EFFECT OF AGE ON THE IN-VITRO PERCUTANEOUS-ABSORPTION OF PHENOLS IN MICE

The effect of age on the in vitro dermal absorption of acetamidophenol , phenol, cyanophenol and heptyloxyphenol was examined. Skin from pre- clipped male C57BL/6N mice of ages 3, 15 and 27 months was mounted in flow-through diffusion cells. [C-14]Phenol and its analogues (4 mu g/c m(2)) were applied to the skin (0.32 cm(2)) in ethanol (5 mu l) and ab sorption was measured under occluded conditions for 72 hr. Significant age effects on the disposition of phenol and heptyloxyphenol were obs erved in the penetration of compound into the receptor fluid as well a s that retained in the skin. The receptor fluid content of these two c ompounds was significantly greater in 27-month-old mice compared with the younger animals. In addition, penetration of phenol in 15-month-ol d mice was significantly greater than in 3-month-old mice. However, th e differences in phenol penetration were small (< 5%). The maximal flu x of cyanophenol and phenol penetration were affected by age. The maxi mal flux for cyanophenol was significantly lower in 15-month-old mice than in 3- and 27-month-old animals. The maximal flux for phenol was s ignificantly greater in 27-month-old mice compared with the younger an imals. The overall effect of age on the in vitro dermal absorption of phenols in C57BL/6N mouse skin appears to be compound dependent.