目的 以泊洛沙姆188（P188）为稳定剂制备高载药量的雷公藤红素纳米混悬剂（Cel-NSps），提高药物的溶解度、释放度和抗肿瘤药效。方法 采用微型化介质研磨法和沉淀法制备Cel-NSps，通过动态光散射法、透射电子显微镜和X射线衍射（XRD）法对粒径、形貌和晶型进行表征并考察其稳定性，透析袋法考察体外释放情况；MTT法评价其对小鼠乳腺癌细胞4T1、人肝癌细胞HepG2、人皮肤恶性黑色素瘤细胞SK-MEL-28、人乳腺癌细胞MCF-7的细胞毒性。结果 微型介质研磨法制备的Cel-NSps平均粒径为（215.7±0.7）nm，多分散指数（PDI）为0.17±0.02，Zeta电位为（-18.0±0.6）mV，平均载药量为（87.62±1.02）%，形状不规则，药物在纳米混悬剂中以晶形态存在；在磷酸盐缓冲液（PBS）、0.9% NaCl、5%葡萄糖、血浆和人工肠液中能稳定存在，但在人工胃液中不稳定；沉淀法制备的Cel-NSps平均粒径为（133.1±0.8）nm，PDI为0.13±0.02，Zeta电位为（-16.9±1.2）mV，平均载药量为（86.39±0.21）%，近乎球形，药物在纳米混悬剂中以无定形态存在，在各种生理介质中都能稳定存在，可用于口服或静脉注射给药。微型化介质研磨法制备的Cel-NSps呈匀速缓慢的释放，144 h累积释放54.40%；沉淀法制备的纳米混悬剂呈两相释放，前48 h快速均匀释放，之后非常缓慢释放，144 h累积释放73.12%，而原料药144 h仅释放11.09%。MTT实验表明，Cel-NSps对4T1、HepG2、SK-MEL-28、MCF-7细胞具有显著的生长抑制作用且呈剂量依赖性，对4种细胞的IC₅₀在0.92～1.96 μg/mL。结论 以P188为稳定剂用2种不同方法制备了小粒径、高载药量的Cel-NSps，成功解决了溶解度差和释放度低的难题，且制备方法简单，易于工业化生产，为雷公藤红素的新药研发奠定了基础。

Objective To prepare celastrol nanosuspensions (Cel-NSps) using poloxamer 188 as stabilizer in order to improve the solubility, drug release, and anti-tumor activity of celastrol. Methods The Cel-NSps were prepared by miniaturized media milling method and anti-solvent precipitation method. The particle size, morphology, and drug crystalline of the resultant nanosuspensions were examined via dynamic light scattering, transmission electron microscopy and X-ray powder diffraction assay. We also evaluated their particle size change in different physiological media and in vitro release profile via dialysis bag method. MTT assay was used to evaluate their in vitro cytotoxicities against 4T1, HepG2, SK-MEL-28 and MCF-7 cells. Results The average particle size of Cel-NSps prepared by the miniaturized media milling method was (215.7±0.7) nm, with the PDI of 0.17±0.02, Zeta potential of (-18.0±0.6) mV, and the average drug loading of (87.62±1.02)%. The resultant nanosuspensions were irregular in shape and the drug existed in a crystal state. They were quite stable in PBS, normal saline, 5% glucose, plasma, and artificial intestinal juice, but unstable in artificial gastric juice. For the Cel-NSps prepared via precipitation method, the average particle size of (133.1±0.8) nm, PDI of 0.13±0.02, Zeta potential of (-16.9±1.2) mV, and the drug loading of (86.39±0.21)%, their shape was almost spherical. In this case, Cel was in an amorphous form and Cel-NSps were stable in various physiological media, which could be used for oral or intravenous administration. As to the in vitro release experiments, the nanosuspension prepared by the miniaturized media milling method showed a uniform and slow release, with a cumulative release rate of 54.40% within 144 h, while the nanosuspension prepared by precipitation method showed a two-phase release, a rapid release in the first 48 h followed by a very slow release with a cumulative release of 73.12% within 144 h, in contrast of only 11.09% within 144 h for free Cel. MTT assay showed that Cel-NSps had a significant cytotoxicities against 4T1, HepG2, SK-MEL-28 and MCF-7 cells in a dose-dependent manner, with the IC₅₀ of 0.92-1.96 μg/mL. Conclusion Cel-NSps were successfully prepared via two different method using P188 as a stabilizer with small particle size and high drug loading. Nanosuspension helped to solve the problem of poor solubility and low release of free Cel with the preparation method being simple and easy to scale up for industrial production. The research result of this paper provided a foundation for the development of new drugs on the basis of Cel.

R286.2

国家自然科学基金委-广东省联合基金项目（U1401223）；中国医学科学院医学创新基金资助项目（2016-I2M-1-012）