Bufexamac Property

Melting point:

153-155°

Boiling point:

364.56°C (rough estimate)

Density 

1.1223 (rough estimate)

refractive index 

1.5300 (estimate)

storage temp. 

Inert atmosphere,Store in freezer, under -20°C

solubility 

Practically insoluble in water, soluble in dimethylformamide, slightly soluble in ethyl acetate and in methanol.

pka

9.24±0.20(Predicted)

color 

White to Off-White

Merck 

14,1474

CAS DataBase Reference

2438-72-4(CAS DataBase Reference)

Safety

WGK Germany 

2

RTECS 

AK8280000

HS Code 

2928.00.2500

Toxicity

LD50 orally in mice, rats: >8, >4 g/kg (Lambelin)

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H317May cause an allergic skin reaction

Precautionary statements

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P272Contaminated work clothing should not be allowed out of the workplace.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P501Dispose of contents/container to..…

Bufexamac Chemical Properties,Usage,Production

Chemical Properties

White Solid

Originator

Parfenac,Lederle,UK,1973

Uses

antiinflammatory, analgesic, antipyretic

Uses

Bufexamac is a specific inhibitor of class IIB histone deacetylases (HDAC6 and HDAC10). Bufexamac is a non-steroidal anti-inflammatory drug used topically as well as rectally. Formulations containing Bufexamac is used by many patients with eczematous disorders as an alternative to topical corticosteroids.

Uses

Bufexamac is a non-steroidal topical medication used for treatment of a variety of problems in which the skin is inflamed. These vary widely from insect bites to bums, plant stings and a wide variety of medical conditions induding psoriasis, hemorrhoidal symptoms, eczema and inflammation of the skin following radiotherapy. In this last case, it can be used before radiotherapy to help prevent inflammation of the skin caused by radiation therapy.

Definition

ChEBI: A hydroxamic acid derived from phenylacetamide in which the benzene moiety is substituted at C-4 by a butoxy group. It has anti-inflammatory, analgesic, and antipyretic properties.

Manufacturing Process

(1) 136 g of p-hydroxyacetophenone, 140 g of butyl bromide, 152 g of potassium carbonate, 17 g of potassium iodide and 275 cc of ethanol are mixed and then refluxed for 48 hours. The reaction mixture is cooled, diluted with water, then extracted with ether. The ethereal phase is washed with a 10% sodium hydroxide solution, then with water, followed by drying, ether is evaporated and the product distilled under reduced pressure. 168 g of pbutyloxyacetophenone are obtained with yield of 87% (160°-162°C at 11 mm Hg).
(2) 192 g of p-butyloxyacetophenone, 42 g of sulfur and 130 g of morpholine are mixed and then refluxed for 14 hours. The resulting solution is poured into water and stirred until crystallization of the sulfurated complex. The latter is filtered, washed with water and dried, Production: 270 g (88% yield). (3) 200 g of sodium hydroxide are dissolved in 1,500 cc of ethanol and then 293 g of the thus-obtained sulfurated complex are added. The mixture is refluxed overnight, The mixture is distilled to separate the maximum of the alcohol and then diluted with water. The resulting solution is acidified with hydrochloric acid, and extracted with ether. The ethereal phase is washed with water, followed by extraction with a 10% sodium carbonate solution. The carbonated solution is acidified with 10% hydrochloric acid, and the resulting precipitate of p-n-butyloxyphenylacetic acid is filtered and dried. 100 g of this product are obtained (70% yield).
(4) 208 g of p-n-butyloxyphenylacetic acid, 368 g of ethanol and 18 cc of sulfuric acid are refluxed for 5 hours. The mixture is diluted with water, after which it is extracted with ether. The ethereal phase is successively washed with water, then with carbonate, and again with water, following which it is dried and distilled to remove solvent. The ester is then distilled at a reduced pressure. 200 g of ethyl p-butyloxyphenylecetate are thus obtained with yield of 61% (186°C at 8 mm Hg).
(5) 7 g of hydroxylamine hydrochloride are dissolved in 100 cc of methanol. A solution of 5 g of sodium in 150 cc of methanol is added and the salt precipitate is separated by filtration. 22 g of ethyl p-n-butyloxyphenylacetate are added to the filtrate and the mixture is refluxed for 1 hour. The mixture is cooled and acidified with 20% hydrochloric acid. 14.7 g of p-nbutyloxyphenylacetohydroxamic acid are thus obtained with yield of 71% (melting point: 153°-155°C).

brand name

Anderm (Wyeth-Ayerst); Paraderm (Wyeth-Ayerst); Parfenac (Wyeth-Ayerst);Bufemac;Bufexamac-ratiopharm (r) creme;Bufexine ratiopharm(r) f-sable;Calmaderm;Droxan;Droxaryl zalf 50 mg;Duradermal;Flogocid gel n.n;Flogocid sable;Malipuran;Parafenac (r) milch;Parafenac 5% creme;Parafenac basishad;Parafenac sable;Parafenal;Parfenal creme derm;Viafen u est.crema 40 g.

Therapeutic Function

Antiinflammatory, Analgesic, Antipyretic

World Health Organization (WHO)

Bufexamac, an analgesic and anti-inflammatory agent, was introduced in 1974 for the topical treatment of a wide range of dermatoses. The drug is widely marketed and the World Health Organization is not aware of restrictive action having been taken elsewhere.

Contact allergens

Bufexamac is an arylacetic nonsteroidal anti-inflammatory drug. It induces allergic contact dermatitis, eczematous or erythema multiforme like type, and even generalized eruptions like acute generalized exanthematous pustulosis.