DESIGN AND OPTIMIZATION OF ZIDOVUDINE LOADED URIDDALL MUCILAGE MICROSPHERES, USING BOX BEHNKEN METHOD

Objective: The objective of the current investigation is to study the combined influence of sodium alginate, uriddall mucilage and calcium chloride on drug encapsulation efficiency and particle size of microspheres. Zidovudine-loaded sodium alginate based uriddall mucilage microspheres were prepared by the solvent evaporation method. Further, optimization of the formulation was done using a three-factor, three levels of Box-Behnken design (BBD). Microspheres were subjected to surface morphology and in-vitro dissolution studies. Sodium alginate alone or in combination with uriddall mucilage and calcium chloride has a substantial influence on encapsulation efficiency and particle size of microspheres. Optimized formulation was obtained using desirability approach of numerical optimization. The experimental values of drug encapsulation efficiency and particle size for the optimized formulation were found to be 83.12 +/- 1.38%, and 846.56 +/- 2.56 mu m respectively, which were in close agreement with those predicted by the mathematical models. The drug release was also found to be slow and extended for more than 12 h, and release rates were fitted to the Power law equation and Korsmeyer-Peppas model to compute the diffusion parameters. The Box-Behnken design demonstrated the role of the derived equation and contour plots in predicting the values of dependent variables for the preparation and optimization of zidovudine loaded sodium alginate based udiddall mucilage microsphere.