Preparation and Optimization of Formulation of PLGA Microspheres Containing Chinese Herbal Extract Cucurbitacin B / 中国药房

ABSTRACT

OBJECTIVE: To prepare Polylactic-co-glycolic acid)(PLGA) microspheres loaded with Chinese herbal extract cucurbitacin B.METHODS: Cucurbitacin B loaded by PLGA microspheres were prepared by modified emulsification-solvent evaporation method.Central composite design-response surface method was applied to optimize the formulation with PVA concentration and ratio of drug to polymer as independent variables,and with yield of microspheres(Y1),drug loading amount(Y2),encapsulation efficiency(Y3),mean particle diameter(Y4),and the cumulative percentage of the drug release in 24 hr(Y5) as indexes to conduct multiple linear regression and second-order polynomial equation fitting.In vitro release test was performed by modified immediate release method.RESULTS: The results showed that all response variables were greatly fitted by a second-order polynomial equation.The optimal formulation was proved to be as follows PVA concentration was 0.014 and ratio of drug to polymer was 0.066 5.The microspheres prepared in the optimal formulation were spherical and had smooth surface.Y1,Y2,Y3,Y4,and Y5 were 79.9%,7.83%,80.5%,56.18 ?m and 6.98%,respectively.The cumulative release from microspheres within 35 days reached 86.73%.CONCLUSION: Cucurbitacin B-PLGA microspheres are characterized by prolonged action and sustained-release.Furthermore,the established model has satisfactory predictability.