Development of metformin loaded novel drug delivery systems and in vitro and in vivo evaluation for oral route

Type 2 diabetes mellitus is one of the most prevalent metabolic diseases worldwide. Metformin HCl is the first-line oral antihyperglycemic agent for its treatment. Due to Metformin's pharmacokinetic properties (bioavailability 50-60%; plasma half-life 1.5-4 hours), high doses (0.5-2 g/day) are required. Metformin has been used for over 70 years in the treatment of type 2 diabetes, and numerous formulation studies have been conducted to improve its therapeutic characteristics, such as increasing its bioavailability to reduce the dose and frequency of administration. This study was designed to develop new drug delivery systems containing Metformin HCl and to enhance the bioavailability of the active substance, thereby reducing the dosing frequency and administered dose. To this end, inclusion complexes were produced by the lyophilization method using various cyclodextrins; inclusion complexes coated with Poly [methyl vinyl ether-alt-maleic anhydride], and microparticles were produced using the spray-drying method with Eudragit® FS 100 and Poly [methyl vinyl ether-alt-maleic anhydride]. In vitro characterizations, such as DSC FTIR 1H-NMR, particle size and zeta potential, quantitative determination, release, and release kinetics, as well as in vivo pharmacodynamic studies were performed. The in vivo results indicated that the microparticles developed with Eudragit® FS 100, coded F2, were as effective as pure Metformin HCl.