Cetylpyridinium chloride (CPC) is a cationic quaternary ammonium compound used in some types of mouthwashes,

toothpaste Toothpaste is a paste or gel dentifrice used with a toothbrush to clean and maintain the aesthetics and health of teeth. Toothpaste is used to promote oral hygiene: it is an abrasive that aids in removing dental plaque and food from the teeth, a ...

lozenge Lozenge or losange may refer to: * Lozenge (shape), a type of rhombus *Throat lozenge, a tablet intended to be dissolved slowly in the mouth to suppress throat ailments *Lozenge (heraldry), a diamond-shaped object that can be placed on the field of ...

s, throat sprays, breath sprays, and

nasal spray Nasal sprays are used to deliver medications locally in the nasal cavities or systemically. They are used locally for conditions such as nasal congestion and allergic rhinitis. In some situations, the nasal delivery route is preferred for syste ...

s. It is an antiseptic that kills bacteria and other microorganisms. It has been shown to be effective in preventing dental plaque and reducing

gingivitis Gingivitis is a non-destructive disease that causes inflammation of the gums. The most common form of gingivitis, and the most common form of periodontal disease overall, is in response to bacterial biofilms (also called plaque) that is attached ...

. It has also been used as an ingredient in certain

pesticide Pesticides are substances that are meant to control pests. This includes herbicide, insecticide, nematicide, molluscicide, piscicide, avicide, rodenticide, bactericide, insect repellent, animal repellent, microbicide, fungicide, and lampri ...

s. Though one study seems to indicate cetylpyridinium chloride does not cause brown tooth stains, at least one mouthwash containing CPC as an active ingredient bears the warning label "In some cases, antimicrobial rinses may cause surface staining to teeth," following a failed class-action lawsuit brought by customers whose teeth were stained. The name breaks down as: # cetyl- means cetyl group, which derives from

cetyl alcohol Cetyl alcohol , also known as hexadecan-1-ol and palmityl alcohol, is a C-16 fatty alcohol with the formula CH3(CH2)15OH. At room temperature, cetyl alcohol takes the form of a waxy white solid or flakes. The name cetyl derives from the whale oi ...

that was first isolated from the

whale oil Whale oil is oil obtained from the blubber of whales. Whale oil from the bowhead whale was sometimes known as train oil, which comes from the Dutch word ''traan'' ("tears, tear" or "drop"). Sperm oil, a special kind of oil obtained from the ...

( la, cetus); # pyridinium refers to the

cation An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convent ...

₅H₅NHsup>+, the

conjugate acid A conjugate acid, within the Brønsted–Lowry acid–base theory, is a chemical compound formed when an acid donates a proton () to a base—in other words, it is a base with a hydrogen ion added to it, as in the reverse reaction it loses a ...

pyridine Pyridine is a basic heterocyclic organic compound with the chemical formula . It is structurally related to benzene, with one methine group replaced by a nitrogen atom. It is a highly flammable, weakly alkaline, water-miscible liquid with a d ...

; # chloride refers to the

anion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convent ...

Cl⁻.

Medical use

OTC (Over The Counter) products containing cetylpyridinium chloride include oral wash, oral rinse, and ingestable products, such as lozenges and over-the-counter cough syrup. The United States' federal Food and Drug Administration's monograph on oral antiseptic drug products reviewed the data regarding CPC and made this conclusion: The National Library of Medicine Toxicology Data Network (TOXNET) reviewed the range of toxicity of CPC and stated "Significant toxicity is rare after exposure to low concentration products that are typically available in the home."National Library of Medicine Toxicology Data Network
/ref> The fatal dose in humans ingesting cationic detergents has been estimated to be 1 to 3 g. Therefore, a person using a typical oral ingestible product that provides 0.25 mg CPC per dose would need to take 4,000 doses at one time to reach the estimated fatal dose range. A review found that mouthwashes containing CPC "provide a small but significant additional benefit when compared with toothbrushing only or toothbrushing followed by a placebo rinse" in reducing plaque and gingivitis-inflammation. In combination with chlorhexidine and zinc lactate, CPC has been found to be effective in treating

halitosis Bad breath, also known as halitosis, is a symptom in which a noticeably unpleasant breath odour is present. It can result in anxiety among those affected. It is also associated with depression and symptoms of obsessive compulsive disorder. Th ...

