Formulation and In-vitro-in-vivo evaluation of alginate-chitosan microspheres of glipizide by ionic gelation method

Abstract

Objective: This work is aimed to formulate and evaluate alginate-chitosan microspheres of glipizide for the effective use in the treatment of diabetes. Methods: Sustained release (SR) microspheres were prepared by gentle mixing of polymers in water with the drug by agitation. The polymers used were sodium alginate and chitosan, which was extruded into 5% calcium chloride solution to produce microspheres by ionic gelation method. Results: Single unit dosage form of glipizide causes gastric irritation. When converted into the multiple unit dosage forms, it will release the drug evenly throughout the stomach causing suppression of irritation. The aim of the study was to formulate and evaluate alginate-chitosan microspheres, for SR of the chosen drug. The particle size of microspheres was in the range of 200-500 µ, maximum mucoadhesive property observed was 88.2±0.50% for formulation GCS7, maximum swelling index was 27.0% for GCS7, and the maximum entrapment was 89.1±0.28% for GCS6 formulation. It showed better in-vitro release between 80% and 90% for GCS1 and GCS2 formulation and in formulation GCS3, 50-60% reduction in plasma glucose level than conventional dosage forms when tested in-vivo. The work also aims to study various parameters affecting the behavior of microspheres in oral dosage form. Conclusion: Drugs with short half life that are absorbed from the gastrointestinal tract (GIT) are eliminated rapidly from the blood flow. To avoid this, the oral SR was developed as this formulation released the drug slowly into the GIT and maintained a stable drug concentration in the serum for a longer duration of time.