A novel chitosan nanocapsule for enhanced skin penetration of cyclosporin A and effective hair growth in vivo

Hair loss due to medical conditions, such as alopecia, male pattern baldness, and cancer chemotherapy treatment, has been a common problem for many individuals. Cyclosporin A (CsA), a fungal metabolite, has been reported to be a hair growth modulatory agent and is a potential drug for hair regeneration. However, the effect of topical application of CsA is limited by its poor water solubility. Several delivery systems developed to enhance its solubility still showed poor skin penetration. To overcome these limitations, in this study, we have developed a novel chitosan nanocapsule platform using Pluronic F127 and chitosan without any chemical crosslinking or complicated preparation steps for the enhanced water solubility and high transdermal penetration of CsA. The chitosan nanocapsules (ChiNCs) optimized in terms of structural stability by using chitosan with various molecular weights ranging from 3 to 100 kDa enhanced the skin permeation of CsA through human cadaver skin in vitro. Topical administration of the CsA loaded ChiNCs increased the hair follicles by c.a. 7 times higher than that of the control group, and effectively induced hair growth in C57BL/6 mice in vivo. These results suggest that ChiNCs could be used as a platform for effective transdermal delivery of various hydrophobic drugs.