LM2. Editorial 3. Medical cosmetology. The science of beauty products that must accompany any dermatology or aesthetic medicine procedure. Yvona Zivic. NP, MSc.

Accompanying any dermatology or aesthetic medicine procedure, so that it disrupts the patient's social life as little as possible, integrating anti-aging active ingredients targeting the mechanisms of skin aging, current cosmetology is the result of relevant and well thought-out upstream work, responding to a real demand in a highly competitive and globalized sector.

In its current definition, cosmetology is the science of studying beauty products, their formulation, their use and their effects.  We distinguish:

1. cosmetics which do not cross the dermal-epidermal junction but improve the appearance and protection of the skin and help maintain its good condition;
2. cosmeceuticals through the epidermis, capable of acting on the dermis with increasingly effective active ingredients in topical or oral form;
3. ldermatological products treating diseases by pharmacological action - medicine clearly distinguishing dermatology from cosmetology.

At the heart of this science we find assets such as :

1. vitamin C,
2. peptides,
3. aquaporin stimulators,
4. AHAs,
5. sodium hyaluronate,
6. ceramides,
7. polyphenols,
8. isoflavones
9. And other innovations.

 The biological effects of these active products, beyond the nutritional action, are quantified in vitro and in vivo, using skin cultures, clinical studies and biometric measurements. Tolerance tests, toxicity and efficacy studies are also an integral part of the specifications for cosmetic active ingredients, regulated in France by the DGCCRF. 

The development of a product containing these actives involves :

1. A formulation step
2. Verification of safety assays and toxicological data
3. Again, skin and eye tolerance tests (patch test, open test, use tests)
4. Stability tests or challenge test
5. Content/container compatibility tests
6. And a volunteer study to generate clinical data to support a specific claim with measurable evidence, if claimed.

The product information file (PIF), the declaration on the European portal (CPNP) and the validation of the compulsory mentions on the label are the last three regulatory steps for a finished product.

Skin aging reflects a disturbed homeostasis:

1. Less synthesis of collagen and elastin,
2. Less glycosaminoglycans - including hyaluronic acid
3. More proteolysis
4. More fragility
5. Less protection.

Patients complain:

1. The lack of texture of their skin
2. From the altered homogeneity of the complexion
3. Sagging tissues disturbing the definition of the contours
4. From the disruption of their facial volumes
5. And the appearance of the first wrinkles.

All these subjects are as many targets for aesthetic medicine acts but also for cosmetology actives aiming at :

1. Stimulate fibroblasts that play a major role in the production of essential elements of the extracellular matrix, such as type I and III collagen and elastin
2. In maintaining the structural integrity of the connective tissue
3. And in the stabilization of scars.

Cosmetology products are available in different galenic forms such as :

1. The solutions
2. Continuous or discontinuous dispersions (emulsions of aqueous, fatty, liposomal phases, suspensions, foams, aerosols),
3. Anhydrous forms (balms, sticks)
4. Or aqueous forms (gels and lotions)

They use many raw materials such as :

1. Water,
2. Alcohols (ethanol, glycerol, sorbitol.),
3. Lipidic compounds (fatty acids, vegetable or animal oils, butters, waxes, phospholipids, unsaponifiable matter),
4. The carbohydrate compounds (polysaccharides, glycoproteins.),
5. Protein compounds (collagen, elastin, keratin),
6. Nitrogenous compounds (amino acids), synthetic macromolecules (silicone, carbomers.),
7. Hydrocarbons (petroleum jelly, kerosenes.),
8. Vitamins (retinol, L-ascorbic acid,

α-tocopherol, pyridoxine...),

1. Organic extracts,
2. Aromas
3. and conservatives, for the main ones.

Thus, at the end of this chain of expertise, in order for the benefit to be real and perceptible to the patient, the cosmetic product will have gone through an arsenal of reflections and evaluations, allowing it to optimize the act of aesthetic medicine.