Guar gum based microcapsules for colonic delivery of albendazole: Development and In-vitro evaluation

The present study was aimed to develop and evaluate Albendazole microcapsules using guar gum, a natural polymer for colon-specific delivery for better treatment of Helminthiasis, Filariasis, and colorectal cancer by avoiding the side effects. Microcapsules were prepared by the use of different concentrations of sodium alginate and guar gum. The polysaccharides guar gum reacted with sodium alginate in the presence of calcium chloride to form microcapsules with a polyelectrolyte complex membrane by electrostatic interactions between the two charged polymers. The microcapsules were then studied for entrapment efficiency, surface morphology and particle size analysis. In vitro drug release study in presence and absence of cecal content were also studied. Further, kinetic modellings were employed to find out release mechanisms. The entrapment efficiency was found to be in the range 20%-30%. Increase in concentration of sodium alginate and guar gum showed better platform for encapsulation because of low viscosity. Albendazole microcapsules were found almost spherical, free flowing and non-aggregated. The surfaces of microcapsules are porous and wavy. The particle size was in the range 6001000μm and the particle size range is maximum for microcapsules with high concentration of sodium alginate and guar gum. The in vitro drug release of microcapsules in GI simulated conditions were done and found that the cumulative percentage release from all the drug loaded batches of microcapsules fall within the range of 53% to 99 % in 24 hours study and it was found that the %cumulative release in microcapsules encapsulated with guar gum was maximum for Batch F (93.85%) and minimum for Batch J (61.40%) in 24 hrs.. The results of in vitro release study indicated that the amount of drug release decreased significantly with an increase in guar gum concentration but it was reverse with respect to sodium alginate concentration. Also incorporation of guar gum as coating shows maximum release in anaerobic colonic condition with cecal content as well as lower release in GI simulated condition. The rate of drug release follows Korsmeyerpeppas model that is the drug release is by diffusion and erosion.