Cosmetic components: Preservatives

Preservatives in cosmetics are a frequent topic for discussions and speculation in the popular and scientific press. Preservatives should provide protection of the cream from a wide range of organisms (bacteria, fungi) for a long time. Cosmetic means are used for several months (and even years), therefore the maintenance of preservatives is those conditions of storage on which cosmetic means are calculated. However, most sterilization methods adopted in the food industry (lyophilization, sterilization of packaging, storage at low temperatures) are not suitable for cosmetic production. Therefore, at least for microbial cells, the preservative should definitely be toxic.

A preservative may exhibit toxicity also in relation to skin cells. Today, scientists are working to create preservatives with the widest possible spectrum of action, so that there is no need to introduce several preservatives into the formulation.

Preservatives are included in cosmetics whenever possible in a minimum concentration, at which they are effective against microbes and are not toxic to the skin. Once again, we note that in fact, undesirable skin reactions can cause absolutely any component of the cosmetic. Just some substances have a toxic potential higher than others. Preservatives along with surfactants are traditionally considered one of the main causes of allergic reactions and dermatitis in people with sensitive skin. Of course, there is some truth in this. Still, one can not disagree with the fact that preservatives are less harmful than microbes and microbial toxins, as well as products of decomposition of cosmetic ingredients by microbial flora. Therefore, preservatives in cosmetics should be, and they can not be abandoned completely.

Some natural components, such as plant extracts (birch leaves, pine bark and many other plants), sodium benzonate (contained in cranberries, currants), essential oils, propolis, salts, seaweed extract, rich in iodine, have the property of slowing the spoilage of cosmetic products. The introduction of these substances into the formulation makes it possible to reduce the concentration of synthetic preservatives (if the task is precisely this).

Cosmetics "without preservatives" can not be used for long, and store it better in the refrigerator. Otherwise, the growth of microbial flora is observed, as well as the inactivation of active additives.

As antibacterial additives are used not traditional cosmetic preservatives, but completely different compounds. Among them there are nonspecific bactericidal agents (ethyl alcohol, acetone, iodine containing compounds, plant extracts, essential oils, etc.) and specific substances that block a certain stage of the microbial cell metabolism (antibiotics).

There are several groups of cosmetics with antibacterial properties: anti-acne agents, anti-dandruff shampoos, antimicrobial soaps, antiperspirant deodorants. In this row, anti-acne drugs stand apart. First, they, as a rule, are not washed off and remain on the skin for a long time. Secondly, the skin on which they are applied has a damaged barrier and its own defense mechanisms are weakened; thirdly, dysbacteriosis accompanied by inflammation is often observed on the skin with acne. Therefore, cosmetics for the care of the problem skin of the skin has its own characteristics and comes very close to medical preparations.

As for other groups of antibacterial cosmetics, legislators from different countries evaluate them in different ways. So, in the USA the presence of antibacterial ingredients in cosmetic products immediately translates the drug from the category of cosmetic products into medicines. Deodorants in the US immediately become "medicines", as soon as it is announced that the antidiabetic effect is based on the deodorant effect. Therefore, antiperspirants in the United States are included in the category of medicines. A group of products represented by antibacterial soaps has become a bone of contention between the cosmetic industry and the FDA. The FDA decided that soaps marketed as antibacterial refer to medicines. Honestly, any soap has antibacterial properties, because the dominant components of soap are PAV.PAV in soap for the skin is not afraid, but the bacteria that are on its surface are dying.

The most well-known antibacterial component for soap is triclosan. In the media, there are periodic reports that triclosan is toxic to the skin. This is nothing more than another speculation, because to date none of the many large-scale studies have given this confirmation. But the question of the expediency of including triclosan in soap is quite natural, especially since there are additional reasons for this. To really effectively affect the microbial flora living on the surface of our skin, it is necessary to introduce an antimicrobial agent at a higher concentration. Thus, we increase the risk of adverse reactions (irritation, allergies), on the one hand, and completely without any basis seriously violate the microbiological balance, on the other.

And so the preservative should:

• A preservative or preservative system should be safe when the cosmetic product containing it is used for its intended purpose.
• A preservative or combination of preservatives should be compatible with all the ingredients of the system and should not lose activity due to interaction with other components. The introduction of preservatives should not affect the consumer properties of cosmetic products.
• An ideal preservative should not introduce a smell or color into the cosmetic product or react with the ingredients of the system, causing a discoloration or smell.
• The preservative should be stable at all temperatures and pH values that occur in the manufacture of cosmetics.
• The ideal preservative should work both in the production process and during the entire planned shelf life of cosmetics.

Particularly we emphasize that for the manufacturer of cosmetics the most important thing is the choice of preservative, which is really effective against microbes and is safe. Price is a secondary factor. Much more serious possible complaints from buyers or media, which can cause serious damage to the reputation of the cosmetic company. This will cost the company immeasurably more expensive than saving on a cheap preservative that will not work.

[1], [2], [3]