SURFACTANT PENETRATION 107 (12) J . Escalas-Taberner, E. González-Guerra, and A. Guerra-Tapia, Sensitive skin: a complex syndrome, Actas Dermosifi liogr, 102(8), 563–571 (2011). (13) G . Honari and H. Maibach, “Skin structure and function,” in Applied Dermatotoxicology., 1st Ed., Elsevier Inc., (2014), pp. 1–10. (14) J. G. Marks, Jr. and J. J. Miller, “Structure and function of the skin,” in Lookingbill and Marks’ Principles of Dermatology, 6th Ed. Elsevier Inc., (2019), pp. 2–10. (15) S. Nafi si and H. I. Maibach, “Skin penetration of nanoparticles,” in Emerging Nanotechnologies in Immunol- ogy., 1st Ed., Elsevier Inc., (2018), pp. 47–88. (16) K. Van der Maaden, W. Jiskoot, and J. Bouwstra, Microneedle technologies for (trans) dermal drug and vaccine delivery, J. Contr. Release, 161, 645–655 (2012). (17) A. M. Hargis and S. Myers, “The integument,” in Pathologic Basis of Veterinary Disease, 6th Ed. Elsevier Inc., (2017), pp. 1009–1146. (18) H . SchlÜter, E. Upjohn, G. Varigos, and P. Kaur, Burns and skin ulcers,” in Essentials of Stem Cell Biol- ogy, 3rd Ed. Elsevier Inc., (2014), 501–513. (19) J. - H. Lee, “Keratinocyte differentiation and epigenetics,” in Epigenetics and Dermatology., 1st Ed., Elsevier Inc., (2015), pp. 37–52. (20) S. Chermprapai, F. Broere, G. Gooris, Y. M. Schlotter, V. P. M. G. Rutten, and J. A. Bouwstra, Altered lipid properties of the stratum corneum in canine atopic dermatitis, Biochim. Biophys. Acta Biomembr., 1860, 526–533 (2018). (21) N. Dayan, “Delivery system design in topically applied formulations: an overview,” in Delivery System Handbook for Personal Care and Cosmetic Products. (2015), pp. 101–118. (22) K. P. Ananthapadmanabhan, S. Mukherjee, and P. Chandar, Stratum corneum fatty acids: their critical role in preserving barrier integrity during cleansing, Int. J. Cosmet. Sci., 35, 337–345 (2013). (23) P. W. Wertz and B. van den Bergh, The physical, chemical, and functional properties of lipids in the skin and other biological barriers, Chem. Phys. Lipids, 91, 85–96 (1998). (24) N. Nakagawa, S. Sakai, M. Matsumoto, K. Yamada, M. Nagano, T. Yuki, Y. Sumida, and H. Uchiwa, Relationship between NMF (lactate and potassium) content and the physical properties of the stratum corneum in healthy subjects, Soc. Invest. Dermatol., 122, 755–763 (2004). (25) S. BiÖrklund, J. Engblom, K. Thuresson, and E. Sparr, Glycerol and urea can be used to increase skin permeability in reduced hydration conditions, Eur. J. Pharm. Sci., 50, 638–645 (2013). ( 26) A. Watabe, T. Sugawara, K. Kikuchi, K. Yamasaki, S. Sakai, and S. Aiba, Sweat constitutes several natural moisturizing factors, lactate, urea, sodium, and potassium, J. Dermatol. Sci., 72, 177–182 (2013). ( 27) J. A. Bouwstra, G. S. Gooris, J. A. van der Spek, W. Bras, Structural investigations of human stratum corneum by small-angle X-ray scattering, Soc. Invest. Dermatol., 97, 1005–1012 (1991). ( 28) B. Forslind, A domain mosaic model of the skin barrier, Acta Derm. Venereol., 74, 16 (1994). ( 29) R. M. Wang, S. R. Zheng, and Y. P. Zheng, “Reinforced materials,” in Polymer Matrix Composites and Technology. (2011), pp. 527–528. ( 30) K. R. Feingold, M. Schmuth, and P. M. Elias, The regulation of permeability barrier