Carbamide peroxide

Carbamide peroxide
Identifiers
CAS number	124-43-6 Y
PubChem	31294
ChemSpider	29034 Y
UNII	31PZ2VAU81 Y
ATC code	D02AE01
Jmol-3D images	Image 1
SMILES O=C(N)N.OO
InChI InChI=1S/CH4N2O.H2O2/c2-1(3)4;1-2/h(H4,2,3,4);1-2H Y Key: AQLJVWUFPCUVLO-UHFFFAOYSA-N Y
Properties
Molecular formula	CH6N2O3
Molar mass	94.07 g mol−1
Appearance	White solid
Melting point	75-85 °C, 348-358 K, 167-185 °F
Hazards
MSDS	External MSDS
EU classification	Explosive, C
Pharmacology
Routes of administration	topical
Pregnancy category	C(US)
Y peroxide (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Carbamide peroxide, also called urea peroxide, urea hydrogen peroxide (UHP), and percarbamide, an adduct of hydrogen peroxide and urea. Like hydrogen peroxide, it is an oxidizer. This compound is a white crystalline solid which dissolves in water to give free hydrogen peroxide; the solubility of commercial samples varies from 0.05 g/mL^[1] to more than 0.6 g/mL.^[2] The chemical formula is CH₆N₂O₃.

Production

This compound is cheaply available; it is produced on a scale of several hundred tonnes a year by the dissolution of urea in excess concentrated hydrogen peroxide solution, followed by crystallization.^[3] The laboratory synthesis is analogous.^[4]

Applications

Carbamide peroxide is mainly used as a disinfecting and bleaching agent in cosmetics and pharmaceuticals.^[3] As a drug, this compound is used in some preparations for the whitening of teeth.^[3][5][6] It is also used to relieve minor inflammation of gums, oral mucosal surfaces and lips including canker sores and dental irritation,^[7] and to emulsify and disperse ear wax.^[7]

In tooth bleaching, the hydrogen peroxide produced acts to oxidise interprismatic extrinsic staining within tooth enamel. There are several methods of applying the peroxide gel to the tooth ranging from night-guard application at home or in-surgery application. The bleaching obtained is proportional to the length of time the peroxide is applied to the tooth, and the concentration used. Concentrations used for tooth whitening purposes range between 10% and 35%. Higher concentrations carry a higher risk of side effects such as chemical burns. 10% is widely regarded as safe.

A pharmaceutical company, Elorac, has performed clinical trials for the use of carbamide peroxide for the treatment of acne vulgaris.^[8]

In the laboratory, it is used as a more easily handled replacement for hydrogen peroxide.^[4][9]

Safety

As an oxidizer, this compound is a skin, eye and respiratory irritant. At higher concentrations, it is corrosive and may cause burns if not used properly. If too much gel is used and let in contact with skin or gums, there is a risk of white chemical burns called blanching.^{[citation needed]}

See also

• Sodium percarbonate

References

1. ^ Sigma-Aldrich specification sheet
2. ^ Chemicalland data sheet
3. ^ ^{a b c} Harald Jakob, Stefan Leininger, Thomas Lehmann, Sylvia Jacobi, Sven Gutewort (2005), "Peroxo Compounds, Inorganic", Ullmann's Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH, doi:10.1002/14356007.a19_177.pub2 
4. ^ ^{a b} Yu, Lei; Meng, Bo; Huang, Xian (2008). "Urea-Hydrogen Peroxide Complex: A Selective Oxidant in the Synthesis of 2-Phenylselenyl-1,3-butadienes". Synthetic Communications 38: 3142. doi:10.1080/00397910802109224. 
5. ^ Mokhlis, GR; Matis, BA; Cochran, MA; Eckert, GJ (2000). "A Clinical Evaluation of Carbamide Peroxide and Hydrogen Peroxide Whitening Agents during Daytime Use". Journal of the American Dental Association (1939) 131 (9): 1269–77. PMID 10986827. http://jada.ada.org/cgi/content/full/131/9/1269. 
6. ^ Toothwhitening from the UMD of New Jersey website
7. ^ ^{a b} Center for Integrative Medicine: Carbamide Peroxide from the University of Maryland Medical Center website
8. ^ Elorac Announces Clinical Results of Carbamide Peroxide Studies for the Treatment of Acne website
9. ^ Varma, Rajender S.; Naicker, Kannan P. (1999). "The Urea−Hydrogen Peroxide Complex: Solid-State Oxidative Protocols for Hydroxylated Aldehydes and Ketones (Dakin Reaction), Nitriles, Sulfides, and Nitrogen Heterocycles". Organic Letters 1: 189. doi:10.1021/ol990522n. 

External links

• http://www.organic-chemistry.org/chemicals/oxidations/hydrogenperoxide-urea-adduct.shtm
• "Carbamide Peroxide Monograph". Drugs.com. http://www.drugs.com/monograph/carbamide-peroxide.html.