Related Experiment Video
Updated: May 28, 2026

Sustained Administration of β-cell Mitogens to Intact Mouse Islets Ex Vivo Using Biodegradable Poly(lactic-co-glycolic acid) Microspheres
Published on: November 5, 2016
Effect of PLGA hydrophilia on the drug release and the hypoglucemic activity of different insulin-loaded PLGA
C Presmanes1, L de Miguel, R Espada
1Instituto de Farmacia Industrial, Facultad de Farmacia, Universidad Complutense de Madrid, Plaza Ramón y Cajal sn 28040, Spain.
Abstract:
The effects of viscosity and hydrophilic characteristics of different PLGA polymers on the microencapsulation of insulin have been studied in vitro and in vivo after subcutaneous administration to hyperglycemic rats. Hydrophilic PLGA polymers produced a higher burst effect than the hydrophobic ones. Moreover, an incomplete insulin release was observed with the hydrophilic PLGA polymers in comparison with the hydrophobic ones. An explanation for that incomplete release can be the development of polymer-insulin interactions associated to the polymer hydrophilic/hydrophobic character, as detected by DSC analysis. Differences in the release rate of microsphere formulations lead to differences in the hypoglycemic action and the weight of animals. Hydrophobic PLGA was able to prolong the hypoglycemic action up to 4 weeks which is at least double than that obtained with hydrophilic PLGA of a similar viscosity. Comparing insulin microspheres with an immediate release formulation, microspheres can increase insulin relative bioavailability up to four times.
Related Concept Videos
Oral Hypoglycemic Agents: Glinides
Glucagon-like Receptor Agonists
GLP-1, when administered in high doses intravenously, triggers insulin secretion, inhibits glucagon release, slows gastric emptying, reduces food intake, and restores normal insulin secretion. However, its rapid inactivation by the...
Oral Hypoglycemic Agents: α-Glucosidase Inhibitors
Acarbose and miglitol are typically...
Dipeptidyl Peptidase 4 Inhibitors
Insulin Formulations: Types and Delivery
Short-acting insulins are divided into rapid-acting...
Bioavailability Enhancement: Drug Stability Enhancement and GI Retention

