Optimization and characterization of xanthan gum based multiparticulate formulation for colon targeting

To optimize and characterize xanthan gum multi-particulate formulation for colon targeting, which increases the residence time at the absorbing surface of the colon. Xanthan gum was dispersed in cold water containing drug and was permitted to expand for 2 ​h. Sodium alginate was blended well in 10 ​ml of water. Xanthan gum solution containing the drug was added to sodium alginate solution and 0.3 ​ml of glutaraldehyde was added to the dispersion, with constant stirring. Then, polymer-drug solution was added dropwise into 5% w/v calcium chloride solution with continuous stirring, producing microspheres filtered by Whatman filter paper and dried at 30 ​°C–40 ​°C. Microspheres were performed by chemical cross-linking with glutaraldehyde, which increased the maximum drug entrapment efficiency up to 73.63 ​± ​0.65% with an increasing concentration of xanthan gum polymer 0.7% w/v for the optimized F6 batch. Better results were found by increasing the polymer concentration along with the glutaraldehyde concentration. The kinetics of drug release for the F6 batch was considered as an optimized batch because the regression value was found to be 0.997 in the peppas model. The accelerated stability study on the optimized F6 batch performed to learn whether the drug has any change during its period of usability. The polysaccharide remains intact in the stomach and intestine and the drug was released in the colon with low toxicity and biodegradability. The present studies showed that optimizing and characterizing xanthan gum multi-particulate formulation for colon targeting gives metronidazole the most effective and controlled delivery.