Some General Influences of n-Decylmethyl Sulfoxide on the Permeation of Drugs Across Hairless Mouse Skin

The influences of n-decylmethyl sulfoxide (NDMS) on the permeation of phenyl propanolamine, propranolol, acyclovir, and hydrocortisone through hairless mouse skin were investigated. Permeation of these compounds increased systematically with increasing NDMS concentration up to a limiting value for the permeability coefficient of about 0.1 cm/h. Permeability coefficients obtained with stripped skin indicated that, where NDMS has its maximal effect, the compounds diffuse through the skin as if there were no straturn corneum. Diffusion lag times of the test compounds through skin sections exposed to NDMS were far shorter than lag times in control experiments. The kinetics of NDMS action were assessed by pretreating skin sections for various periods of time with the enhancer and then assessing permeability. When applied as a 10mM aqueous solution, the full effect of NDMS was obtained in 3h of exposure and the effect lasted for at least 24h. Treating the skin with ethanol/water (2: 1) to elute NDMS after the pretreatment did not diminish its effect. Propranolol and phenyl propanolamine solubilized NDMS, presumably through the formation of mixed micelles, which had a profound effect on the permeation rates of both drug and enhancer