Abstract

Background: Metformin Hydrochloride (MH) is an oral anti-hyperglycemic agent belonging to the biguanide class of drugs.

Objective: The present study involves the formulation and evaluation of gastro-retentive floating microparticles containing MH as a model drug for the prolongation of absorption time.

Methods: Three levels of a three-factor, Box-Behnken design were used to evaluate the critical formulation variables. Microparticles were prepared using a water-in-oil-in-water double-emulsion solvent evaporation method and examined in terms of production yield, particle size, entrapment efficiency, floating ability, morphology, FTIR (Fourier transform infrared spectroscopy), and in vitro drug release.

Results: The optimum conditions for preparing MH microparticles were predicted to be the content of ethyl cellulose content (150 mg),poly (ε-caprolactone) (150 mg), and polyvinyl alcohol (1%w/v).The optimized MH microparticles were found to be spherical with a mean size of 350.2 μm. Entrapment efficiency was 58.62% for microparticles. 63.94% of microparticles showed floating properties. The FTIR analysis confirmed no chemical linkage between microparticle components. in vitro release study showed a controlled release for up to 8h.

Conclusion: These results demonstrated that MH microparticles, as a drug delivery system, may be useful to achieve a controlled drug release profile suitable for oral administration and may help to reduce the dose of the drug and to improve patient compliance.

Keywords: Ethyl cellulose, gastro-retentive, metformin hydrochloride, microparticles, oral, poly (ε-caprolactone).

Graphical Abstract