Cetylpyridinium chloride

• BPCetylpyridinium Chloride
• Ph. Eur.Cetylpyridinium Chloride
• USP–NFCetylpyridinium Chloride

CPC; cetylpyridinii chloridum; hexadecylpyridinium chloride; 1-hexadecylpyridinium chloride monohydrate; Cepacol; Dobendan

1-Hexadecylpyridinium chloride monohydrate · [123-03-5]

UNII 6BR7T22E2S · PubChem CID 31239

C21H38ClN·H2O · 358.01

Antimicrobial preservative

Typical concentrations: — · Dosage forms: Liquid

A quaternary ammonium cationic surfactant used as an antiseptic in mouthwashes (typically about 0.05–0.1% w/v), throat lozenges and toothpastes, and as an antimicrobial preservative at lower concentrations in some nasal, inhalation and topical products. It is also used as a cationic surfactant to solubilise drugs.

A white or almost white powder, slightly soapy to the touch, with a faint characteristic odour.

Melting point

about 80–83 °C

Solubility

soluble in water; very soluble in ethanol; slightly soluble in methylene chloride

Surface activity

cationic surfactant; aqueous solutions foam strongly on shaking

Antimicrobial spectrum

mainly Gram-positive bacteria and some yeasts; Gram-negative organisms, especially Pseudomonas, are less susceptible

Stable. Aqueous solutions can be sterilised by autoclaving. Store in a well-closed container, protected from light, in a cool, dry place.

Incompatible with soaps and other anionic surfactants, and with anionic polymers and dyes, which form complexes and inactivate it. High concentrations of non-ionic surfactants reduce its activity, and it can be adsorbed by some container materials and by fillers such as silica in toothpastes.

Prepared by reacting pyridine with cetyl chloride (1-chlorohexadecane) and crystallising the quaternary salt as the monohydrate.

Well tolerated at the concentrations used in oral care products, although regular use of mouthwashes may cause brown staining of the teeth, a burning sensation and taste disturbance. Concentrated solutions irritate the skin, eyes and mucous membranes, and swallowing large amounts can cause serious toxicity.

Observe normal precautions for the quantity handled. The powder is irritant to the eyes, skin and respiratory tract; wear eye protection and gloves and avoid inhaling the dust.

Included in the FDA Inactive Ingredient Database for non-parenteral products and in non-parenteral medicines licensed in Europe. It is also an active ingredient in over-the-counter oral antiseptic products.

Benzalkonium chloride; benzethonium chloride; cetrimide; cetylpyridinium bromide.

In toothpastes and mouthwashes the amount of free, bioavailable CPC matters more than the total content, because binding to anionic ingredients and abrasives can inactivate it; avoid sodium lauryl sulfate and anionic thickeners in such products.