Abstract: 
The purpose of this study was to formulate novel mucoadhesive Eudragit microspheres by emulsification-coacervation technique for oral insulin delivery and evaluate the effect of polymer concentration on the anti-diabetic property of the entrapped drug. Mucoadhesive insulin-loaded microspheres containing magnesium stearate and varying proportions of Eudragit® RL 100 were prepared by emulsification-coacervation technique and evaluated for physicochemical performance and in vivo hypoglycemic effect in alloxan-induced diabetic rats after oral administration. Stable, spherical, brownish, discrete, free flowing and mucoadhesive insulin-loaded microspheres with size range (14.20±0.30– 19.80±0.60 µm) and loading efficiency (74.55 ± 1.05 – 75.90 ± 1.94 %) were formed. Reduction in the blood glucose level by the orally administered insulin loaded microspheres, which was significantly (p ≤ 0.05) higher than subcutaneous insulin and oral insulin solution, indicates that the former could be effective alternative for oral delivery of insulin. This study has shown that oral delivery of insulin for effective control of blood glucose could be possible using Eudragit® RL100 entrapped microspheres prepared by emulsification technique.

Keywords: Blood Glucose Reduction, Insulin, Oral Administration, Microspheres, Eudragit® RL 100.