Aminophylline

Aminophylline	Last updated: 16/09/2025
(Also known as: aminophylline dihydrate; aminophylline hydrous)

GENERAL INFORMATION

Description

Aminophylline is a bronchodilator used to relax muscles in the bronchial tubes of the lungs. It is the ethylenediamine salt of theophylline.

Examples of veterinary uses

Used in veterinary medicine for animals suffering from asthma, bronchitis and chronic coughs

Examples of species treated

Dogs; Cats; Pigs; Horses; Cattle; Birds

Approval status

VMR 2013/2033 approval status (GB/UK)

Not approved

EU Regulatory approval status

Approved

Chemical structure

Isomerism

The main component of aminophylline theophyllin has structural analogs and related compounds that share similar properties.

Chemical formula

C₁₆H₂₄N₁₀O₄

Canonical SMILES

CN1C2=C(C(=O)N(C1=O)C)NC=N2.CN1C2=C(C(=O)N(C1=O)C)NC=N2.C(CN)N

Isomeric SMILES

International Chemical Identifier key (InChIKey)

FQPFAHBPWDRTLU-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/2C7H8N4O2.C2H8N2/c2*1-10-5-4(8-3-9-5)6(12)11(2)7(10)13;3-1-2-4/h2*3H,1-2H3,(H,8,9);1-4H2

2D structure diagram/image available?

Yes

General status

Veterinary substance type

Bronchodilator, Cardiotonic, Medicinal drug

Substance groups

Methylxanthine drug

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

Primary mode of action is as a bronchal smooth muscle relaxant

Molecular targets

[Phosphodiesterase type III and IV, Inhibitor], [Adenosine A2B receptor, Binder], [Adenosine, Blocker], [Histone deacetylase, Activator]

CAS RN

317-34-0

Alternative/old CAS RN

12767-26-9; 442519-87-1

EC number

206-264-5

CIPAC number

US EPA chemical code

PubChem CID

9433

Therapeutic Class

Drugs for obstructive airway diseases; Aminophylline and adrenergics

ATCvet Code

R03DA05

Controlled Drug?

Regulation 37/2010 MRL Classification

Molecular mass

420.43

PIN (Preferred Identification Name)

IUPAC name

1,3-dimethyl-7H-purine-2,6-dione; ethane-1,2-diamine

CAS name

theophylline compound with ethylenediamine (2:1)

Global Governance status: Listed (✓) under

UK Poisons List Order 1972	Rotterdam Convention	Montreal Protocol
XNo The Poisons List Order 1972	XNo Rotterdam Convention	XNo Montreal Protocol
Stockholm Convention	OSPAR	EU Water Framework Directive
XNo Stockholm Convention	XNo OSPAR	XNo EU Water Framework Directive

Relevant Environmental Water Quality Standards

Forever chemical

Other status information

Physical state

A white or yellowish coloured powder with a faint ammonia-like smell

Commercial

Property

Value

Availability status

Current

Introduction & key dates

1950s, first synthesised; 1990s, vet use adopted

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

Domes Pharma
France

Example products using this active

Antilaiteux Comprimes
Antilactis Biocanina

Formulation and application details

Usually administered orally or by injection

Commercial production

The production of aminophylline involves forming a complex salt between theophylline, a xanthine derivative, and ethylenediamine. The process typically begins by dissolving theophylline in a suitable solvent followed by the gradual addition of ethylenediamine under controlled temperature and pH conditions. The reaction mixture is stirred and allowed to react, forming a stable 2:1 molar adduct of theophylline and ethylenediamine. After completion, the solution is cooled, filtered, and washed to remove excess reagents and byproducts. The final product is then dried and formulated.

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 at pH 7 (mg l⁻¹)

50000

High

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

Melting point (°C)

269

Boiling point (°C)

Degradation point (°C)

Flashpoint (°C)

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

Log P

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

Environmental release

No significant issues identified or anticipated

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)

243

Rat

Moderate

Mammals - Short Term Oral NOAEL (mg kg⁻¹ bw d⁻¹)

Mammals - Long Term (Chronic) Oral NOAEL (mg kg⁻¹ bw d⁻¹)

Birds - Acute LD₅₀ (mg kg⁻¹)

Birds - Short term dietary LC₅₀ (mg kg⁻¹ bw d⁻¹)

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)

Beneficial insects (Butterflies)

Contact

Notes

Oral

Notes

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)

243

Rat

Moderate

Mammals - Short Term Oral NOAEL (mg kg⁻¹ bw d⁻¹)

Mammals - Long Term (Chronic) Oral NOAEL (mg kg⁻¹ bw d⁻¹)

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

176

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

Other Mammal toxicity endpoints

Intravenous LD₅₀ = 150 mg kg⁻¹ bw

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

Aminophylline is rapidly absorbed by the body and converted to theophylline. About 10% of a dose of theophylline is excreted unchanged in the urine.

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

No data found

Eye irritant

Phototoxicant

No data found

General human health issues

May cause headaches, nausea, vomiting and grastrointestinal disturbances

Handling issues

Property

Value and interpretation

General

IMDG Transport Hazard Class 6,1
Corrosive
Incompatible materials with strong oxidising agents
Toxic fumes of carbon dioxide, carbon monoxide, nitrogen oxides may be released on heating

CLP classification 2013

Health: H301, H315, H318

WHO Classification

UN Number

UN2811

Waste disposal & packaging

Packaging group III (minor danger)

Shelf-life, storage, stability and reactivity

Product is chemically stable under ambient conditions

TRANSLATIONS

Language

Name

English

aminophylline

French

German

Danish

Italian

Spanish

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

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