Design of porous Eudragit L beads for floating drug delivery by wax removal technique.

The aim of this study was to design porous matrix beads for floating drug delivery using enteric polymer, Eudragit L and various amounts of waxes (0, 0.1, 0.5, 1, 2 and 3% w/w). In this study, wax containing cetyl alcohol and white petrolatum was utilized to produce pores using a wax removal technique. To prepare the beads, Eudragit L, metronidazole and wax were dissolved in acetone and then extruded into dichloromethane. The effect of the amount of wax on the floating and drug release behavior of the Eudragit L beads was determined. After the extruded product was immersed in dichloromethane, wax dissolved out from the formed beads, resulting in a porous structure. The prepared beads could float in simulated gastric fluid for more than 10 hours. Different amounts of wax had an effect on the drug release. We found that when the percentage of wax increased, the drug release was higher while the beads remained floating. The results suggest that Eudragit L beads could be used as a carrier for an intragastric floating drug delivery system.