Floating gellan-chitosan polyelectrolyte complex beads: effect of gelucires incorporation on encapsulation efficiency and drug release

The purpose of the present investigation is to study the effect of incorporation of gelucire 39/01 and 50/13 on encapsulation efficiency and release of water soluble drug (metronidazole, log P = 0.0) from floating gellan-chitosan polyelectrolyte complex (PEC) beads. Floating emulsion PEC beds were prepared in one step without using any chemical crosslinker. Briefly, an emulsion of gellan gum (GG) with gelucire 39/01 and 50/13 containing CaCO₃ and drug was extruded dropwise into low molecular weight chitosan (LMCH) solution. Beads formed instantaneously were cured for 15 min at elevated temperature (37 °C). Prepared beads showed excellent buoyancy along with significantly improved encapsulation efficiency and sustained release of metronidazole when compared to floating gellan-chitosan PEC beads prepared in the similar manner but without gelucires. Experimental data obtained from the present investigation showed that floating emulsion PEC beads may form a potential stomach site specific drug delivery system for the delivery of highly water soluble drugs with an absorption window in the upper gastrointestinal tract. Colegio de Farmacéuticos de la Provincia de Buenos Aires