JOURNAL OF COSMETIC SCIENCE 224 Dermal use of unsaponifi able compounds in the treatment of skin disorders is largely unexplored but has been recognized as promising according to two patents (75,76). De- spite the lack of direct evidence, it has been clearly emphasized that unsaponifi able com- pounds might contribute signifi cantly to an effective wound-healing action (2,27,77). It is, however, crucial to understand that in the treatment of wounds, fatty acids of triglyc- erides also play an important role (2). It is therefore reasonable to recommend the use of unrefi ned vegetable butters and oils because unsaponifi able compounds are removed dur- ing the refi ning process. Unsaponifi able compounds are also not very common in cosmetics. In contrast to a large number of vegetable butters and oils, only a few unsaponifi able compounds have been reported to be used as cosmetic ingredients in dermal formulations: unsaponifi able com- pounds from shea (Vitellaria paradoxa syn. Butyrospermum parkii) butter, canola (Brassica sp.) oil, soybean (Glycine max syn. Glycine soja) oil, sunfl ower (Helianthus annuus) oil, olive (Olea europaea) oil and hydrogenated olive oil, avocado (Persea americana syn. Persea gratis- sima) oil, sesame (Sesamum indicum) oil, and corn (Zea mays) oil (78). In the context of cosmetic use, the potential of permeation enhancement (68) and a corresponding safety profi le may have to be taken into account, as cosmetic products are typically used daily and over an extended period. However, more research is needed to draw reliable conclu- sions. Considering the current body of evidence, no critical concerns should be high- lighted, and unsaponifi able compounds have been assessed to be safe in typical concentrations and practices of use in cosmetics (78). CONCLUSION Studies prove that unsaponifi able compounds express benefi cial cosmetic and therapeutic effects after dermal application. It is therefore reasonable to recommend the use of unre- fi ned vegetable butters and oils, as well as unsaponifi able compounds alone, for the treat- ment and care of skin disorders. However, research in the area of dermal application of unsaponifi able compounds is very rare, and a call for in-depth studies seems to be of great interest. REFERENCES (1) D. Janeš and N. Kočevar Glavač, Eds., Modern Cosmetics, Ingredients of Natural Origin, a Scientifi c View, Vol. 1 (Širimo dobro besedo, Velenje, Slovenia., 2018). (2) N. Poljšak, S. Kreft, and N. Kočevar Glavač, Vegetable butters and oils in skin wound healing: scien- tifi c evidence for new opportunities in dermatology, Phyther. Res., 34, 254–269 (2019). (3) D. Fontanel, Unsaponifi able Matter in Plant Seed Oils (Springer Berlin Heidelberg, Berlin, Heidelberg, 2013). (4) “A n imal and Vegetable Fats and Oils — Determination of Unsaponifi able Matter — Method Using Hexane Extraction,” ISO/TC 34/SC 11 18609 (2000). (5) F. D. Gunstone, J. L. Harwood, and F. B. Padley, The Lipid Handbook, 2nd Ed., (Chapman & Hall, London, 1994). (6) J. Bruneton, Pharmacognosy, Phytochemistry, Medicinal Plants (Editions TEC & DOC, Paris, France 1999). (7) A. Cert, W. Moreda, and M. Pérez-Camino, Chromatographic analysis of minor constituents in vegeta- ble oils, J. Chromatogr. A., 881(1–2), 131–148 (2000). (8) P. Q . Tranchida, S. Salivo, F. A. Franchina, I. Bonaccorsi, P. Dugo, and L. Mondello, Qualitative and quantitative analysis of the unsaponifi able fraction of vegetable oils by using comprehensive 2D GC with dual MS/FID detection, Anal. Bioanal. Chem., 405(13), 4655–4663 (2013).

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