P1.10 BLOCK-COPOLYMER NANOPARTICLE FOR FOLLICULAR DELIVERY OF HAIR DRUGS

Won-seok Park, Jong-won Shim, Dae-seok Sung, Dae-kwon Kim,

Chang-hoon Lee, Yong-chul Shim

AmorePacific R&D Center, Yongin-si, Korea

The hair follicle is acknowledged to be a complex, dynamic structure which may contribute significantly to passive transport of compounds into the scalp. To elucidate the improved delivery of hair drugs such as minoxidil and cyclosporin A(CsA) with the use of nanoparticles, we developed a follicular delivery system based on the self-assembled block-copolymer(PCG-101) nanoparticle.

Self-assembled nanoparticles and phosphatidylcholine liposomes(330nm) containing minoxidil & CsA were prepared. The distribution pattern of fluorescence dye (rubrene), entrapped in block-copolymer and liposome, was observed in dorsal guinea pig skin and hamster ear using confocal microscopy. The two penetrated drugs were measured using the Franz diffusion cell with rodent skins. Also, the anagen induction & elongation activities of the two drugs, entrapped in nanoparticles, were observed using female C57bl/6 mice in the telogen phase.

We observed that insoluble rubrene fluorescence dye, entrapped in nanoparticles, penetrated via the pilosebaceous pathway in guinea pig skin and hamster ear region.   In the Franz cell experiment, minoxidil, which was entrapped in nanoparticles of the 40nm size, diffused significantly more in hairy guinea pig skin —by 1.8~2.4 fold-- compared to those in liposome and ethanol solution. There was no significant difference in the activity of anagen induction of C57BL/6 mouse between 3% minoxidil solution (propylene glycol and ethanol) and 0.5% minoxidil nanoparticle solution. Also, the same dose (0.2%) of CsA, entrapped in nanoparticles, showed higher activities of anagen elongation compared to CsA dissolved in ethanol & polyol solution.

On the basis of in vitro and in vivo experimental models, block-copolymer nanoparticles can be effectively used as a permeation shunt system via pilosebaceous units in substitution for liposomes.