Metformin Loaded Casein Micelles for Sustained Delivery: Formulation, Characterization and In-vitro Evaluation

Nano particle formulations, especially protein based formulations are great drug delivery systems for a targeted and sustained drug release. The Specificity lies with the receptor-ligand binding mechanism adopted by them. Metformin hydrochloride (MET) is a widely used biguanide oral antidiabetic agent, against Type II diabetes. In its free form, it suffers some shortcomings like poor oral bioavailability for its site specific absorption and frequent dosage administration requirement for its short half life. With a vision of troubleshooting these drawbacks, we developed a novel protein based, ‘casein-MET micelles’ delivery system. It is a sustained drug delivery system that involves a very simple and reliable method of using sodium caseinate for entrapping MET. These synthetic micelles were characterized by their particle size distribution, zeta potential, polydispersity index. The morphological and physicochemical characterization was done by using Scanning electron microscopy and FTIR spectroscopy, which was further validated by in-vitro drug release evaluation. This method produced very fine and stable casein-MET micelles with a uniform rod shape of average 1.2µm size. In-vitro drug release behavior of casein micelles suggests that about half of the drug is released during first 3h and 85% of the drug is released after 15h of its administration, which could be a great improvement of the existing methods.