Diamfenetide

Diamfenetide	Last updated: 16/09/2025
(Also known as: diamiphenethide; acemidophene)

GENERAL INFORMATION

Description

An anthelminitic substance used to control trematode and other flatworm infestations

Examples of veterinary uses

Liver fluke (Fasciola hepatica); Flatworms

Examples of species treated

Sheep; Cattle; Humans

Approval status

VMR 2013/2033 approval status (GB/UK)

Not approved

EU Regulatory approval status

Not approved

Chemical structure

Isomerism

Diamfenetide exhibits structural isomerism, particularly positional and conformational isomerism, due to its flexible ether-linked aromatic framework. The molecule contains two acetamide groups attached to para-substituted phenyl rings, which are connected via ethylenedioxy bridges. This arrangement allows for multiple conformers based on the rotation around the ether and amide bonds.

Chemical formula

C₂₀H₂₄N₂O₅

Canonical SMILES

CC(=O)NC1=CC=C(C=C1)OCCOCCOC2=CC=C(C=C2)NC(=O)C

Isomeric SMILES

International Chemical Identifier key (InChIKey)

JNEZCZPNQCQCFK-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C20H24N2O5/c1-15(23)21-17-3-7-19(8-4-17)26-13-11-25-12-14-27-20-9-5-18(6-10-20)22-16(2)24/h3-10H,11-14H2,1-2H3,(H,21,23)(H,22,24)

2D structure diagram/image available?

Yes

General status

Veterinary substance type

Anthelmintic; Antiparasitic

Substance groups

Benzamide derivative

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

Substance causing irreversible paralysis in flukes as well as affecting the fluke's metabolism, leading to an increase in glucose metabolism products and a decrease in ATP levels.

Molecular targets

[Metabolic interference and neuromuscular disruption]

CAS RN

36141-82-9

EC number

252-886-5

CIPAC number

US EPA chemical code

PubChem CID

37384

Therapeutic Class

Anthelmintics

ATCvet Code

None allocated

Controlled Drug?

Regulation 37/2010 MRL Classification

Molecular mass

372.4

PIN (Preferred Identification Name)

N,N′-{oxybis[(ethane-2,1-diyl)oxy-4,1-phenylene]}diacetamide

IUPAC name

4′,4‴-[oxybis(ethyleneoxy)]diacetanilide

CAS name

N,N′-[oxybis(2,1-ethanediyloxy-4,1-phenylene)]bis[acetamide]

Forever chemical

Other status information

Relevant Environmental Water Quality Standards

Physical state

Off-white coloured, odourless solid

Commercial

Property

Value

Availability status

Obsolete

Introduction & key dates

1970s, synthesised as a flukicide; 1980s, first vet use; 2013, not approved UK

Example manufacturers & suppliers of products using this active now or historically

Burroughs Wellcome & Co

Example products using this active

Coriban
Coryphamin

Formulation and application details

Was typically formulated as an oral suspension or drench

Commercial production

The production of diamfenetide involves a condensation reaction between beta,beta′-dichloroethyl ether and acetaminophen (paracetamol). First, diethylene glycol is reacted with thionyl chloride in the presence of pyridine to produce the dichloroethyl ether intermediate. This reactive ether is then coupled with two equivalents of acetaminophen under controlled conditions, forming the final bis-acetamide structure of diamfenetide. The reaction typically proceeds in an organic solvent such as ethanol or acetone, followed by purification through crystallisation.

Impact on climate of production and use

Published GHG data is not available for most pharmaceuticals. However, according to industry, global averages suggest producing 1 kg of a typical active pharmaceutical ingredient can range from 10 to 100 kg CO₂e for small molecule drugs and potentially up to 1000 kg CO₂e for complex biologicals such as vaccines, depending on the drug type, its formulation, complexity of synthesis, solvent recovery, and energy sources used.

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

Solubility - In water at 20 °C (mg l⁻¹)

Solubility - In organic solvents at 20 °C (mg l⁻¹)

Melting point (°C)

140

Boiling point (°C)

661.8

Degradation point (°C)

Flashpoint (°C)

354.1

Octanol-water partition coefficient at pH 7, 20 °C

1.66 X 10⁰³

Calculated

Log P

3.22

High

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

Henry's law constant at 25 °C (Pa m³ mol⁻¹)

Volatilisation as max % of applied dose lost

From plant surface

From soil surface

Maximum UV-vis absorption L mol⁻¹ cm⁻¹

Surface tension (mN m⁻¹)

Refractive Index

1.595

Environmental release

Degradation

Property

Value

Source; quality score; and other information

Interpretation

Soil degradation (days) (aerobic)

DT₅₀ (typical)

DT₅₀ (lab at 20 °C)

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

Note

Manure DT₅₀ (days)

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Note

Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7

Value

Note

Water-sediment DT₅₀ (days)

Water phase only DT₅₀ (days)

Sediment phase only DT₅₀ (days)

Air degradation

As this parameter is not normally measured directly, a surrogate measure is used: ‘Photochemical oxidative DT₅₀’. Where data is available, this can be found in the Fate Indices section below.

