Ether-water partitioning and permeability through nude mouse skin in vitro. II. Hydrocortisone 21-n-alkyl esters, alkanols and hydrophilic compounds

Abstract

The permeability coefficients obtained by means of an infinite dose diffusion cell system with nude mouse skin in vitro were compared to the ether-water partition coefficients of the following compounds: glucose, urea, glycerol, thiourea, alkanols (methanol to octanol), hydrocortisone and hydrocortisone 21-n-alkyl esters (-acetate to-heptanoate). The permeability coefficients ranged from 1.0 x 10-6 cm/h (glucose) to 0.34 cm/h (hydrocortisone-21-heptanoate). The ether-water partition coefficients ranged between 9.0 X 10-6 (glucose) and 1.4 x 104 (hydrocortisone-21-heptanoate). No general pattern emerged when the permeability coefficient is taken as a function of the ether-water partition coefficient for these compounds. Therefore the skin can not be regarded as a simple lipoidal barrier.

Passive and Iontophoretic Transport through the Skin Polar Pathway

“…A later study by Ackermann et al [4] investigating skin permeation of n-alkanols and hydrocortisone esters showed that the permeability coefficients of these permeants did not correlate with their ether-water partition coefficients in a manner predicted from those of transport across a simple lipophilic barrier. This skin transport behavior was consistent with the alternative polar pathway in skin.…”

Lipid Solubility and Molecular Weight: Whose Idea Was That

“…This thinking certainly found its way into the skin permeability area, where various investigators proposed hydrocarbons [2], diethyl ether [3], isopropyl myristate [4,27] and, finally, n-octanol [5,6,7,8] as surrogates for the stratum corneum lipid barrier. The choice of solvent seemed rather arbitrary until Anderson and coworkers showed rather convincingly that n-octanol was a good model for solute partitioning into the barrier domain of the stratum corneum [6,7,9].…”

Valence Topological Charge-Transfer Indices for Dipole Moments: Percutaneous Enhancers

“…and AEV decreased by 58% from that in Equation (6). No superposition of the corresponding G k -J k or G k V -J k V pairs is observed in Equations (6-9), which diminishes the risk of co-linearity in the fits, given the close relationship between each pair G k -J k in Equation (2) [42,43].…”

“…Equation (11) is overfitted but it is given with the purpose of justifying that µ 4-alkylanilines were represented by only one point in µ space in Equations (6)(7). The best quadratic model did not improve the fit.…”

“…When adjacent to the lipoidal membrane and its luminal side, aqueous boundary layer thickness can be modified by agitation and, for in vitro experiments, the importance of suitable stirring conditions to obtain reproducible results was recognized [3]. In comparative studies, the existence of the aqueous boundary layers, although acknowledged, was sometimes virtually ignored because of its uniformity throughout a strictly designed and controlled steady-state experimentation work [4][5][6][7].…”