An approach to increase the bioavailability of glipizide by self- emulsification technique

Abstract

Glipizide  is  the  first,  potent  second  generation  oral  hypoglycemic  drug  of  sulfonic  urea  class  and  is  used  in management of type II diabetes. It is one of the active ingredients used to treat diabetes. In the present work self- emulsifying drug delivery system of Glipizide was developed to treat diabetes. Self-emulsifying drug delivery system (SMEDDS) formulated to improve the oral bioavailability of lipophilic drugs. SMEDDS are isotropic mixtures of oils, surfactants and co-solvents. Pseudo-ternary phase diagrams were plotted to check the emulsification range and also to evaluate the effect of Glipizide on the emulsification behavior of the phases. The mixtures consisting of oil (oleic  acid)  with surfactant  (Tween  80), co-surfactant  (PEG  400) were  found to be optimum  formulations.  The prepared formulations were evaluated for various parameters like robustness to dilution, drug content and in-vitro dissolution. The optimized SMEDDS formulation further evaluated for particle size distribution, zeta potential, TEM were carried out to confirm the stability of the formed SMEDDS. The release data was fitted to various mathematical models to evaluate the kinetics of drug release. The drug release follows mixed order kinetics and mechanism was found to be non-Fickian diffusion. From this study it can be concluded that the formulation was found to be showing significant improvement in terms of the drug release with complete release of drug within 18 minutes. Thus, Self- emulsifying formulation of Glipizide was successfully developed.