The Effect of a Ceramide-Containing Product on Stratum Corneum Lipid Levels in Dry Legs.

Roughly equimolar concentrations of ceramides, cholesterol, and free fatty acids arranged in lamellar sheets form the intercellular lipid barrier in the stratum corneum (SC). Intercellular lipid deficiencies, specifically ceramides, and barrier disruption are associated with many dermatologic conditions, including dry skin. This study explored the relationship between the improvement in the signs of dry skin and the amounts of ceramides in the SC by combining clinical observations with a biochemical analysis to quantify the level of SC intercellular lipids.

The influence of cellulosic coacervate composition on the flux of an entrained agent through a coacervate/sebum barrier.

Complex coacervation is the primary mechanism used in rinse-off formulations to deliver topical agents to the skin and hair; this process produces polycation-surfactant anion coacervates that entrain the agent and enhance its substantivity at these sites. This study investigates the relationship between the transport of agents released from a coacervate vehicle into artificial sebum and the coacervate's composition and properties. The flux of a model compound, kinetin, through a variety of cellulosic coacervate/sebum composite barriers prepared on cell culture inserts was determined.

Evaluating the Transport Kinetics of a Model Compound Released From Cellulosic Coacervate Compositions Into Artificial Sebum.

Complex coacervates of cationic polymers and anionic surfactants, which are produced spontaneously during the use of rinse-off formulations, represent an important delivery vehicle for topical agents to the skin surface and appendages. In this study, an artificial sebum-loaded cell culture insert method for determining the sebum diffusion properties of topical agents was optimized for in vitro release testing. This method was subsequently used to evaluate the transport kinetics of a model compound, kinetin, released from semi-solid coacervate formulations into sebum.