The present study evaluated the effects of fatty acids commonly present in cosmetic and topical formulations on permeation enhancement across human epidermal membrane HEM lipoidal pathway when the fatty acids saturated the SC lipid domain without cosolvents Emax. HEM was treated with neat fatty acids or fatty acid suspensions to determine Emax. A volatile solvent system was used to deposit fatty acids on HEM surface to compare fatty acid enhancer efficiency in topical volatile formulations with Emax. Emax of fatty acids was shown to increase with their octanol solubilities and decrease with their lipophilicities, similar to our previous findings with other enhancers.
Chemical penetration enhancers are widely used in transdermal pharmaceuticals as well as cosmetic products. Selection of suitable enhancers in topical formulations requires an understanding of the mechanism of action of these enhancers. The objective of the present study was to evaluate the enhancement effects of a number of commonly known enhancers and cosmetic ingredients on permeation across human epidermal membrane HEM. The potencies of these chemical enhancers—maximum enhancement, E max —were compared at their highest thermodynamic activity in equilibrium with HEM i.
In physics and engineering , permeation also called imbuing is the penetration of a permeate such as a liquid , gas , or vapor through a solid. It is directly related to the concentration gradient of the permeate, a material's intrinsic permeability , and the materials' mass diffusivity. Permeation is modeled by equations such as Fick's laws of diffusion , and can be measured using tools such as a minipermeameter. The process of permeation involves the diffusion of molecules, called the permeant, through a membrane or interface.
Safety managers are well-advised to evaluate how chemical protective garments react in these tests. The selection of any protective garment is complicated and carries the potential for serious consequences should the decision prove to be incorrect or the selection in any way inadequate. For this reason, standards bodies, vendors, customers, and workers are engaged -- often in the pages of this very magazine -- in ongoing conversations to determine the appropriate levels of protection for a given task.