目的 为提高雪松醇的毛囊靶向递送效率，制备雪松醇纳米混悬剂（cedrol-nanosuspension，Ce-NS），进行处方工艺优化、理化性质表征，并评价其治疗雄激素性脱发（androgenetic alopecia，AGA）的药效。方法 采用溶剂-反溶剂沉淀法制备Ce-NS，在单因素实验的基础上，以粒径大小和多分散指数（polydispersity index，PDI）为考察指标，应用Box-Behnken设计-响应面法（Box-Behnken design-response surface methodology，BBD-RSM）对处方工艺参数进行系统优化。利用动态光散射（dynamic light scattering，DLS）对制剂的理化性质及贮藏稳定性进行表征。通过Franz扩散池评价体外透皮能力，采用扫描电子显微镜（scanning electron microscope，SEM）进行形态学研究并评估毛囊中纳米晶体的积累，建立C57BL/6小鼠AGA模型，对其背部皮肤组织进行苏木精-伊红（HE）染色、免疫组织化学染色评价其促进体内生发药效。结果 确定最优处方工艺为雪松醇的质量浓度为7.5 mg/mL，十二烷基硫酸钠（sodium dodecyl sulfate，SDS）用量为170 mg，羟丙基甲基纤维素（hydroxypropyl methylcellulose，HPMC）用量为130 mg，聚乙二醇（polyethylene glycol，PEG）400与水相的比例为1∶12；滴加速度为20 mL/min，搅拌速度为10 000 r/min，剪切时间为5 min。所得Ce-NS粒径为（434.47±9.90）nm，PDI为0.232±0.005，ζ电位为（-15.20±1.15）mV，实测值与模型预测值拟合良好。Ce-NS在室温下放置90 d，稳定性良好。体外透皮结果显示，24 h内Ce-NS的皮肤滞留量为（74.38±3.90）μg/cm²，较原料药组显著提高4.1倍，且在接收液中未检出。SEM扫描皮肤切片证实了雪松醇纳米晶体在毛囊内的积累。药效学实验表明，与模型组相比，Ce-NS能有效促进AGA模型小鼠毛发再生，并显著增加毛囊数量与毛发长度，且小鼠背部皮肤组织中的雄激素受体（androgen receptor，AR）表达水平下降，而Ki-67 抗原（Ki-67 antigen，Ki67）、β-连环蛋白（Beta-catenin‌，β-catenin）表达水平升高。结论 采用绿色工艺成功制备了Ce-NS，且理化性质稳定，并能显著提高雪松醇在皮肤中的滞留量以及成功靶向到毛囊，对AGA表现出良好的治疗潜力，其作用机制可能与降低雄激素水平和促进Wnt/β-连环蛋白信号通路（Wnt/β-catenin）传导有关。

Objective To enhance the hair follicle-targeted delivery efficiency of cedrol, a cedrol nanosuspension (Ce-NS) was prepared. The formulation and process parameters were optimized, the physicochemical properties were characterized, and its therapeutic efficacy in the treatment of androgenetic alopecia (AGA) was evaluated. Methods Ce-NS was prepared using a solvent-antisolvent precipitation method. Based on single-factor experiments, particle size and polydispersity index (PDI) were selected as evaluation parameters to optimize the formulation and process variables using the Box-Behnken design-response surface methodology (BBD-RSM). The physicochemical characteristics and storage stability of the formulation were determined by dynamic light scattering (DLS). In vitro transdermal performance was evaluated using a Franz diffusion cell system. Morphological characteristics were examined by scanning electron microscopy (SEM) to assess the accumulation of nanocrystals within hair follicles. An AGA model was established in C57BL/6 mice. Hematoxylin-eosin (HE) staining and immunohistochemical analysis of dorsal skin tissues were performed to evaluate the in vivo hair growth-promoting efficacy. Results The optimal formulation parameters were as follows: cedrol mass concentration 7.5 mg/mL, sodium dodecyl sulfate (SDS) 170 mg, hydroxypropyl methylcellulose (HPMC) 130 mg, and a polyethylene glycol (PEG) 400-to-water phase ratio of 1∶12. The process parameters included a dropping rate of 20 mL/min, stirring speed of 10 000 r/min, and shearing time of 5 min. The prepared Ce-NS exhibited a mean particle size of (434.47 ± 9.90) nm, a PDI of 0.232 ± 0.005, and a ζ potential of (&8722;15.20 ± 1.15) mV. The experimental values were in good agreement with the predicted values of the model. Ce-NS remained stable for 90 days at room temperature. In vitro transdermal studies showed that the skin retention of Ce-NS within 24 h reached (74.38 ± 3.90) μg/cm2, which was 4.1-fold higher than that of the raw drug group, while no cedrol was detected in the receptor medium. SEM observation of skin sections confirmed the accumulation of cedrol nanocrystals within hair follicles. Pharmacodynamic evaluation demonstrated that, compared with the model group, Ce-NS significantly promoted hair regeneration in AGA model mice, increased hair follicle density and hair length, decreased androgen receptor (AR) expression in dorsal skin tissue, and upregulated the expression of Ki67 and β-catenin. Conclusion Ce-NS was successfully prepared using a green preparation process and exhibited stable physicochemical properties. The formulation significantly enhanced the skin retention and follicular targeting of cedrol, demonstrating promising therapeutic potential for androgenetic alopecia. The underlying mechanism may be associated with the downregulation of androgen signaling and activation of the Wnt/β-catenin pathway.

R283.6

湖北省经济和信息化厅第五批中小微企业“科技副总”对接项目（61）