FORMULATION AND EVALUATION OF ENTERIC COATED MICROSPHERES OF KETOPROFEN USING NATURAL POLYMERS FOR COLON DRUG DELIVERY

摘要

Objective: The aim of the present study was to prepare and evaluate shellac -coated pectin microspheres for the colon targeted delivery of Ketoprofen. Methods: Pectin microspheres containing ketoprofen were prepared by emulsion dehydration method using different ratios of pectin (1:1 to 1:6), stirring speeds (500-1500 rpm) and emulsifier concentration (1.25% w/v). Shellac-coating of pectin microspheres was performed by emulsion–solvent evaporation technique using different core: coat ratios (1:2 to 1:5). The prepared microspheres were evaluated for surface morphology, percentage yield, particle size, percentage drug entrapment, swellability, flow properties, in vitro release studies and stability kinetics. Results: Pectin microspheres prepared by using drug: polymer ratio 1:3 and 1:4, stirring speed 1000 rpm, and 1.25% w/v concentration of emulsifying agent were selected as optimized formulations. The percentage yield was high for 1:3 and 1:4 ratio pectin microspheres. In case of shellac-coated microspheres, the percentage yield and % drug entrapment efficiency was high for ratio 1:5. Hence, the shellac-coated microspheres having core: coat ratio 1:5 was selected as an optimized formulation. Further six batches of shellac-coated pectin microspheres were prepared using optimized core: coat ratio 1:5. The release profile of ketoprofen from the six batches of shellac-coated microspheres was pH dependent. In SGF of pH 1.2, no measurable drug release observed; however, the significant drug release was observed in colonic fluid (pH 7.4). Stability studies suggested that the formulation is quite stable at 4o C and is the most suitable temperature for storage of prepared micropsheres. Conclusion: It can be concluded from the present investigation that Shellac-coated pectin microspheres are promising controlled release carriers for colon-targeted delivery of Ketoprofen