Harada S, Takahashi Y, Nakagawa H
Pharmaceuticals Research Center, Kanebo Ltd., Osaka, Japan.
Biol Pharm Bull. 1993 Sep;16(9):884-8. doi: 10.1248/bpb.16.884.
Transdermal administration of emedastine was tested in vitro and in vivo. In the diffusion cell method in vitro, emedastine free base was more permeable by transdermal administration than emedastine difumarate. Emedastine had higher permeability in hydrophobic vehicles than in hydrophilic vehicles, and was most permeable in fatty acid monoesters. It was suggested that the change in permeability of emedastine from these vehicles was dependent on the change in its partition from the vehicle to the skin. In studies using rabbits in vivo, emedastine had high permeability from fatty acid monoesters and fatty acid diesters as found in in vitro studies, and bioavailability of the drug after transdermal administration was greater than that after peroral administration. The flux of emedastine in vitro was correlative with the pharmacokinetic parameters in vivo. Consequently, it is clear that transdermal permeability of emedastine is very high and that the drug may be efficacious in the system after administration by these means.
对依美斯汀的经皮给药进行了体外和体内试验。在体外扩散池法中，依美斯汀游离碱经皮给药的渗透性比富马酸依美斯汀更高。依美斯汀在疏水性载体中的渗透性高于亲水性载体，在脂肪酸单酯中渗透性最高。提示依美斯汀从这些载体中的渗透性变化取决于其从载体到皮肤的分配变化。在体内使用兔子的研究中，如体外研究所示，依美斯汀从脂肪酸单酯和脂肪酸二酯中的渗透性很高，经皮给药后药物的生物利用度高于口服给药后。依美斯汀在体外的通量与体内药代动力学参数相关。因此，很明显依美斯汀的经皮渗透性非常高，并且该药物通过这些方式给药后在体内可能有效。
