Name: Cetylpyridinium Chloride
CAS No: 1-Hexadecylpyridinium chloride [123-03-5], 1-Hexadecylpyridinium chloride monohydrate [6004-24-6]
BP: Cetylpyridinium Chloride PhEur: Cetylpyridinium Chloride USP: Cetylpyridinium Chloride
C16-alkylpyridinium chloride; Cepacol; Cepacol chloride; Cetamiun; cetylpridinii chloridum; cetyl pyridium chloride; Dobendan; hexadecylpyridinium chloride; 1-hexadecylpyridinium chloride; Medilave; Pristacin; Pyrisept.
1-Hexadecylpyridinium chloride [123-03-5], 1-Hexadecylpyridinium chloride monohydrate [6004-24-6]
C21H38ClN 339.9 (for anhydrous) C21H38ClNH2O 358.1 (for monohydrate)
Cetylpyridinium chloride is a quaternary ammonium cationic surfactant, used in pharmaceutical and cosmetic formulations as an antimicrobial preservative; see Section 10. It is used therapeutically as an antiseptic agent; used alone or in combination with other drugs for oral and throat care; used in nonparenteral formulations licensed in the UK; and used in oral and inhalation preparations at concentrations of 0.02–1.5 mg (see Section 16). Mouthwashes containing cetylpyridinium chloride have been shown to inhibit plaque formation,(1–3) although efficacy is variable owing to limited published data.(4,5)
Cetylypyridinium chloride is a white powder with a characteristic odor. It is slightly soapy to the touch.
See Table I.
Antibacterial activity Bactericidal to Gram-positive bacteria; relatively ineffective against some Gram-negative bacteria.(6) Cetylpyridinium chloride is also antibacterial against a number of oral bacteria;(7) see Table II.(8) Melting point 80–838C Solubility Freely soluble in water; very soluble in chloroform; very slightly soluble in ether; insoluble in acetone, acetic acid, and ethanol. Critical micelle concentration 0.34 g/L (water, 258C).(9,10)
Cetylpyridinium chloride is stable under normal conditions. It should be stored in well-closed containers.
Incompatible with strong oxidizing agents and bases. It is also incompatible with methylcellulose. Magnesium stearate suspensions in cetylpyridinium chloride have been shown to significantly reduce its antimicrobial activity. This is due to the absorption of cetylpyridinium chloride on magnesium stearate.(11) The cetylpyridinium chloride ion also interacts with gelatin, resulting in reduced bioavailability.(12)
Cetylpyridinium chloride is prepared from cetyl chloride by treatment with pyridine.
Cetylpyridinium chloride is used widely in mouthwashes as a bactericidal antiseptic. It is generally regarded as a relatively lthough minor side effects such as mild burning sensations on the tongue have been reported.(13) At higher concentrations, cetylpyridinium chloride may damage the mucous membranes in the mouth. It is harmful when ingested or inhaled. It can cause eye irritation, and is irritant to the respiratory system and the skin. LD50 (rat, IP): 0.006 g/kg(14) LD50 (rat, IV): 0.03 g/kg LD50 (rat, oral): 0.2 g/kg LD50 (rat, SC): 0.25 g/kg LD50 (mouse, IP): 0.01 g/kg LD50 (mouse, oral): 0.108 g/kg LD50 (rabbit, oral): 0.4 g/kg LD50 (rabbit, IV): 0.036 g/kg
Observe normal precautions appropriate to the circumstances and quantity of the material handled. When significant quantities are being handled, the use of a respirator with an appropriate gas filter is advised. When heated to decomposition, cetylpyridinium chloride emits very toxic fumes of NOx and Cl- . Eye protection, gloves and adequate ventilation are recommended
Included in nonparenteral formulations licensed in the UK. Included in the FDA Inactive Ingredients Database, for use in inhalation and oral preparations. Reported in the EPA TSCA Inventory. It is not approved for use in Japan. Included in the Canadian List of Acceptable Non-medicinal Ingredients.
Cetylpyridinium bromide. Cetylpyridinium bromide Empirical formula C21H38BrN Molecular weight 384.45 CAS number [140-72-7] Synonyms Aceloquat CPB; Bromocet; Cetapharm; Cetasol; Ncetylpyridinium bromide; hexadexylpyridinium bromide; Nitrogenol; Seprison; Sterogeno
Cetylpyridinium chloride has also been studied for use as an antimicrobial preservative for meat(15) and vegetables.(16) However, the residual levels after treatment are considered excessive for human consumption; see Section 14. The EINECS number for cetylpyridinium chloride is 204-593-9. The PubChem Compound ID (CID) for cetylpyridinium chloride monohydrate is 22324