Dibenzoyl peroxide

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Structural formula
Structure of dibenzoyl peroxide
General
Surname Dibenzoyl peroxide
other names
  • Benzoyl peroxide
  • BPO
  • DBPO
Molecular formula C 14 H 10 O 4
Brief description

colorless powder with a faint odor

External identifiers / databases
CAS number 94-36-0
EC number 202-327-6
ECHA InfoCard 100.002.116
PubChem 7187
ChemSpider 6919
DrugBank DB09096
Wikidata Q411424
Drug information
ATC code

D10 AE01

Drug class

Acne medication

properties
Molar mass 242.23 g mol −1
Physical state

firmly

density

1.33 g cm −3 (25 ° C)

Melting point

Decomposition from 70 ° C

Vapor pressure

<10 Pa

solubility
safety instructions
Please note the exemption from the labeling requirement for drugs, medical devices, cosmetics, food and animal feed
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary
01 - Explosive 02 - Highly / extremely flammable 07 - Warning 09 - Dangerous for the environment

danger

H and P phrases H: 241-317-319-410
P: 210-261-273-280-305 + 351 + 338-333 + 313-420-501
MAK

DFG / Switzerland: 5 mg m −3 (measured as inhalable dust )

Toxicological data

7710 mg kg −1 ( LD 50 ,  rat ,  oral )

As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

(Di) Benzoyl peroxide is a colorless powder with a faint odor. It belongs to the organic peroxides . The powder falls within the scope of the Explosives Act and is classified in Annex II into substance group B.

history

Dibenzoyl peroxide was one of the first organic peroxides to be synthesized. It was first described by BC Brodie in 1858 . The first industrial use began around 1900 as a bleach . With the increased emergence of synthetic plastics from 1940 on, the use of the substance as a radical initiator for polymerization reactions of vinyl monomers increased .

Manufacturing

Benzoyl peroxide can be made from benzoyl chloride and sodium peroxide or hydrogen peroxide .

Synthesis of benzoyl peroxide

properties

The bond between the two oxygen atoms is unstable and splits homolytically with low expenditure of energy, e.g. B. by light irradiation (photolytic) or supply of heat (thermolytic). The formation of benzoyloxy radicals plays an important role in the radical polymerization of alkenes :

Decomposition of DBPO photolytically or thermally

Benzoyl peroxide breaks down easily into two benzoyloxy radicals , which further break down into phenyl radicals with splitting off of CO 2 . The phenyl radicals can then dimerize to biphenyl :

Decarboxylation and dimerization

In the dermatological application, it may therefore be phototoxic come effects. As a potent oxidizing agent, benzoyl peroxide has an antibacterial and keratolytic effect . The amino acids of the bacteria are oxidized. After the release of benzoic acid and oxidative cleavage of the lipid bridges of the keratin , keratolysis occurs. By reducing free oxygen radicals , there is also an anti-inflammatory effect .

Benzoyl peroxide can explode if heated. Therefore, commercially available benzoyl peroxide always contains phlegmatizers (e.g. 20% water) or plasticizers for stabilization.

use

Benzoyl peroxide is used as an active ingredient in dermatology and here in particular in the topical therapy of acne . Benzoyl peroxide preparations are available without a prescription in concentrations of up to 10% in many countries - not in Austria or Switzerland.

Cosmetic articles must not contain benzoyl peroxide.

In organic chemistry , benzoyl peroxide is used as a radical starter z. B. for radical polymerizations , used (for example in synthetic resins based on methyl methacrylate to create industrial floors or as a component of two-component adhesives ). Benzoyl peroxide is no longer used industrially as an initiator in acrylic resin production, since then approx. 0.2% (toxic) benzene is contained as a decomposition product in the synthetic resins. As an alternative z. B. dicumyl peroxide is used.

See also

Trade names

As a medicine

Monopreparations

Aknefug BP (CH), Aknefug oxide (D), Akneroxid (A, D, CH), Benzac (CH), Benzaknen (D), Benzoyt (D), Brevoxyl (D), Cordes BPO (D), Klinoxid (D ), Lubexyl (CH), Marduk (D), PanOxyl (D), Sanoxit (D)

Combination preparations

Acne Crème plus (CH), Acne Plus (A, D), Duac (D), Epiduo (D, CH)

As a radical starter

Basiron, Stioxyl, Panoxyl, Perkadox L-W75

Individual evidence

  1. ↑ a b c d e f g h i Entry on dibenzoyl peroxide in the GESTIS substance database of the IFA , accessed on January 10, 2017(JavaScript required) .
  2. ↑ a b c d e f g Entry on benzoyl peroxide. In: Römpp Online . Georg Thieme Verlag, accessed on January 29, 2017.
  3. ↑ Entry on dibenzoyl peroxide in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
  4. ↑ Schweizerische Unfallversicherungsanstalt (Suva): Limit values ​​- current MAK and BAT values (search for 94-36-0 or dibenzoyl peroxide ), accessed on November 2, 2015.
  5. ^ Sprengstoffgesetz - SprengG , accessed on November 4, 2018
  6. ^ BC Brodie: Justus Liebigs Ann. Chem. 108 (1858) 79.
  7. ↑ a b c H. Klenk; PH Goetz; R. Siegmeier; W. Mayr: Organic Peroxy Compounds , in: Ullmanns Enzyklopädie der Technischen Chemie , Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 2012; doi : 10.1002 / 14356007.a19_199 .
  8. ↑ Fanta, D., Messeritsch-Fanta, C .: Acne 1999: do we still need a dermatologist? In: dermatologist . tape 50 , no. December 12 , 1999, pp. 900-11 , doi : 10.1007 / s001050051009 .
  9. ↑ Red List online, as of September 2009.
  10. ↑ AM comp. d. Switzerland, as of September 2009.