Glycerol accelerates recovery of barrier function in vivo

Two studies were performed to evaluate the influence of glycerolon the recovery of damaged stratum corneum barrier function.Measurements of transepidermal water loss and capacitancewere conducted in a 3-day follow-up after tape stripping (study1) and a 7-day follow-up after a barrier damage due to arepeated washing with sodium lauryl sulphate. In study 1 afaster barrier repair (transepidermal water loss) was monitoredin glycerol-treated sites. Significant differences between glycerolopen vs. untreated and glycerol occluded vs. untreated wereobserved at day 3. Stratum corneum hydration showedsignificantly higher values in the sites treated with glycer-olzocclusion, compared with all other sites. In study 2 a fasterbarrier repair was seen in glycerol-treated sites, with significantdifferences against untreated and base-treated sites 7 days afterthe end of the treatment. Stratum corneum hydration showedhighest values in the glycerol treated sites after 3 days oftreatment. Glycerol creates a stimulus for barrier repair andimproves the stratum corneum hydration; stratum corneumhydration is not strictly related to barrier homeostasis and canbe optimized by different mechanisms and pathways. Theobserved effects were based on the modulation of barrier repairand were not biased by the humectant effect of glycerol. As theglycerol-induced recovery of barrier function and stratumcorneum hydration were observed even 7 days after the endof treatment, glycerol can be regarded as a barrier stabilizingand moisturizing compound. Key words: tape stripping; SLSwashing; transepidermal water loss (TEWL); capacitance;occlusion; barrier repair.(Accepted May 19, 1999.)Acta Derm Venereol 1999; 79: 418–421.Joachim Fluhr, Department of Dermatology, KarlsruheHospital, Sta¨dt. Klinikum, Moltkestrasse 120, D-76133Karlsruhe, Germany.The mechanisms promoting barrier repair in vivo afterstripping of the stratum corneum (SC) and repeated irritationwith sodium lauryl sulphate (SLS) are not completely clear:the modulation of water flux is probably a key factor involvedin barrier repair (1–7). It is known, that glycerol represents ahygroscopic compound capable of absorbing water from theenvironment and deeper parts of the SC.The purpose of the present study was to evaluate in vivothe effects of glycerol and occlusion in the promotion ofbarrier repair. Two studies were performed to evaluate theeffect of a repeated application of glycerol on damaged SCbarrier. The barrier disruption was performed by tapestripping (study 1) and by repeated washing with SLS over4 days (study 2).MATERIALS AND METHODS