. CPC mouthwashes inactivate viruses, including Covid viruses, by breaking their lipid envelope.

Side effects

Tooth staining

Cetylpyridinium chloride is known to cause tooth staining in approximately 3 percent of users. The Crest brand has noted that this staining is actually an indication that the product is working as intended, as the stains are a result of bacteria dying on the teeth. Crest stated that because of the low incidence of staining, there was no need to label Pro-Health mouthwash as a potential tooth stainer. However, after numerous complaints and a federal class-action lawsuit, which was later dismissed, the mouthwash now contains a label warning consumers of its potential to stain teeth.

Temporary loss of taste

In a small percentage of population, CPC can alter or eliminate the sense of taste. The effect generally goes away a few days after discontinuing use of the product.

Toxicology and pharmacology

The of cetylpyridinium chloride has been measured at 30 mg/kg in

rats Rats are various medium-sized, long-tailed rodents. Species of rats are found throughout the order Rodentia, but stereotypical rats are found in the genus ''Rattus''. Other rat genera include ''Neotoma'' (pack rats), ''Bandicota'' (bandicoot ...

and 36 mg/kg in

rabbits Rabbits, also known as bunnies or bunny rabbits, are small mammals in the family Leporidae (which also contains the hares) of the order Lagomorpha (which also contains the pikas). ''Oryctolagus cuniculus'' includes the European rabbit specie ...

when the chemical is administered by

intravenous infusion Intravenous therapy (abbreviated as IV therapy) is a medical technique that administers fluids, medications and nutrients directly into a person's vein. The intravenous route of administration is commonly used for rehydration or to provide nutrie ...

but 200 mg/kg in rats, 400 mg/kg in rabbits, and 108 mg/kg in

mice A mouse ( : mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus' ...

when administered orally.

Chemistry

The molecular formula of cetylpyridinium chloride is C₂₁H₃₈NCl. In its pure form it is a

solid Solid is one of the State of matter#Four fundamental states, four fundamental states of matter (the others being liquid, gas, and Plasma (physics), plasma). The molecules in a solid are closely packed together and contain the least amount o ...

room temperature Colloquially, "room temperature" is a range of air temperatures that most people prefer for indoor settings. It feels comfortable to a person when they are wearing typical indoor clothing. Human comfort can extend beyond this range depending on ...

. It has a melting point of 77 °C when

anhydrous A substance is anhydrous if it contains no water. Many processes in chemistry can be impeded by the presence of water; therefore, it is important that water-free reagents and techniques are used. In practice, however, it is very difficult to achie ...

or 80–83 °C as a

monohydrate In chemistry, a hydrate is a substance that contains water or its constituent elements. The chemical state of the water varies widely between different classes of hydrates, some of which were so labeled before their chemical structure was underst ...

. It is soluble in water but insoluble in

acetone Acetone (2-propanone or dimethyl ketone), is an organic compound with the formula . It is the simplest and smallest ketone (). It is a colorless, highly volatile and flammable liquid with a characteristic pungent odour. Acetone is miscib ...

acetic acid Acetic acid , systematically named ethanoic acid , is an acidic, colourless liquid and organic compound with the chemical formula (also written as , , or ). Vinegar is at least 4% acetic acid by volume, making acetic acid the main component ...

, or

ethanol Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an Alcohol (chemistry), alcohol with the chemical formula . Its formula can be also written as or (an ethyl ...

. It has a

-like odor. It is combustible. Concentrated solutions are destructive to mucous membranes. Its critical micelle concentration (CMC) is ~ 0.0009–0.0011 M, and is strongly dependent on the salt concentration of the solution. Some products are formulated instead with the bromide

salt Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quantitie ...

cetylpyridinium bromide, the properties of which are virtually identical.

Compendial status

Food Chemicals Codex The Food Chemicals Codex (FCC) is a collection of internationally recognized standards for the purity and identity of food ingredients. Scope The FCC features more than 1,250 monographs, including food-grade chemicals, processing aids, foods (suc ...

* United States Pharmacopeia 31 * British Pharmacopoeia 1998

References

External links

Material Safety Data Sheet

* {{DEFAULTSORT:Cetylpyridinium Chloride Antiseptics Preservatives Chlorides Pyridinium compounds Cationic surfactants