Delivering Nutrient Benefits From Cleansers To The Skin Through Enhanced Ceramide Production And Continuous Nourishment

Previous research has shown that marketed mild amino-acid surfactant based bodywashes and isethionate syndet bars containing free fatty acids can not only deposit but also deliver the fatty acids deeper into the viable epidermis, which are subsequently elongated into longer chain fatty acids. Further details on ceramide formation and metabolism dynamics are of interest to understand the fate of the delivered fatty acids. The objective of this research was to determine if the fatty acids deposited by cleansers are incorporated into skin ceramides and investigate the duration of the conversion. Healthy female subjects provided informed consent to participate in randomized, double-blind IRB-approved four-week cleansing studies. A marketed mild amino-acid based liquid cleanser was formulated with deuterated palmitic acid. Tape strip samples were collected at end of the study to measure elongated fatty acids, sphingosine and ceramide concentrations. Separately, to measure duration of conversion, living skin equivalents were independently dosed with deuterated lauric, palmitic, and stearic fatty acids for 7 days prior to harvesting for measurement of similar lipid components to measure duration of conversion. Deuterated elongated fatty acids, sphingosine, and ceramides were found in both the LSE experiment and in vivo clinical study. Additionally, the duration of conversion was measured to last at least 24 hours after final product use. Application of marketed mild amino-acid surfactant-based cleansers showed deposition and subsequent metabolism to form longer chain fatty acids, sphingosine and ceramides. This increase in natural skin nutrients is consistent with creating a stronger and better stratum corneum barrier.