Tween 60

Octocrylene was purchased from Sigma-Aldrich, and ethanol absolute for analysis was obtained from Merck. Tween^® 60, Lanette^® O, Cetiol^® CC, Captex^® 335 and Cosmedia^® Guar were purchased from BASF. Tegosoft^® TN was obtained from Evonik Industries, whereas paraffinum liquidum and glycerol were provided by Chempur (Piekary Śląskie, Poland). The concentrated PRISMA HTTM solution, hydration solution, and skin-PAMPA plates were obtained from Pion Inc. (Billerica, MA, USA). Cell culture media (high-glucose DMEM, melanocyte growth medium, fetal bovine serum, trypsin–EDTA solution, and penicillin–streptomycin solution), Triton X100, and DMSO were purchased from Sigma-Aldrich (Seelze, Germany). Human epidermal melanocytes (HEM) and dermal fibroblasts (HDF) were purchased from Sigma-Aldrich, while HaCaT human skin keratinocytes were kindly provided by Prof. Marta Michalik from the Department of Cell Biology, Jagiellonian University in Kraków, Poland. Both (+)- and (−)-usnic acid were isolated, from Cladonia arbuscula and C. uncialis, respectively, as described previously [4 (link)]. Lactate dehydrogenase (LDH) assay kits were obtained from Clontech (Mountain View, CA, USA).

Disulfiram (CAS number 97-77-8), Kolliphor RH40, Myrj 52, oleic acid, Tween 20, and Tween 80 were purchased from Sigma-Aldrich (Saint Louis, WI, USA). Apifil, Capryol 90, Capryol PGMC, cetylpalmitate, Compritol 888 ATO, Labrafac Lipophile WL 1349, Labrafac PG, Lauroglicol 90, Geleol FPF, Geleol mono/dyglicerides NF, Geloil SC, Labrafil M 2125 CS, Labrafil 1944 CS, Labrasol, Labrasol ALF, Monosteol, Precirol Ato 5, Softisan 601, Suppocire CM, Suppocire DM, Suppocire NB, Suppocire CS2X, and Transcutol HP were kindly gifted by Gatefossé (Lyon, France). Capmul MCM and Mygliol 812 N were provided by Abitec (Columbus, OH, USA). Dynasan 116, Dynasan 118, Inwitor 900 F, Witepsol E76, and Witepsol E85 were donated by IOI Oleochemical (Hamburg, Germany). Lipoid S75 was gifted by Lipoid GmbH (Ludwigshafen, Germany). Kolliwax CA, Kolliwax CSA, Kolliwax GMS II, Kolliwax S, Kolliphor P188, Kolliphor ELP, Kolliphor HS15, and Tween 60 were provided by BASF (Ludwigshafen, Germany). Squalene and Squalane were acquired from EFP Biotek (Figueira da Foz, Portugal). Tween 40, Span 20, Span 40, Span 60, and Span 80 were gifted by SEPPIC SA (Paris, France). Water (Ω = 18.2 MΩ.cm, TOC < 1.5 µg/L) was ultrapurified (Sartorius^®, Gottingen, Germany) and filtered through a 0.22 µm nylon filter prior to use. All the other reagents were analytical or High Performance Liquid Chromatography (HPLC) grade.