Chemical Properties
White Solid
Originator
Parfenac,Lederle,UK,1973
Uses
antiinflammatory, analgesic, antipyretic
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.
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.
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.
