Natural Macromolecules in the Development of Safe and Effective Gastroretentive Floating Microparticles of Metformin Hydrochloride

Abstract

Background: Metformin hydrochloride, an oral hypoglycaemic, shows better absorption from upper part of the gastric region. Natural/herbal substances have been investigated for the development of natural polymer-based drug delivery systems owing to the desirable properties like biodegradability, biocompatibility, aqueous solubility, swelling ability, easy availability and cost effectiveness. Method: Therefore, three natural macromolecules: Glycine max (soya chunks), Metroxylon sagu (sago starch) and Plantago ovata (psyllium husk) were used for developing its gastroretentive floating microparticles for expected improvement in bioavailability. The macromolecules and the prepared microparticles were evaluated for physicochemical properties, FTIR, XRPD, DSC and dug release. Result: The percent drug content was in the range of 60.353 ± 1.25 to 92.682 ± 2.47 % for all the microparticles. All the formulations showed good swelling and floating properties (the formulation prepared with P. ovata showed the best swelling and in vitro floatability). The FTIR studies showed that the herbal carriers were compatible with the drug. XRD and DSC studies showed a transition in the physical state of the drug in the formulations from crystalline state to amorphous state. In vitro drug release studies showed good percent cumulative drug release from all the formulations (72.13 to 87.06 % at the end of 6 hour) with non-fickian diffusion process. Conclusion: Therefore, it was concluded that the herbal macromolecules may be the potential, safe and effective carriers for improving the drug delivery of the metformin like drugs by developing, effective gastroretentive floating drug delivery systems.