利福布汀纳米结构脂质载体的制备工艺及体外评价

The preparation of rifabutin nanostructured lipid carriers and in vitro evaluation

目的:将利福布汀(rifabutin, RFB)制成利福布汀纳米结构脂质载体(RFB-NLC),提高其水溶性、缓释性。方法:首先进行RFB含量测定方法学考察,以乳化剂用量、药物与脂质用量比、固液脂质用量比为处方因素,以包封率和载药量为指标,单因素考察基础上,以Box-Behnken效应面法进行处方优化,采用差式扫描量热法对RFB-NLC晶型表征,电镜观察RFB-NLC形态。测定最优处方下RFB-NLC的体外释放度,拟合其释药动力学方程。采用CCK-8法评价RFB-NLC体外细胞毒性,采用耻垢分枝杆菌评价抗菌活性。结果:RFB-NLC的最优处方为乳化剂用量2.37%,药物与脂质比1∶20,固液脂质比3.2∶1,此时包封率为(54.92±1.12)%,载药量为(3.05±0.11)%,体外释药符合Ritger-peppas模型,将RFB制成RFB-NLC可以降低体外抗菌的MIC、MBC值及细胞毒性。结论:RFB-NLC可提高RFB的缓释性及抗菌效果并降低体外细胞毒性,为进一步临床应用提供研究基础。

OBJECTIVE To prepare rifabutin nanostructured lipid carriers RFB-NLC,so as to improve its water solubility and sustained release characteristic.METHODS First, the methodology of RFB content determination was investigated.The dosage of emulsifier, the dosage ratio of drug to lipid and the dosage ratio of solid-liquid lipid were taken as the prescription factors, the entrapment efficiency and drug loading were taken as the indexes.The prescription optimization test and verification were carried out by Box Behnken response surface method.The crystal form of RFB-NLC was characterized by differential scanning calorimetry, and the morphology of RFB-NLC was observed by electron microscope.Finally, the in vitro release of RFB-NLC prepared with the optimal formulation was measured, its release kinetic equation was fitted, and its related characteristics were characterized.In vitro cytotoxicity of RFB-NLC was evaluated by CCK-8 assay, and antimicrobial activity was evaluated by Mycobacterium smegmatismus.RESULTS The optimal prescription of RFB-NLC was the dosage of emulsifier 2.37%,the ratio of drug to lipid 1∶20,and the ratio of solid to liquid lipid 3.2∶1.At this time, the EE% was(54.92±1.12)% and the DL was(3.05±0.11)%.The drug release in vitro accorded with the Ritger peppas model, The preparation of RFB-NLC could reduce the MIC and MBC of antibacterial in vitro.CONCLUSION The preparation of RFB-NLC can improve the sustained-release and antibacterial effect of RFB,reduce the cytotoxicity in vitro,which can provide a research basis for further clinical application.