Abstract:
Interactions of vesicles based on phospholipids and nonionic surfactants with hairless mouse skin were evaluated by measuring permeation of tritiated water through pretreated skin under standardized conditions. Skin was exposed to the vesicles, buffers (negative controls), and sodium lauryl sulfate solution (positive control) under both open (unoccluded) and closed (occluded) conditions. There was no difference in the water permeation rare (WPR) between a freshly prepared skin membrane and the one exposed to a pH 5 buffer. WPR was increased by reducing the pH to 2; treatment with the liposome preparation at this pH value caused a significant further increase in WPR. Effects of the nonionic surfactant vesicles were of much smaller magnitude at pH 2. Both phospholipid and nonionic surfactant vesicles had a minor effect on WPR under open conditions at pH 5.