GLYCOLIC ACID & SALICYLIC ACID

They are known as fruit acids or AHAs and BHAs; they are chemical exfoliants (surface keratolytic agents) with cleansing and sebum-regulating properties. Their effectiveness is no longer in doubt, many scientific publications are available, which makes them active ingredients recognized by the medical world as effective and therefore widely used in cosmeceutical ranges. Among the most common, we will mention glycolic acid (AHA) and salicylic acid (BHA). AHAs and BHAs have several advantages:

• the results on the skin are visible quickly,
• they help and enhance the penetration of other active ingredients and therefore optimize the effectiveness of treatment treatments,
• their only drawback is that they are potentially irritating at high concentrations or for certain skin types such as sensitive, irritated, intolerant skin, etc.

In cosmetics, French and European regulations limit the concentration of glycolic acid to 10% and the concentration of salicylic acid from 0.5% to 2% in leave-on products; but the concentration is not the only element to consider, the pH (acidity) of the formula is the most important point. Glycolic acid, for example, will only be “active” in the formula if it is at a low pH (optimum at 3.4), which can make it incompatible for certain skin types. To make it less “irritating”, one solution is to buffer the solution (i.e. raise the pH close to the pH of the skin, namely 5.5), but this implies that a significant part of the glycolic acid is neutralized and therefore “inactive”. The solution? a concentration of less than 10%, a low pH and a galenic that allows safe and effective use.
In addition to their cosmetic use, they are also used, at higher concentrations, in aesthetic medicine and dermatology in various peels.

GLYCOLIC ACID

Glycolic acid is the smallest and best known of the AHAs (alpha hydroxy acids), it is a fruit acid derived mainly from sugar cane, beetroot or grapes.

It is used in cosmetics for its exfoliating properties, it is a surface keratolytic agent: by penetrating into the upper layers of the skin it reduces the cohesion forces between cells (keratinocytes) and causes an “exfoliation” of dead cells which has the consequence of accelerating what is called cell turnover.

Its exfoliating properties make it an active ingredient of choice to improve the texture and appearance of the skin. Its action is fast, the results are quickly noticeable. In repeated use it helps to treat wrinkles, fine lines, hyperpigmentation (spots), hyper seborrhea, acne …

In France, regulations limit its dosage to 10% in over-the-counter products.

Besides its use in cosmetics, it is also used in higher concentrations in medicine and aesthetic dermatology in different peels.

SALICYLIC ACID

Salicylic acid is the main and best known of the BHAs (beta hydroxy acids), it is naturally present in certain fruits (grapes, plums) and vegetables (broccoli, spinach), in plants (willow bark, meadowsweet) but it can also be of synthetic origin.

It is used in cosmetics for its exfoliating, purifying, astringent, sebum-regulating, antiseptic and soothing properties.

It is therefore a relatively versatile active ingredient, an ally of “new skin” formulas which is mainly formulated in anti-imperfection products such as products for oily skin, acne-prone skin, anti-dull complexion, anti-blemish, etc.

In France, regulations limit its dosage to between 0.5 and 2% in unrinsed and over-the-counter products.

In addition to its use in cosmetics, it is also used at high concentration in occlusive balms for local application for the treatment of warts for example, but also in aesthetic medicine and dermatology in various peels.

HYALURONIC ACID

Hyaluronic acid (HA) is a moisturizing molecule naturally present in the skin. Discovered in 1934, it has been used in humans since the 1970s, mainly in ophthalmic surgery, then in rheumatology and finally in plastic surgery. It has since become the “in vogue” active ingredient in many cosmetic products.

Hyaluronic acid is a glycosaminoglycan (GAG) from the polysaccharide family. It is a constituent element of the extracellular matrix (ECM), it not only ensures a good degree of hydration in the skin but also contributes to its tone and elasticity. Like most of the constituent elements of the skin, with age, its natural level tends to decrease both in quantity and quality.

Originally of animal origin, it is now manufactured using a bacterial fermentation process (biotechnology).

In cosmetics, hyaluronic acid is only a hydrating molecule, it is not a filler product… In the MEDICEUTICS range, we systematically use 2 “cosmetic grades”:

High molecular weight hyaluronic acid (HA), i.e. a macromolecule form almost identical to the molecule naturally present in the skin (called native form) which, by stabilizing on the skin surface, provides a film-forming effect and thus limits insensible water loss. High molecular weight hyaluronic acid (HA) is therefore an anti-dehydration active ingredient.

Low molecular weight hyaluronic acid (HA), i.e. a “fractionated” hyaluronic acid whose subunits are capable of penetrating the upper layers of the epidermis, binding to a very large number of free water molecules, thus creating a real water reservoir. Low molecular weight hyaluronic acid (HA) is therefore a moisturizing active ingredient.

These high and low molecular weight “cosmetic” hyaluronic acids are degraded in the skin by a naturally present enzyme, hyaluronidase, the degradation products then act as cellular messengers and allow the induction of neosynthesis of native hyaluronic acid by our own cells (fibroblasts), which is why hyaluronic acid is often described as an anti-aging molecule, in addition to its moisturizing properties.

In the MEDICEUTICS range, high and low molecular weight hyaluronic acids are most of the time coupled with a technical active ingredient, a combination of plant extracts and synthetic active ingredients (e.g. urea, glycerin, trehalose, sodium PCA, etc.), allowing optimum hydration in the short, medium and long term.

In aesthetic medicine and dermatology, hyaluronic acid is used as a filler or as a volumizer, it is then injected into the skin by a health professional; the hyaluronic acid used is then in the form of a more or less viscous gel (depending on the degree of crosslinking of the acid) depending on the desired aesthetic effect.