OxC wrote:The effect of the enhancer is concentration-dependent and generally cosolvents containing > 60% DMSO are needed for optimum enhancement efficacy. However, at these relative high concentrations, DMSO can cause erythema and wheal of the stratum corneum. Denaturing of some skin proteins results in erythema, scaling, contact uticaria, stinging and burning sensation.
Thanks for your search. Though it doesn't convince me - beside all the invitro studies - since 70% solution transdermal never caused wrinkles, erythema, scaling, dry skin, or etc. for me.
Some are concerned about this study: https://www.ncbi.nlm.nih.gov/pubmed/24327606
Though I honestly believe such concentration are never reached in the eye, if not applied directly.