Polyhexamethylene biguanide

PHMB is a highly water soluble polyeleetrolyte. The structure of PHMB is shown below. 

PHMB is initially dosed at 10 ppm active (50 ppm product) and maintained in pools and spas between 6-10 ppm active (30-50 ppm as produet). It is typically consumed at a rate of 0.4 0.2 ppm/day. This can vary as a result of environmental faetors. It is topped-up when the level is at or below 6 ppm. This is accomplished about every 7-14 days. 

One property of PHMB that has received some consideration is the rate of kill. The AO AC method 965.13 measures the rate of kill of recreational water sanitizers under laboratory conditions in system devoid of organic 

PHMB because it is not an oxidizer will not bleach pool vinyl surfaces, degrade fabric or cause colors to fade in swimwear (Unhoch and Vore, 1996). An oxidizer is needed to assist in controlhng the accumulation of organics resulting from bathers and the environment. The preferred oxidizers for use with PHMB are peroxides, peracids, and perborates. Ozone can also be used to control the accumulation of organics in pool and spa water. Chlorine products cannot be used because they react with the PHMB removing it from the water as a sticky yellow precipitate. 

Other commonly used pool and spa chemicals incompatible with PHMB are anionic surfactants, phosphate-based chelating agents and copper algicides. 

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Interaction with the cervical mucus has been anticipated to be highest with cationic species [58], such as benzalkonium chloride, chlorhexidene, and vantocil (polyhexamethylene biguanide). A clear exception is the water-soluble sulfated polystyrene derivative (ORE 13904) [23]. In general, sperm penetration is lower for water-soluble cationic polymers than for anionic or nonionic polymers [59]. 

Larkin DF, Kilvington S, Dart JK. Treatment of Acanthamoeba keratitis with polyhexamethylene biguanide. Ophthalmology 1992 99(2) 185-191. 

Narasimhan S, Madhaven HN, Therese KL. Development and apphcation of an in vitro susceptibility test for Acanthamoeba species isolated from keratitis to polyhexamethylene biguanide and chlorhexidine. Cornea 2002 21(2) 203-205. 

Wallace, M.L., 2001. Testing the efficacy of polyhexamethylene biguanide as an antimicrobial treatment for cotton fabric. AATCC Rev. 1, 18-20. 

Benzyl dimethyl alkyl ammonium cUaide, dialkyl dimethyl ammonium chloride lauryl pyridinium chloride, cetyl pyridinium chloride, benzalkonium chloride Polyhexamethylene biguanide... 

Mills PC, Ahlstrom L, Wilson W (2005) Ototoxicity and tolerance assessment of a TrisEDTA and polyhexamethylene biguanide ear flush formulation in dogs. J Vet Pharmacol Ther 28 (4) 391-397. doi 10.1111/j. 1365-2885.2005.00672.x Mozayani A, Raymon L (2004) Handbook of drug interactions a clinical and forensic guide. Humana Press, Totowa... 

Polyhexamethylene Biguanide [II, 18.3.3.] Pool/Spa Sanitizer/Algistat 6.0-10.Oppm as active Easy to handle Completely water soluble Does not effect water balance Stable to sunlight Effective over wide pH range Shelf-life stable Effective in presence of high organic load Requires a separate oxidizer Increases maintenance of filter More expensive than chlorine products... 

Unhoch, M. J. Roy, D. V. and Lee, P. S. K., 1996. Stability of Swimming Pool/Spa Sanitizers Comparative Chemical Stability of Polyhexamethylene Biguanide and Hypochlorous Acid. J. Swimming Pool and Spa Industry 2 18-25. 

Biguanides (II, 18.3.). A polyhexamethylene biguanide is marketed by Avecia in the product Reputex. Several studies on the effects of this compound are published by Yang (Yang et al., 2000) and Huang (Huang et al., 2000). 

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