Testosterone permeation enhancers

Kaplun-Frischoff Y, Touitou E. Testosterone skin permeation enhancement by menthol through formation of eutectic with drug and interaction with skin lipids. J Pharm Sci 1997 86 1394-1399. 

These testosterone systems illustrate two different approaches to solve the problem of inadequate percutaneous absorption rate. In the former case, the patch must be applied to the body s most permeable skin site, the scrotum (which has been shown to be at least five times more permeable than ary other site). In the latter, the difficulty is resolved by creating a transdermal formulation which includes excipients to reduce barrier function. Neither solution is ideal scrotal application is clearly not preferred from a patient compliance standpoint on the other hand, permeation enhancers, by their very nature, tend to be irritating (and the more effective they are, the greater the irritation they provoke). This general problem, which presently limits the application of transdermal delivery, is now discussed in more detail. 

Meikle, A.W. Arver, S. Dobs, AS. Sanders, S.W. Rajaram, L. Mazer, N.A. Pharmacokinetics and metabolism of a permeation enhanced testosterone transdermal system in hypogonadal men influence of application site—clinical research center study. J. Clin. Endocrinol. Metab. 1996, 81, 1832-1840. 

Arver S, Dobs AS, Meikle AW, et al. Improvement of sexual function in testosterone deficient men treated for 1 year with a permeation enhanced testosterone transdermal system. J Urol 1996 155 1604-1608. 

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