Absorption, Distribution and Excretion
/In rats/ Flufenoxuron exhibited a dose-dependant absorption following a single low dose (3.5 mg/kg) or single high dose (350 mg/kg). At the high dose, saturated absorption was observed. Approximately 86% of the low dose and 1% of the high dose was absorbed in 168 hours, the majority of which occurred within 48 hours. For the difluorobenzene ring test article, urine was a major route of excretion in the low-dose group, but not in the high-dose group (<1%). Conversely, 93-102% of the high dose and 4-19% of the low dose was eliminated in feces. Elimination via expired air was insignificant. Biliary excretion using the aniline ring label showed that all the radioactivity in the feces of females and 40% of that in males are biliary excretion products. Although, the majority of both urinary and fecal excretion occurred within 48 hours, excretion by both routes was biphasic, with slower phase occurring throughout the post-exposure, resulting in accumulation in adipose tissue. This phenomenon was probably due to entero-hepatic circulation. Accumulation of radioactivity in muscle and adipose tissue 4 hours post dosing with 3.5 mg/kg benzyl label was 30% and 42%, respectively. At 168 hours post dose, these values were 6% and 19%, respectively, suggesting an accumulation in the adipose tissue. High doses of both labels resulted in negligible tissue burden (<0.3%) indicating saturation absorption.

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Metabolism / Metabolites
Metabolism proceeds via hydrolysis to a benzoic acid and aryloxyphenylurea and aryoxyaniline moieties.
The metabolic fate of flufenoxuron was determined using two radiolabeled positions (aniline and difluorobenzene ring). Flufenoxuron exhibited a dose-dependant absorption following a single low dose (3.5 mg/kg) or single high dose (350 mg/kg). ... For the flufenoxuron aniline ring test article, the parent and a total of 10 urinary metabolites accounted for approximately 5% of the administered dose, and were considered non-significant. Fecal excretion of metabolites was quantitatively greater with parent compound accounting for the greatest portion of radioactivity. However, most fecal metabolites represented < 1% of the administered dose. Both [4-(2-chloro, alpha,alpah,alpha-trifluoro-p-tolyoxy)-2-fluorophenyl urea] and [4- (2-chloro, alpha,alpah,alpha-trifluoro-p-tolyoxy)-2-fluoroaniline] were detected in the feces and urine following administration of the aniline ring labeled test article. Unextractable residues accounted for 7-8% of the dose. The major urinary metabolite of [14C- 2,6-difluorobenzene]flufenoxuron was the corresponding benzoic acid which, over 48 hours, accounted for 10-12% of the administered dose. Difluorobenzamide (<1%) was also detected in the urine along with unknown components all of which individually represented <1% of the dose. The only component detected in the feces of rats given the 2,6-difluorobenzene label was the parent compound. The results of the metabolism characterization studies with both label positions suggest that metabolism of flufenoxuron proceeds via hydrolysis to a benzoic acid metabolite, a phenyl urea metabolite ( 4-[2-chloro, alpha,alpah,alpha-trifluoro-p-tolyoxy]-2-fluorophenyl urea), an aniline metabolite (4-[2-chloro, alpha,alpah,alpha-trifluoro-p-tolyoxy]-2-fluoroaniline), and subsequently several minor components.

Non-Human Toxicity Values
LC50 Rat inhalation >5.1 mg/L/4 hr
LD50 Mouse dermal > 2 g/kg
LD50 Rat dermal >2 g/kg
LD50 Rat oral >3 g/kg
For more Non-Human Toxicity Values (Complete) data for Flufenoxuron (6 total), please visit the HSDB record page.

[1]. Toxic Effects of Flufenoxuron on Development and Vascular Formation During Zebrafish Embryogenesis. Aquat Toxicol. 2019 Nov;216:105307.

Flufenoxuron is a benzoylurea insecticide, a member of monochlorobenzenes, a member of (trifluoromethyl)benzenes, a member of monofluorobenzenes and a difluorobenzene. It has a role as a mite growth regulator. It is functionally related to a diphenyl ether.
Flufenoxuron is under investigation in clinical trial NCT00922870 (Evaluation of Hemodynamic Effects of Cascade Hemofiltration in Septic Shock).

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Mechanism of Action
Flufenoxuron is a benzoylurea type acaricide/insecticide which inhibits chitin biosynthesis (MOA Group 15) in nymphal mites and caterpillars.

C21H11CLF6N2O3

488.77

488.036

101463-69-8

91766

Off-white to light yellow solid powder

1.5±0.1 g/cm3

169-172 °C (decomposes)

1.574

5.6

2

9

4

33

689

0

RYLHNOVXKPXDIP-UHFFFAOYSA-N

InChI=1S/C21H11ClF6N2O3/c22-12-8-10(21(26,27)28)4-7-17(12)33-11-5-6-16(15(25)9-11)29-20(32)30-19(31)18-13(23)2-1-3-14(18)24/h1-9H,(H2,29,30,31,32)

N-[[4-[2-chloro-4-(trifluoromethyl)phenoxy]-2-fluorophenyl]carbamoyl]-2,6-difluorobenzamide

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: This product requires protection from light (avoid light exposure) during transportation and storage.

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

DMSO: 250 mg/mL (511.49 mM)

Solubility in Formulation 1: ≥ 2.08 mg/mL (4.26 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% 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 20.8 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: ≥ 2.08 mg/mL (4.26 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 20.8 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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