Study on effect of combination of sodium alginate and xanthan gum on drug release from Tacrolimus microbeads

Tacrolimus micro beads are promising pharmaceutical dosage forms by providing sustained release drug delivery systems.The drug Tacrolimus has low bioavailability, hence to improve its bioavailability.Tacrolimus loaded microbeads were prepared by Ionotropic gelation and cross linking technique by using sodium alginate as the hydrophilic carrier in combination with xanthan gum as release modifier. Micro beads with different ratio of sodium alginate and xanthan gum were formulated and evaluated for percentage yield and Percentage of drug entrapment efficacy. An optimized batch was selected from the previous stages and four batches with same concentrations of Tacrolimus and different concentration of calcium chloride and stirring time were loaded. The drug loaded batches were evaluated for percentage yield, drug entrapment efficiency, in vitro release, and release kinetics. Particle size distribution of beads was measured by SEM. No significant drug-polymer interactions were observed in FT-IR studies. In-vitro drug release profile of Tacrolimus micro beads in phosphate buffer pH 6.8 exhibited zero order release with kinetics of super case II-transport.The sustained release effect of microbeads depends on the polymer concentration and type of polymer used in the formulation. Hence the formulated Microbeads of sodium alginate with xanthan gum as release modifiers could be used as an alternative and cost effective carrier.