Absorption, Distribution and Excretion
Method of application affects the extent of cutaneous absorption. Following rectal administration as suppositories, the systemic absorption was reported to be low.
Following topical administration of 5% bufexamac, the recovery in the urine was 3.5% of the applied dose within 144 hours. Studies in healthy volunteers receiving an oral dose of 125 to 500 mg indicate that an average of 80% of the total dose is excreted in the urine within 48 hours.
No data available.
No data available.

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Metabolism / Metabolites
No data available.

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Biological Half-Life
No data available.

Protein Binding
No data available.

[1]. Chemoproteomics profiling of HDAC inhibitors reveals selective targeting of HDAC complexes. Nat Biotechnol. 2011 Mar;29(3):255-65.

[2]. Histone deacetylase 10 promotes autophagy-mediated cell survival. Proc Natl Acad Sci U S A. 2013 Jul 9;110(28):E2592-601.

[3]. Bufexamac ameliorates LPS-induced acute lung injury in mice by targeting LTA4H. Sci Rep. 2016 Apr 29;6:25298.

[4]. Acetylation site specificities of lysine deacetylase inhibitors in human cells. Nat Biotechnol. 2015 Apr;33(4):415-23.

[5]. Effects of intra-articular injections of bufexamac suspension in healthy horses. Am J Vet Res. 2001 Oct;62(10):1629-35.

Bufexamac is 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. It has a role as a non-narcotic analgesic, a non-steroidal anti-inflammatory drug and an antipyretic. It is a hydroxamic acid and an aromatic ether.
Bufexamac is a non-steroidal anti-inflammatory drug (NSAID) under the market name Droxaryl, Malipuran, Paraderm and Parfenac. It is typically administered topically for the treatment of subacute and chronic eczema of the skin, including atopic eczema and other inflammatory dermatoses, as well as sunburn and other minor burns, and itching. It has also been used in suppositories in combination with local anaesthetics indicated for haemorrhoids. The use of bufexamac has been discontinued in Canada and the United States, which may be due to undetermined clinical efficacy and a high prevalence of contact sensitization. Bufexamac was also withdrawn by the EMA in April 2010.
A benzeneacetamide with anti-inflammatory, analgesic, and antipyretic action. It is administered topically, orally, or rectally.

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Drug Indication
Indicated for the treatment of various skin conditions, such as atopic eczema and other inflammatory dermatoses.

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Mechanism of Action
The full mechanism of action is unclear. It is proposed that bufexamac acts similarly to other non-steroidal anti-inflammatory drugs to inhibit prostaglandin biosynthesis _in vitro_, via inhibiting cyclo-oxygenase (COX) enzymes. Systematically administered bufexamac may accumulate preferentially in the adrenal cortex of rats and may play a role in adrenal stimulation; however its topical anti-inflammatory action is likely to be independent of this effect.

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Pharmacodynamics
Bufexamac is a topically-active anti-inflammatory agent that inhibits the cyclooxygenase enzyme. In cutaneous and deep experimental inflammation, topical administration of bufexamac exerted a dose-related anti-inflammatory effect. In guinea pigs, bufexamax was shown to be more active than topical acetylsalicylic acid 5% or phenylbutazone 5% in delaying the local increase in temperature resulting from UV exposure. Bufexamac is unlikely to have any effect on wound healing.

C12H17NO3

223.27

223.12

2438-72-4

2466

White to off-white solid powder

1.1±0.1 g/cm3

161 - 162ºC

1.530

1.7

2

3

6

16

200

0

MXJWRABVEGLYDG-UHFFFAOYSA-N

InChI=1S/C12H17NO3/c1-2-3-8-16-11-6-4-10(5-7-11)9-12(14)13-15/h4-7,15H,2-3,8-9H2,1H3,(H,13,14)

2-(4-butoxyphenyl)-N-hydroxyacetamide

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Solubility in Formulation 1: 2.5 mg/mL (11.20 mM) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), suspension solution; with sonication.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (11.20 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (11.20 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 4: 10 mg/mL (44.79 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with ultrasonication (<60°C).

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 (Please use freshly prepared in vivo formulations for optimal results.)