Preservative selection principle for Cosmetics

 With the improvement of living standards, the public's requirements for the safety of cosmetics are also increasing, requiring products to be natural, mild, and non-irritating. However, cosmetics are products that are prone to spoilage, so in order to increase their useful life, preservatives are inevitably added. The so-called preservative refers to an additive that prevents the spoilage of cosmetics. In the product, the preservative acts to protect the product from microbial contamination, extend the shelf life of the product, ensure the safety of the product, and prevent the consumer from being contaminated by microorganisms. The product causes a possible infection.

Toiletries are an external product that does not meet the strict hygiene standards of the drug during production, packaging, and storage, and is less likely to be absolutely sterile. And most of the packaging is open. After opening, the bacteria will naturally contact the product with the air circulation, which will bring about artificial secondary pollution when the consumer uses it. At the same time, the product contains a lot of nutrients as microbial nutrients, if not With the addition of preservatives, the opened product will soon be filled with bacteria and their metabolites, which will have a negative impact on consumers' continued use of the product. However, preservatives have a certain potential irritant, and should not be added in excess, and the necessary minimum concentration can be maintained.

At present, in the care product, basically, it is still known as Carson (the main functional ingredients are methylisothiazolinone and methylchloroisothiazolinone), DMDMH (the main functional ingredients are hydantoin and formaldehyde). ), phenoxyethanol, benzoic acid, benzoic acid ester, potassium sorbate, parabens, IPBC (butyl iodopropynyl carbamate), etc., these preservatives are relatively Low quantity, high effect and low price.

Principles for selection of preservatives for toiletries

In the choice of preservative system, the composition of the toiletries or the physical and chemical properties of the raw materials should be taken into consideration. Considering the microbial factors and other factors, the ideal preservatives for the care products should have the following properties:

(1) Broad spectrum antibacterial activity;

(2) good compatibility;

(3) good safety;

(4) good water solubility (because most of the care products are aqueous substrates).

Preservative efficacy evaluation

The evaluation methods for the effectiveness of the preservative system include the USP (United States Pharmacopoeia) method, the CTFA (American Cosmetics, Toiletries and Fragrance Association) method, and the linear regression method. At present, the prevalence evaluation method commonly used at home and abroad is a one-time anti-corrosion challenge test recommended by CTFA. The method can simulate the potential of high-intensity microbial contamination during the production and use of cosmetics and the optimal conditions for microbial growth in the natural environment, so that the test results are closer to reality, so as to ensure that the product avoids the loss and protection caused by microbial contamination. Consumer health provides a reliable guarantee. That is, artificially inoculate a certain number of microorganisms in a sample to be tested, culture at an appropriate temperature, periodically separate the microorganisms of the sample, and evaluate the antibacterial efficacy of the sample according to the change in the number of microorganisms.