Butanol, permeability coefficients

Butanol, permeability coefficients in hairless mouse skin, 246,247/... 

Permeability Studies. The permeability coefficients for the four solutes plotted as a function of temperature are shown in Figure 1. Hydrocortisone experiences an increase in permeability coefficients of 10 between 10 and 70°C, while butanol and octanol experience increases in permeability coefficients of 102 over the same temperature range. The permeability coefficient of ARA-A increases by a factor of 10 between 40 and 70°C. 

Figure 1. Permeability coefficients in full-thickness hairless mouse for hydrocortisone, butanol, octanol and ARA-A as a function of temperature.

Behl et al. studied the effect of prolonged contact of hairless mouse skin with water on permeability coefficients. The authors showed that permeability coefficients increase after extended periods of hydration. Because other permeability coefficients in the database we have assembled were measured on previously unhydrated skins or skins that were hydrated for short periods, the permeability coefficients with the shortest hydration time (0.3 to 0.8 h) from Table 1 were selected for the validated database. Permeability coefficients were determined with either water or ethanol as a copenetrant. The concentrations were dilute (alcohol concentrations less than 10 M) and probably were not damaging. Six reported measurements were averaged for methanol, two for ethanol, and two for butanol, and permeability coefficients were reported singly for hexanol, heptanol, and octanol. Although this article did not specify the diffusion cell temperature, subsequent articles by the same authors describing similar data indicated that the temperature was 37°C (e.g., Behl and Barrett, 1981 Behl, El-Sayed, et al., 1983 Behl, Linn, et al., 1983). It seems hkely that the temperature was also 37°C in the experiments described in this article. 

Figure 2 ( ) Isopropyl myristate/buffer partition coefficient and (O) permeability coefficient Kof propranolol over a hydrophilic membrane from Tween 60-isopropyl myristate-butanol-water microemulsions with varying octanoic acid/propranolol ratios. (Data from Ref. 18.)...

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