Enhanced Dissolution of Repaglinide: SMEDDS Formulation and In-vitro Evaluation

Repaglinide a BCS class II poorly water soluble drug was formulated into lipid drug delivery system of self microemulsifying delivery system (SMEDDS). Surfactants and oil was selected based on solubility studies were further screened for their efficiency in formulation. Sesame oil was used as oil phase with different ratios of Labrasol as surfactant and transcutol as a co-surfactant. For enhanced stability liquid SMEDDS were converted into solid SMEDDS by adsorbing onto a carrier neusilin. Various physicochemical tests were done on the formulations and the better formulations were subjected to droplet size and zeta potential. The in-vitro drug release studies and ex-vivo intestinal permeation studies were done to prove the increased dissolution and permeability. SEM and TEM studies were conducted on the formulations to prove the decreased particle size of the formulation. The physical stability of prepared microemulsions was confirmed by good optical clarity and cloud point values. The prepared formulations had droplet sizes in the range of 25 to 170nm, and zeta potential value -15.3mV. The in-vitro drug release studies have shown 98% of drug releasing in 30min and ex-vivo intestinal studies have depicted 73% of drug diffused in 6 hrs as compared to plain drug releasing 30%. Thus formulated Repaglinide SMEDDS have been proved to be efficient method of improving the dissolution and oral bioavailability of otherwise poorly soluble drug.