Preparation and characterization of dual buoyant/mucoadhesive polypropylene microparticles (MPs) loaded with repaglinide (REP) for gastric drug delivery in order to augment the weak mucoadhesion in the stomach.Porous foam powder MPs were prepared using coating polymers with variable permeability (Eudragit L100, Eudragit RSPO) alone or in combination by the soaking method. Thiolated Eudragit L100 (Eudragit L100-SH) was also synthesized and tried in an attempt to enhance the mucoadhesive properties of MPs. All formulae were characterized for their yield, flow properties, particle size, encapsulation efficiency (EE %), morphology, and drug release and its mechanistics. Possible interactions inside MPs matrix were also elucidated using FTIR study. The suitability of the selected formulae for gastroretention was evaluated by in vitro buoyancy and ex-vivo mucoadhesion studies.All REP-loaded MPs demonstrated a passable powder flow, high yield values, promising floatation and mucoadhesion. Encapsulation efficiency % values were nearly tripled upon addition of Eudragit polymers. Compared to the Eudragit free REP loaded foam powder, all formula showed more sustained release features. Eudragit L100-SH was synthesized and confirmed by FTIR. Furthermore, its incorporation, alone or in combination, exhibited a significant increase in mucoadhesion strength compared to the unmodified one.Dual buoyant/mucoadhesive MPs loaded with REP encourage planning for future in-vivo performance studies for the management of diabetes
