Mechanistic Studies of Branched-Chain Alkanols as Skin Permeation Enhancers

Esters of 6-aminohexanoic acid as skin permeation enhancers: The effect of branching in the alkanol moiety

“…These results confirm the observation of Chantasart et al, 7 who reported that the branchedchain alkanols have a lower potency than the linear alkanols of the same molecular formula, and that the potency decreases as the hydroxy group shifts its position from the end of the enhancer alkyl chain towards its center. At their isoenhancement concentrations, the uptake amounts of the branched-chain alkanols into the intercellular lipids of hairless mouse stratum corneum were higher that those of the linear alkanols suggesting a lower intrinsic potency of the branched derivatives.…”

“…Aungst 6 reported that in C 5 -C 14 fatty acids, branched and unbranched isomers had similar effects. On the other hand, Chantasart 7 compared the effect of branched and unbranched alcohols and described a decrease in enhancement potency with a higher degree of branching.…”

Comparison of the Effects of Chemical Permeation Enhancers on the Lipoidal Pathways of Human Epidermal Membrane and Hairless Mouse Skin and The Mechanism of Enhancer Action

“…Animal skins such as from hairless mice, rabbits, shed snakes, and pigs are therefore frequently used as an alternative because they are easy to obtain, are low in cost, and have less skin-to-skin variability. [7][8][9][10] However, hairless mouse skin (HMS) lacks long-term stability in aqueous solution and is not a good model of human skin such as in the prediction of the absolute permeability coefficients for transdermal transport of polar compounds. [11][12][13] When HMS was used, proper experimental protocols such as employing short transport experiments should be utilized.…”

Passive and Iontophoretic Transport through the Skin Polar Pathway

“…H is the hindered transport factor for passive diffusion and is related to the ratio of solute molecular size to the effective pore size of the transport pathway [23]. The parallel pathway model has been used in the evaluation of chemical penetration enhancers and the examination of quantitative structure enhancement relationships of the enhancers in skin permeation studies [24,25,26,27,28,29,30,31,32]. Because the skin is a composite of two layers in series of different barrier properties (stratum corneum and underneath tissues, respectively), the total permeability coefficient of skin (P T ) can be described by [33,34]:…”