Rheological Properties and Composition Affecting the Skin Permeation of a Model of a Hydrophilic Drug in Lecithin Reverse Wormlike Micelles

The study examined how the rheological properties and composition of lecithin reverse wormlike micelles (LRWs) affect the skin permeation of a hydrophilic drug. Using D (-)-ribose or glycerol as polar compounds, and liquid paraffin or isopropyl myristate (IPM) as oils, with 6-carboxyfluorescein (CF) as the drug model, it was found that LRWs have moderate viscosity at 25°C but lower viscosity at 32°C, aiding skin penetration. The highest skin permeability of CF occurred with IPM, indicating that both the stratum corneum and hair follicle routes are involved in drug permeation, and that IPM's interaction with sebum enhances follicular penetration.