How is IPBC used as a cosmetic preservative?
Iodopropargyl butylcarbamate, INCI lodopropynyl butylcarbamate, or IPBC, is a halogenated unsaturated organic compound.
CAS No. : 55406-53-6
Molecular formula: C8H12INO2
The groups that have bactericidal effect are:
antiseptic
In the formula, R represents a substituted or unsubstituted alkyl, naphthenic, aromatic alkyl or aromatic group, which has 1 to 20 carbon atoms and contains m bonds. m and n are integers between 1 and 3.
Appearance: Off-white or white crystalline powder
Melting point: 55-56℃
The pH value of 0.1%IPBC solution is 4.5~5.5
IPBC is insoluble in water, with a solubility of 156mg/L in water at 20℃. It is soluble in aromatic and ethanol solvents, and easily soluble in surfactants, emulsifiers and polar solvents. Usually when we add it to a recipe we use propylene glycol to dissolve it before adding it.
IPBC has a broad spectrum of mildew resistance and is commonly formulated as a fungal inhibitor.
Nowadays, there are three types of principles of cosmetic preservatives recognized by the industry. One is to cause the permeability loss of membrane so that cell contents exudate and lose activity; The second type is to inhibit or damage the activity of important enzymes in the cell. Usually, the active site of the enzyme reacts with sulfhydryl or hydroxyl groups in the cell to inactivate the enzyme. The third is to destroy bacterial genetic material, tissue cell synthesis and physiological activities.
IPBC inhibits fungal action principle for the second type, inhibition of fungal important enzyme activity.
IPBC is often used in combination with antimicrobial preservatives such as imidazolidyl urea and bimethylol imidazolidyl urea.
The properties of IPBC are stable under strong oxidants, but it is not stable in strong reducing agents, strong acids and strong bases, so it is required to add it at pH=4~9 and temperature below 40℃.
The following figure shows the requirements of IPBC in the European Union Cosmetic Regulations (picture from the Evolution of the Characteristics and Regulations of Preservatives in Cosmetics).
