Polyaminopropyl biguanide

Polyaminopropyl biguanide (PAPB) is a polymer containing biguanide group connected with a three methylene (propyl) linker. The polymer is a propyl analogue of polyhexamethylene biguanide. The polymer display some antibacterial activity however much lower than PHMB. As of May 2024, PAPB is not approved as a biocidal active substance under EU regulations.

Name controversy
In some sources, particularly in lists of cosmetic ingredients (INCI), the name polyaminopropyl biguanide is wrongly associated with polyhexamethylene biguanide (PHMB)