Tranexamic acid (TA) on pigmentation: Kondou et al. have published results from a clinical study examining the effects of a tranexamic acid (TA) emulsion applied topically to melasma and freckles. The study involved 33 subjects, 25 with melasma and 8 with freckles, who applied the TA emulsion for five to eighteen weeks, after which their skin pigmentation was visually assessed by a dermatologist.
Researchers found that the TA emulsion had improved the pigmentation in 20 subjects with melasma (80%) and 6 subjects (75%) with freckles. No side effect was recognized and thus the TA emulsion was deemed safe. In regard to changes over the course of the study, marked improvement was observed within eight weeks for melasma but within 12 weeks for freckles; therefore, improvement was considered to require at least two months of topical application. The authors concluded the TA emulsion was an effective cosmeceutical that provided a whitening effect on melasma and freckles through inhibition of melanin synthesis. It also prevented the appearance of new pigment spots and freckles.
Trans-retinol and skin: Pudney et al. have published an in vivo confocal Raman study examining the delivery of trans-retinol into human skin.2 Delivery to real living systems such as skin can be difficult to execute and is problematic to confirm and measure. So far, methods for studying the delivery of compounds through the skin are mostly ex vivo; thus they inherently influence the skin and may not translate directly to an in vivo situation. Raman spectroscopy is unique in its ability to measure biological processes in vivo.