homeostasis, J. Invest. Dermatol., 127, 1574–1576 (2007). ( 31) Y. Kitajima, Implications of normal and disordered remodeling dynamics of corneodesmosomes in stra- tum corneum, Dermatol. Sin., 33, 58–63 (2015) ( 32) M. Gelker, C. C. Müller-Goymann, W. ViÖl, Permeabilization of human stratum corneum and full- thickness skin samples by a direct dielectric barrier discharge, Clin. Plasma Med., 9, 34–40 (2018). (3 3) K. P. Ananthapadmanabhan, D. J. Moore, K. Subramanyan, M. Misra, and F. Meyer, Cleansing without compromise: the impact of cleansers on the skin barrier and the technology of mild cleansing, Dermatol. Ther., 17, 16–25 (2004). (3 4 ) E. Lémery, S. Briancon, Y. Chevalier, C. Bordes, T. Oddos, A. Gohier, and M.-A. Bolzinger, Skin toxic- ity of surfactants: structure/toxicity relationships, Colloid. Surf. A, 469, 166–179 (2015). (35) E. Lémery, S. Briancon, Y. Chevalier, O. Thierry, A. Cohier, O. Boyron, and M.-A. Bolzinger, Surfactants have multi-fold effects on skin barrier function, Eur. J. Dermatol., 25(5), 424–435 (2015). (36) J. Caussin, G. S. Gooris, M. Janssens, and J. A. Bouwstra, Lipid organization in human and porcine stratum corneum differs widely, while lipid mixtures with porcine ceramides model human stratum corneum lipid organization very closely, Biochim. Biophys. Acta, 1778, 1472–1482 (2008). (37) P. Somasundaran, Encyclopedia of Surface and Colloid Science, 2nd Ed., Taylor & Francis Inc. (2006) (38) A. Pappas, Epidermal surface lipids, Dermatoendocrinol., 1, 72–76 (2009). (39) K. R. Smith and D.M. Thiboutot, Thematic review series: skin lipids. Sebaceous gland lipids: friend or foe, J. Lipid Res., 49, 271–281 (2008).

JOURNAL OF COSMETIC SCIENCE 108 (40) S. Motta, S. Monti, S. Sesana, L. Mellesi, R. Ghidoni, and R. Caputo, Abnormality of water barrier func- tion in psoriasis, Arch. Dermatol., 130(4), 452–456 (1994). (41) C. Cole, K. Kroboth, N. J. Schurch, A. Sandilands, A. Sherstnev, G. M. O’Regan, R. M. Watson, W. H. Irwin McLean, G. J. Barton, A. D. Irvine, and S. J. Brown, Filaggrin-stratifi ed transcriptomic analysis of pediatric skin identifi es mechanistic pathways in patients with atopic dermatitis, J. Allergy Clin. Im- munol., 134(1), 82–91 (2014). (42) C. Liu, M. Ma, G. Jin, F. Geng, Q. Wang, and S. Sun, Research process on squalene and bioactivities, J. Chin. Inst. Food Sci. Technol., 15(2), 147–156 (2015). (43) X. J. Jin, S. Chen, Z. Chen, E. Kim, J. Chung, and X. M. Yang, Effect of triglycerides metabolism on HaCaT cells after ultraviolet radiation and its possible mechanism, Process Mod. Biomed., 14(33), 6454– 6459 (2014). (44) E. Barany, M. Lindberg, and M. Loden, Unexpected skin barrier infl uence from non-ionic emulsifi ers, Int. J. Pharm., 195, 189–195 (2000). (45) A. Blanco and G. Blanco, “Proteins,” in Medical Biochemistry., 1st Ed., Elsevier Inc., (2017), pp. 21–71. (46) V. Pollock, “Proteins,” in Reference Module in Biomedical Sciences., 1st Ed., Elsevier Inc., (2007), pp. 1–11. (47) M. H. Köhler, R. C. Barbosa, L. B. da Silva, and M. C. Barbosa, Role of the hydrophobic and hydro- philic sites in the dynamic crossover of the protein-hydration water, Physica A, 468, 733–739 (2017). (48) P . N. Moore, S. Puvvada, D. Blankschtein, Role of the surfactant polar head structure