Decay in stored produce DT₅₀

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d (mL g⁻¹)

K_oc (mL g⁻¹)

Notes and range

Freundlich

K_f (mL g⁻¹)

K_foc (mL g⁻¹)

¹/_n

Notes and range

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

Bio-concentration factor

BCF (l kg⁻¹)

CT₅₀ (days)

Known metabolites

None

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 20000

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

(ppm diet)

Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)

Birds - Acute LD₅₀ (mg kg⁻¹)

Birds - Short term dietary (LC₅₀/LD₅₀)

Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)

Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹ dw soil)

Earthworms - Chronic NOEC, reproduction (mg kg⁻¹ dw soil)

Soil micro-organisms

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Non-target plants

Vegetative vigour ER₅₀ (g ha⁻¹)

Seedling emergence ER₅₀ (g ha⁻¹)

Honeybees (Apis spp.)

Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Unknown mode acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Chronic

Notes

Bumblebees (Bombus spp.)

Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Mason bees (Osmia spp.)

Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Other bee species (1)

Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)

Mode of exposure

Other bee species (2)

Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)

Mode of exposure

Beneficial insects (Ladybirds)

Beneficial insects (Lacewings)

Beneficial insects (Parasitic wasps)

Beneficial insects (Predatory mites)

Beneficial insects (Ground beetles)

Aquatic ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Temperate Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

Temperate Freshwater Fish - Chronic 21 day NOEC (mg l⁻¹)

Tropical Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

Temperate Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)

Temperate Freshwater Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)

Tropical Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)

Aquatic crustaceans - Acute 96 hour LC₅₀ (mg l⁻¹)

Sediment dwelling organisms - Acute 96 hour LC₅₀ (mg l⁻¹)

Sediment dwelling organisms - Chronic 28 day NOEC, static, water (mg l⁻¹)

Sediment dwelling organisms - Chronic 28 day NOEC, sediment (mg kg⁻¹)

Aquatic Plants (free-floating, fonds growth, fresh) - 7 day (mg l⁻¹)

Aquatic plants (rooted, growth rate, fresh) - 14 day (mg l⁻¹)

Algae - Acute (growth rate, fresh; mg l⁻¹)

Algae - Chronic (growth rate, fresh; mg l⁻¹)

Mesocosm study data

NOEAEC mg l⁻¹

Marine bivalves

HUMAN HEALTH AND PROTECTION

General

Property

Value

Source; quality score; and other information

Interpretation

Threshold of Toxicological Concern (Cramer Class)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 20000

Rat

Low

Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)

Mammals - Inhalation LC₅₀ (mg l⁻¹)

Other Mammal toxicity endpoints

Intraperitoneal LD₅₀ > 6300 mg kg⁻¹

Rat

ADI - Acceptable Daily Intake (mg kg⁻¹ bw day⁻¹)

ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)

AAOEL - Acute Acceptable Operator Exposure Level (mg kg⁻¹ bw day⁻¹)

AOEL - Acceptable Operator Exposure Level - Systemic (mg kg⁻¹ bw day⁻¹)

Dermal penetration studies (%)

Dangerous Substances Directive 76/464

Exposure Routes

Public

Occupational

Mammalian dose elimination route and rate

Eliminated via hepatic metabolism, followed by renal excretion of its active metabolite

Health issues

Specific human health issues (hazard-based)

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

No data found

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

No data found

Respiratory tract irritant

Skin irritant

Skin sensitiser

Eye irritant

Phototoxicant

No data found

General human health issues

No information available

Handling issues

Property

Value and interpretation

General

Will emit toxic gases if heated
Incompatible with strong oxidising agents

CLP classification 2013

Health: H315, H317, H319
Environment: H412

WHO Classification

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

Stable under ambient conditions

TRANSLATIONS

Language

Name

English

diamfenetide

French

German

Danish

Italian

diamfenetidium

Spanish

diamfenetida

Greek

Polish

Swedish

Hungarian

Dutch

Norwegian

Record last updated:	16/09/2025
Contact:	aeru@herts.ac.uk
Please cite as:	Lewis, K.A., Tzilivakis, J., Warner, D. and Green, A. (2016) An international database for pesticide risk assessments and management. Human and Ecological Risk Assessment: An International Journal, 22(4), 1050-1064. DOI: 10.1080/10807039.2015.1133242