Vitamins have a different functionality in cutaneous use, some are particularly interesting in the cosmetic field, others are even prohibited
Already from the term “vitamin”, which contains the word life, one can emphasize the indispensability of these valuable substances for the human body. In fact, it is absolutely not possible to do without it, if one does not want to run into serious health problems. Vitamins participate in biochemical reactions that allow the proper development of biological processes of fundamental importance, without which it would not be possible to survive. For cutaneous use, they have a different functionality from the systemic one but, despite this, some are particularly interesting in the cosmetic field, while others are even prohibited. In the first group, we find vitamins C, B3 or PP, pantothenic acid or provitamin B5, among the water-soluble ones, and certain derivatives of vitamins A and E among the fat-soluble ones. Vitamin D is prohibited for cosmetic use in Europe, pure K and A, or retinoic acid (authorized in the pharmaceutical field, but only on medical prescription, because of the many adverse effects). The presence of vitamins in cosmetic products is always appreciated by consumers because they recognize their beneficial importance for the immune system and everything related to health and defense against external agents is always well accepted; in fact, it’s part of a very popular market trend identified as healthy beauty.
Antioxidant effect of vitamin C and protection against UV rays
Pure vitamin C, in the form of ascorbic acid, is a fairly unstable white powder in aqueous solution, especially in the presence of heat and light; it quickly oxidizes to dehydroascorbic acid, loses its effectiveness and colors the initially transparent solution yellow-brown which stains the skin and tissues. As a result, in cosmetics it is quite difficult to use pure ascorbic acid, unless special formulation stratagems are studied, for example by incorporating it into the internal phase of a silicone water emulsion or into the inside liposomes, in order to protect the dissolved ascorbic acid molecules. in the internal aqueous phase from contact with the oxygen in the air. Alternatively, the ascorbic acid solution is maintained at a pH below 3.5, in combination with other antioxidants such as ferulic acid, bearing in mind, however, that with such acidity the product could be irritating. Some use a packaging with a cap fitted with a button containing the powder which, when pressed, brings the vitamin into a solution of a few ml which requires use in a short time. In cosmetics, the use of stable vitamin C derivatives is much more widespread.Among them, I recall magnesium or sodium salts, which can be recognized on the product label with the corresponding name Inci (International nomenclature cosmetic ingredients), magnesium or sodium ascorbyl phosphate, 3-o-ethyl ascorbic acid, ascorbyl glucoside and ascorbyl methylsilanol pectinate. Apart from the last one which is only partially soluble in water, the others are water-soluble and stable in aqueous solution in certain pH ranges. Among the fat-soluble derivatives of vitamin C, I recall ascorbyl palmitate and ascorbyl tetraisopalmitate. All these substances, to be functional, must release ascorbic acid on the skin, thanks to cutaneous esterases. Some derivatives are more active than others precisely because of the release rate of the active molecule. The cosmetic actions of vitamin C mainly concern the antioxidant effect on the hydrophilic part of the cell, the protection against oxidative damage from UV rays, the reduction of melanin synthesis, also linked to the illuminating effect, and the increased collagen synthesis. It is an ingredient particularly used in the prevention of photoaging and in anti-aging cosmetics. The “synergistic partner” of vitamin C is vitamin E, or alpha-tocopherol, an antioxidant of the lipophilic part of the tissues. Physically, it looks like a very thick oil with a pale yellow color. It is rather unstable in the presence of oxygen and tends to oxidize rapidly; therefore, a more stable derivative of it is used in cosmetics, tocopherol acetate, which will appear on the label as tocopherol acetate. In addition to its antioxidant action, it reduces skin dehydration, is emollient, protective and soothing for all skin that is fragile and chapped by the cold. It is also positively used on cutaneous radiodermatitis that may occur following radiotherapy treatments.
Vitamin A, never pure: the effectiveness of its derivatives
Another fat-soluble vitamin of great cosmetic interest is vitamin A. As we have said, pure vitamin A is not used in cosmetics but its safer derivatives, namely retinaldehyde (inci retinal), retinol (inci retinol) and retinol palmitate or acetate (inci retinyl palmitate or acetate). On the skin, they are transformed into retonoic acid thanks to the presence of cutaneous enzymes. The first two derivatives show greater efficiency than the latter which take much longer to convert. The cosmetic effects of vitamin A derivatives in cosmetics relate to increased skin cell proliferation, reduced photoaging damage, improved fine lines, elasticity and firmness. They are therefore widely used in anti-aging products, especially after 40 years. Lately it’s been set as the maximum usable dose of retinol at 0.3% in face products and 0.05% for body, so don’t be surprised if you find it at the bottom of the list. ingredients. This absolutely does not mean that he is not very active, on the contrary.
Vitamins B3 and B5 stimulate the synthesis of ceramides
The last two vitamins of cosmetic interest are water-soluble. Vitamin B3, or PP, or nicotinamide (inci niacinamide) is a multifunctional ingredient with extraordinary performance. Indeed, depending on the concentration, it shows a specific action. At 2%, they stimulate the synthesis of ceramides which, as the main components of the skin barrier, help retain water in the stratum corneum and therefore keep the skin more hydrated. It is therefore perfect in body and face creams for the cold season, and also recommended in cases of atopic dermatitis or xerotic skin, that is, skin so dry that it has flaking and itching, as it also helps to reduce the itching sensation. And it is also useful as an anti-aging agent, or in skin suffering from couperose or rosacea, as it is soothing and anti-redness. At 4% it is an excellent antibacterial, extraordinarily effective for impure skin with pimples or real acne. At 5%, on the other hand, it has a lightening action on hyperpigmentation. Let’s say that this ingredient cannot be missing at least in a product of our daily care. Provitamin B5, or pantothenic acid or panthenol (inci panthenol), has a transparent, semi-solid, liquid crystal-like consistency that is very beautiful to look at as well as pleasant and effective on the skin. It is particularly suitable for the skin of children and the elderly and for fragile skin, for its soothing and regenerating action: it promotes the formation of new skin tissue.
Pharmacist Editor of Pharmacist Cosmetics Blog33
Pontoeffe n. March 3, 2022 http://www.puntoeffe.it/