pH与微乳辅料对白藜芦醇稳定性影响的研究

本研究考察p H和微乳处方中的辅料对白藜芦醇稳定性的影响。首先制备含等量白藜芦醇、p H不同的溶液,再分别将油相、乳化剂及助溶剂与白藜芦醇单独配伍或辅料混合后配伍,制成混合溶液,在40℃下放置不同时间,定时取样测定。分别对浓度-时间曲线按各级动力学方程进行回归,由降解速率常数推断p H及各辅料对白藜芦醇稳定性的影响。结果表明,白藜芦醇溶液稳定的p H范围为3.6⁵.0;微乳各辅料单独与白藜芦醇配伍均加速了白藜芦醇的降解,但辅料混合后再与成分配伍其降解减慢,甚至可改善白藜芦醇的稳定性。制备白藜芦醇微乳适合选择聚氧乙烯蓖麻油为乳化剂,聚乙二醇400为助溶剂。 

Effect of p H and microemulsion excipients on the stability of resveratrol

In this study, the effect of p H and microemulsion excipients on the stability of resveratrol were examined.First, solutions containing equivalent resveratrol with various p H were prepared.Then resveratrol- excipient solutions were formulated, in which resveratrol was either mixed with oil phase, emulsifier, and co- solvent, separately, or blended with them together.The test solutions were placed under 40 ℃ and assayed at specific intervals.Curves of concentration versus time were fitted by sorts of dynamic equations, respectively, from which constants of degradation rate were calculated. The results showed that stable p H range of resveratrol was 3.6 to 5.0. Though microemulsion excipients accelerated degradation of resveratrol when they were mingled with the ingredient separately, the mixture could make resveratrol decomposition slower. Some excipient mixture even improved resveratrol stability.The appropriate emulsifier and co- solvent for resveratrol microemusion were cremophor EL and polyethylene glycol 400, respectively.