Cedrol-loaded dissolvable microneedles based on flexible backing for promoting hair growth.

OBJECTIVES: The dissolvable microneedles loaded with cedrol based on flexible backing were developed to deliver cedrol directly and continuously to the dermis, where the drug concentration in the hair follicle can be increased locally. METHODS: The tip-layer matrix solution was prepared by mixing cedrol and polyvinylpyrrolidone K25 (PVP K25), and the pedestal matrix solution was prepared with aqueous hyaluronic acid. The cedrol-loaded dissolvable microneedles (cedrol-DMNs) were prepared under vacuum conditions. The mechanical properties, pig skin penetration efficiency, in vitro cutaneous permeation test, and the amount of drug in the skin and receptor chamber were evaluated. Pharmacodynamical studies were performed with C57BL/6 mice. RESULTS: The mechanical properties of cedrol-DMNs were good. In vitro cutaneous permeation tests and pharmacodynamical studies demonstrated that cedrol-DMN could efficiently deliver the drug to the deep dermis and effectively promote hair growth. CONCLUSIONS: The cedrol-DMNs offer a promising strategy for treating patients suffering from hair loss.