Cationic emulsifiers

Cationic (or ionic) emulsifiers are emulsifiers that have a positively charged functional group, but not additionally a negatively charged group. Like any emulsifier, cationic emulsifiers are composed of a polar and a non-polar part. Different alkyl groups serve as the non-polar part. The polar group is usually a quaternary ammonium unit, so they are often tetraalkylammonium salts. Cationic emulsifiers are also called inverter soaps.

In pharmaceutical preparations, however, cationic emulsifiers are used less in their emulsifier function. They are rather used due to their antimicrobial effect. Examples are ammonium compounds such as benzalkonium chloride, cetylpyridinium chloride.