in protein-surfac- tant complexation: zein protein solubilization by SDS and by SDS/C12En surfactant solutions, Lang- muir, 19, 1009–1016 (2003). (49) E . Gotte, Skin tolerance of surfactants as measured by the ability to dissolve zein. IVth International Congress on Surface Active Substances, (1964). (50 ) P . N. Moore, S. Puvvada, and D. Blankschtein, Challenging the surfactant monomer skin penetration model: penetration of sod ium dodecyl sulfate m icelies into the epid ermis, J. Cosmet. Sci., 54, 29–46 (2003). (51) S . Ghosh and D. Blankschtein Why is sodium cocoyl isethionate (SCI) mild to the skin barrier? — An in vitro investigation based on the relative sizes of the SCl micelies and the skin aqueous pores, J. Cosmet. Sci., 58, 229–244 (2007). (52) G . Imokawa, “Surfactant mildness,” in Surfactants in Cosmetics, Marcel Dekker, New York, (1997) 427-471. (53) J . A. Faucher and E. D. Goddard, Interaction of keratinous substrates with sodium lauryl sulfate. II. Permeation through stratum corneum, J. Soc.. Cosmet. Chem., 29, 339–352 (1978). (54) L . D. Rhein, “In vitro interactions: biochemical and biophysical effects of surfactants on skin,” in Sur- factants in Cosmetics., Marcel Dekker, New York, (1997), pp. 397–426. (55) K . P. Wilhelm, G. Frietag, and H. H. Wolff, Surfactant induced skin irritation and skin repair, Am. Acad. Dermatol., 30, 944–949 (1994). (56) R . L. Hill and L. D. Rhein, Characterization of the sub-micellar species in mixed surfactant solutions I: mixtures of sodium lauryl sulfate and an alkyl polyethoxy sulfate, J. Dispers. Sci. Technol. 9, 269–308 (1988). (57) M . A. James-Smith, B. Hellner, N. Annunziato, and S. Mitragotri, Effect of surfactant mixtures on skin structure and barrier properties, Ann. Biomed. Eng., 39, 1215–1223 (2010). (58) M onica A. James-Smith, D. S., and D. O. Shah, Importance of micellar lifetime and sub-micellar ag- gregates in detergency processes, Tenside Surfactants Deterg., 44, 142–154 (2007). (59) D . N. LeBard, B. G. Levineb, R DeVane, W. Shinoda, and M. L. Klein, Premicelles and monomer ex- change in aqueous surfactant solutions above and below the critical micelle concentration, Chem. Phys. Lett., 522, 38–42 (2012). (60) S . A. V. Morris, R.T. Thompson, R. W. Glenn, K. P. Ananthapadmanabhan, and G. B. Kasting, Mech- anisms of anionic surfactant penetration into human skin: investigating monomer, micelle and sub- micellar aggregate penetration theories, Int. J. Cosmet. Sci., 41, 55–66 (2019). (61) A . Lips, K. P. Ananthapadmanabhan, and M. Vethamuthu, “Role of surfactant micelle charge in protein denaturation and surfactant induced skin irritation,” in Surfactants in Personal Care Products and Decora- tive Cosmetics., CRC Press, Boca Raton, Florida (2006), pp. 177–187. (62) P . N. Moore, A. Shiloach, S. Puvvada, and D. Blankschtein, Penetration of mixed micelles into the epidermis: effect of mixing sodium dodecyl sulfate with dodecyl hexa(ethylene oxide), J. Cosmet. Sci., 54, 143–159 (2003). (63) A . Shiloach and D. Blankschtein, Predicting micellar solution properties of binary surfactant mixtures, Langmuir, 14, 1618–1636 (1998). (64) M . D. Bart and E. Fairhurst, Hydration of the stratum corneum, Int. J. Cosmet. Sci., 8, 253–256 (1986).