In vivo hair re-growth efficacies of minoxidil preparations: distearyldimethylammonium chloride vesicles, cellulose acetate phthalate microparticles, and poloxamer solution

Cationic distearyldimethylammonium chloride (DSDMAC) vesicles, anionic cellulose acetate phthalate (CAP) microparticles, nonionic poloxamer solutions were prepared as minoxidil (MXD) vehicles. According to in vitro skin retention experiments, no significant amount of MXD was left on skin when encapsulated in CAP microparticle or dissolved in poloxamer 235 solution. On the other hand, an appreciable amount of MXD was left on skin when encapsulated in the cationic vesicles. It is believed that an electrostatic interaction of the vesicles with skin is responsible for higher skin retention. In addition, the in vitro skin permeation of MXD was much higher with the vesicles. As a result, in vivo hair growth efficacy of the vesicle preparation was higher than those of CAP microparticle and poloxamer solution.