Oral delivery of quercetin to diabetic animals using novel pH responsive carboxypropionylated chitosan/alginate microparticlesElectronic supplementary information (ESI) available. See DOI: 10.1039/c6ra12491g

This study aims at the development of efficient, biocompatible, biodegradable and bio-safe polymeric carriers for investigating the pharmaceutical potentialities of bioflavonoid quercetin in antidiabetic research. In this article, two cost effective polymers, sodium alginate and a modified chitosan derivative (succinyl chitosan) were used for encapsulating quercetin through ionic crosslinking. In vitro biophysical characterizations like Fourier Transforms Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), swelling index, drug entrapment and loading efficiency were investigated. The prepared micro-formulations could efficiently encapsulate 94% quercetin and showed pH sensitive and self-sustained release of encapsulated quercetin, protecting it from the harsh environment and enzymatic deactivation in the gastrointestinal tract. An in vivo pharmacological study revealed a pronounced hypoglycemia effect in a diabetic rat model after peroral delivery of the quercetin microparticles in comparison to free quercetin. No acute systemic toxicity is evident following its oral administration in rats, ensuring it as an efficient carrier for oral quercetin carrier system in animal models. Schematic diagram showing the formation of bioflavonoid quercetin loaded succinyl chitosan/alginate microparticles and its hypoglycaemic effect after oral feeding in diabetic rat model.