Hydrogel based biodegradable enteric coated alginate beads for colon targeted drug delivery of embelin.

Abstract

attempt is made to develop a sustained release multi particulate dosage form containing herbal molecule. Embelin, a well-proven anthelmentic from herbal origin was formulated in to gel beads of sodium alginate. A 23 full factorial design has been adopted for optimization of crosslinked sodium alginate beads containing embelin. Sodium alginate (10% w/v) was used as a polymer. Based on preliminary studies, the constraints of independent variables X1 (concentration of cross linking agent), X2 (type of hardening agent) and X3 (drying temperature for beads) have been fixed. The dependent variable that has been selected was Y1 (time taken for 80% drug release from beads, T80). The application of factorial design gave systematic approach in optimization on formulation variables. Concentration of cross linking agent (10% and 20% CaCl2) and type of hardening agent (Isopropyl alcohol and Glutaraldehyde) were found to be effective in controlling the gel bead size and T80. The drug release was found to follow Korsmeyer model of diffusion. A USP dissolution guideline, similarity factor f2 for drug release from gel beads with and without colonic fluid showed dissimilarity in drug release pattern. Further, optimized gel beads were film coated with HPMC phthalate to prevent the early release of embelin in upper GI tract and allowing majority of drug to release in lower intestine.