Evaluation of the Hairless Rat as a Model for In Vivo Percutaneous Absorption

The study evaluated the hairless rat as a model for in vivo percutaneous absorption by comparing it to the hairy rat. It was found that hairless rat skin was a "leakier" barrier for polar compounds like mannitol, leading to higher absorption rates than in hairy rats. Progesterone absorption was also significantly higher in hairless rats. The study suggested that the structural differences in hairless rats, such as patulous cysts and enlarged sebaceous glands, might enhance absorption pathways. These findings highlighted the importance of follicular structures in passive percutaneous absorption and demonstrated significant differences in absorption based on the animal model used.