Cetylpyridinium chloride

Cetylpyridinium chloride (CPC) is a cationic quaternary ammonium compound used in some types of mouthwashes, toothpastes, lozenges, throat sprays, breath sprays, and nasal sprays. It is an antiseptic that kills bacteria and other microorganisms. It has been shown to be effective in preventing dental plaque and reducing gingivitis. It has also been used as an ingredient in certain pesticides. 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.

Cetylpyridinium chloride

Names
Preferred IUPAC name 1-Hexadecylpyridin-1-ium chloride
Other names Acetoquat CPC; Pyrisept EXADECYL-PYRIDINIUM, CHLORIDE
Identifiers
CAS Number	123-03-5 Y 6004-24-6 (monohydrate) D08AJ03 (WHO), D09AA07 (WHO) (dressing), R02AA06 (WHO) Y
3D model (JSmol)	Interactive image
Beilstein Reference	3578606
ChEBI	CHEBI:32915 Y
ChEMBL	ChEMBL34833 Y
ChemSpider	28979 Y
ECHA InfoCard	100.004.177
PubChem CID	31239
UNII	6BR7T22E2S Y D9OM4SK49P (monohydrate) Y
CompTox Dashboard (EPA)	DTXSID6041761
InChI InChI=1S/C21H38N.ClH/c1-2-3-4-5-6-7-8-9-10-11-12-13-14-16-19-22-20-17-15-18-21-22;/h15,17-18,20-21H,2-14,16,19H2,1H3;1H/q+1;/p-1 Y Key: YMKDRGPMQRFJGP-UHFFFAOYSA-M Y InChI=1/C21H38N.ClH/c1-2-3-4-5-6-7-8-9-10-11-12-13-14-16-19-22-20-17-15-18-21-22;/h15,17-18,20-21H,2-14,16,19H2,1H3;1H/q+1;/p-1 Key: YMKDRGPMQRFJGP-REWHXWOFAU
SMILES [Cl-].[n+]1(ccccc1)CCCCCCCCCCCCCCCC
Properties
Chemical formula	C21H38ClN
Molar mass	339.99 g·mol−1
Appearance	Solid
Melting point	77 °C (171 °F; 350 K)
Pharmacology
ATC code	B05CA01 (WHO)
Hazards
Lethal dose or concentration (LD, LC):
LD50 (median dose)	36 mg/kg (rabbit, iv) 400 mg/kg (rabbit, oral) 6 mg/kg (rat, ip) 30 mg/kg (rat, iv) 200 mg/kg (rat, oral) 250 mg/kg (rat, sc) 10 mg/kg (mouse, ip) 108 mg/kg (mouse, oral)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

The name breaks down as:

1. cetyl- refers to the cetyl group, named for its relation to cetyl alcohol, which was first isolated from whale oil (Latin: cetus);
2. pyridinium refers to the cation [C₅H₅NH]⁺, the conjugate acid of pyridine;
3. chloride refers to the anion Cl⁻.