I have had this discussion with a few people before. I don' tlike OS. The reason is that there is only one article that says it penetrates well(This one you show is the same one and only one that Par uses for his backup of OS).. There is way to many articles like this one I have posted that say it does nothing. OS is a UV ray blocker and thats all I have found. But lets definately keep looking. The homebrew will never be "perfect" and can always be improved. Talk to ya.
2-Ethylhexyl Salicylate (aka octyl salicylate) is an FDA-approved sunscreen for UVB absorption.
Walters, K.A., K.R. Brain, D. Howes, V.J. James, A.L. Kraus, N.M. Teetsel, M. Toulon, A.C. Watkinson and S.D. Gettings. Percutaneous Penetration of Octyl Salicylate from Representative Sunscreen Formulations through Human Skin In Vitro. Fd. Chem. Toxic. 1997. 35: 1219-1225. [Reprinted with permission from Elsevier Science]
octyl salicylate - 06969-49-9
The human skin penetration of [14C]octyl salicylate from two representative sunscreen vehicles was determined in vitro. 3H-sucrose was incorporated into all formulations and provided a marker for membrane integrity. When applied as a finite dose in an oil-in-water emulsion vehicle containing 5% (w/w) octyl salicylate, the average total absorption of 14C over 48 hr was 0.65 ± 0.16% of the applied dose (representing a total amount permeated of 1.58 ± 0.36 ug/cm2). When applied as an infinite dose in the oil-in-water emulsion vehicle the average total absorption of 14C over 48 hr was 0.47 ± 0.22% of the applied dose (representing a total amount permeated of 27.54 ± 13.91 ug/cm2). When applied as a finite dose in a representative hydroalcoholic formulation containing 5% (w/w) octyl salicylate, the average total absorption of 14C over 48 hr was 0.23 ± 0.05% of the applied dose (representing a total amount permeated of 11.28 ± 2.55 ug/cm2). The penetration of [14C]salicylic acid [applied at a concentration of 2.7% (w/w), in the oil-in-water emulsion] was also determined. When applied as a finite dose the average total absorption of 14C over 48 hr was 1.14 ± 0.23% of the applied dose (representing a total amount permeated of 1.65 ± 0.39 ug/cm2). These results suggest that the in vitro human skin permeation of octyl salicylate is relatively low. The amounts of octyl salicylate and salicylic acid permeated when applied in similar vehicles were remarkably similar over 48 hr (1.58 ug/cm2 and 1.65 ug/cm2, respectively). This suggests the possibility that the 14C label appearing in the receptor fluid may, in both cases, represent salicylic acid. If this is the case, then it is possible that the amount of octyl salicylate permeating through the skin is much less than that suggested by the data obtained here. This supposition is, however, entirely speculative and has yet to be confirmed experimentally.