Zinc alginate-carboxymethyl cashew gum microbeads for prolonged drug release: development and optimization

Isoxsuprine HCl-loaded microbeads using sodium alginate (SA)-carboxymethyl cashew gum (CMCG) polymer-blends were developed through ionotropic-gelation technique using ZnSO4 as cross-linker. Effects of polymer-blend ratio and cross-linker concentration on drug encapsulation efficiency (DEE) and cumulative drug release at 7 h (R7 h) were optimized by 3(2) factorial design. Optimized microbeads were of excellent combination of high DEE (79.92±2.51%) and suitable sustained drug release pattern over a prolonged period of 7 h (58.67±2.26%). The microbead surface morphology was analyzed by SEM. The physical state of isoxsuprine HCl within the optimized microbead matrix was analyzed by FTIR and DSC. In vitro isoxsuprine HCl release from alginate-CMCG microbeads in phosphate buffer (pH, 6.8) showed prolonged sustained drug release and Korsmeyer-Peppas model (R2=0.9959-0.9992) over 7 h.