Selection of cosmetic preservatives(二）
7)in addition to benzoic acid
One of the more representative ones is phenoxyethanol, which is a good solvent and preservative. It is often used as a solvent in the preparation of preservatives to dissolve other oil-soluble preservatives, but it can be used as an emulsifier. Therefore, it is necessary to consider its impact on the product itself when using it. It should also be noted that phenoxyethanol is unstable at some high pH values.
8) Benzoic Acid/Sodium Benzoate/Potassium Sorbate
Benzoic acid/sodium benzoate/potassium sorbate are mostly used in food, so they are listed together. Its antiseptic action mechanism is: benzoic acid preservatives act on their undissociated molecules. Undissociated benzoic acid has strong lipophilicity and is easy to pass through the cell membrane, enter the cell, and interfere with the permeability of the cell membrane of microorganisms such as mold and bacteria. , hinder the absorption of amino acids by the cell membrane, enter the benzoic acid molecule in the cell, acidify the alkali storage in the cell, inhibit the activity of the respiratory enzyme system in the microbial cell, and thus play a preservative role.
These preservatives also belong to the class effective in acidic systems. Sorbic acid and benzoic acid are inactive at pH 7 and exhibit 37% and 13% activity at pH 5, respectively, so they should be used in acidic media.
9) Bronopol
Bronopol is the abbreviation of 2-bromo-2-nitro-1,3-propanediol, which has a broad-spectrum antibacterial effect and can effectively inhibit most bacteria, especially Gram-negative bacteria. Works great. Instable under high temperature and alkaline conditions, under sunlight
The color becomes darker. Bropol can be compatible with most surfactants, but when it contains -SH group in cosmetic raw materials, such as cysteine, it will reduce the antibacterial activity of Bropol. In addition, metal aluminum can also reduce the bacteriostatic activity of Bropol.
10) IPBC
The English name of IPBC is 3-iodo-2-propynyl-butyl-carbamate. The main component is butyl iodopropynyl carbamate, which has broad-spectrum antibacterial activity, especially against mold and yeast. It has good compatibility and can be compatible with various components in cosmetics. The test results show that its antibacterial ability is not affected by additives such as surfactants, proteins and Chinese herbal medicines in cosmetics.
11) Trichlorosine
Triclosan's INCI name is Triclosan, and it can be used as a preservative in low doses. When the dosage is high, it has extensive and efficient killing and inhibitory effects on gram-negative bacteria, fungi, yeast and viruses (such as A, hepatitis B, rabies, HIV) that cause infection or pathogenicity, so it can be Also used in disinfection products.
In high concentration dosage, it is used as a bactericide, and its mechanism is that it can directly destroy the bacterial cell membrane, causing irreversible denaturation of proteins and nucleic acids in the cytoplasm, resulting in the exudation of low molecular weight intracellular lysates and bacterial death.
When used at low concentrations, it is used as a bacteriostatic agent. Its mechanism is to act on the bacterial cell membrane to hinder the absorption of nutrients such as amino acids and uracil that are necessary for the growth of bacteria, thereby inhibiting the production of bacteria. ) can play this role.
There are many types of preservatives, too many to enumerate. Here is a list of the more commonly used types in the field of cosmetics. In general, most preservatives are sensitive to strong redox chemicals, because they interfere with cell metabolism and damage cell structure through chemical reactions with various targets in microbial cells. Quaternary ammonium salts are preservative by affecting the osmotic pressure of microbial cells. When using preservatives, the influence of each component in the formula on the preservatives should be considered, so that the preservatives can play the greatest role.
4. No added preservatives
With the advancement of scientific research, the industry's research on the safety of preservatives has become more and more in-depth. Many traditionally used preservatives have been proven to have certain negative effects. Therefore, the product concept of safe "no added" preservatives has been very popular in the market since it was introduced from Japan in recent years. It is only due to technical reasons that it has not yet been fully popularized. However, if one day, formulators solve the anti-microbial problem of preservative-free systems, it is believed that "additive-free" products will occupy a larger market share.
