Effect of Pretreatment Time with Enhancers on Caffeine Skin Permeability in Rats

Background: Caffeine is an edible chemical compound obtained from various plants, such as tea and coffee. Caffeine is an alkaloid that is highly hydrophilic and has limited skin permeability. The lipophilic nature of the stratum corneum is a major barrier to the passage of this substance through the skin. Topical drug delivery systems can effectively transfer caffeine to the skin. Objectives: This study investigated the effect of pretreatment time with chemical enhancers on caffeine's skin permeation. Methods: The skin was subjected to additives such as sodium lauryl sulfate, sodium lauryl ethyl sulfate, tynoline, nanoxinol, and lecithin for 5, 15, and 30 minutes. Then, the parameters of caffeine permeability and structural changes in the skin due to additive adsorption were studied using Fourier Transform Infrared (FT-IR) spectrometry. Results: The enhancers increased the permeation of caffeine through the skin. There are different mechanisms for penetration enhancers, including lipid liquefaction, disruption of lipid bilayers, and irreversible denaturation of intracellular keratin. Conclusions: Sodium lauryl sulfate can affect the skin permeability of caffeine.