The development of expandable films based on starch and chitosan for stomach-specific delivery of quercetin solid dispersions

Abstract

Expandable films for stomach-specific delivery were developed to release quercetin, a flavonoid with in vivo gastroprotective effects, in a prolonged release fashion. We found that a solid dispersion containing quercetin and the hydrophilic polymers polyvinylpyrrolidone (PVP K30) at a 1:8 w/w ratio had approximately 1400-fold enhanced solubility (27.84 mg/mL). The quercetin solid dispersions were loaded into expandable starch/chitosan films by solvent casting method, which combined chitosan with various types of starch (pre-gelatinized maize starch, glutinous rice starch, and rice starch). We found that using pre-gelatinized maize starch-based film led to the optimized formulation. During an 8-h exposure to simulated stomach fluid, the formulation could unfold, swell, and release 80% of contained quercetin sustainably. Compared to indomethacin, the quercetin-loaded films exhibited a similar anti-inflammatory effect against RAW 264.7 macrophage cells in a dose-dependent manner. The obtained quercetin expandable films are promising as a stomach-specific delivery system.