Using aqueous ethanol as a reaction medium, GA and phospholipids were resolved into the medium, after the solvent was removed under vacuum condition, GPC was formed. In this new formulation, complex formation was confirmed by carrying out by FTIR, H-1-NMR, XRD, DSC, and microscopical studies. Solubility and in vitro studies were carried out to ascertain the solubility and dissolution pattern of free and complexed GA. Content of GA in GPC was found 96.27% (w/w). FTIR, H-1 NMR, DSC and XRD data confirmed the formation of phospholipid complex. n-Octanol solubility was altered for free GA and GPC, 8.6 mu g to 137 mu g/ml. Unlike the free GA this showed a burst and rapid drug release, GPC showed sustained release at the end of 120 minutes of dissolution study in phosphate buffer. Microscopy also shows the entrapment of GA in the lipid core showing complex structure, which is supported by change in surface morphology of GA when complexed with phospholipid. Hence the findings demonstrate that complexing GA with phospholipids results in better n-Octanol solubility, enhance lipophilicity, and altered physicochemical profile compared to free GA which can lead to improved biological effects.