123-03-5

Production Methods

Cetylpyridinium chloride is prepared from cetyl chloride by treatment with pyridine.

Flammability and Explosibility

Nonflammable

Pharmaceutical Applications

Cetylpyridinium chloride is a quaternary ammonium cationic surfactant, used in pharmaceutical and cosmetic formulations as an antimicrobial preservative. 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. Mouthwashes containing cetylpyridinium chloride have been shown to inhibit plaque formation,(1–3) although efficacy is variable owing to limited published data.

Safety Profile

Poison by ingestion, intraperitoneal, subcutaneous, and intravenous routes. Moderately toxic by skin contact. A skin and eye irritant. When E heated to decomposiuon it emits very toxic fumes of NOx and Cl-.

Safety

Cetylpyridinium chloride is used widely in mouthwashes as a bactericidal antiseptic. It is generally regarded as a relatively nontoxic material when used at a concentration of 0.05% w/v, although minor side effects such as mild burning sensations on the tongue have been reported. 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 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

storage

Cetylpyridinium chloride is stable under normal conditions. It should be stored in well-closed containers.

Incompatibilities

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. The cetylpyridinium chloride ion also interacts with gelatin, resulting in reduced bioavailability.

Regulatory Status

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.

Definition

ChEBI: A pyridinium salt that has N-hexadecylpyridinium as the cation and chloride as the anion. It has antiseptic properties and is used in solutions or lozenges for the treatment of minor infections of the mouth and throat.

Brand name

Ceepryn (Marion Merrell Dow); Cepacol (Marion Merrell Dow).