Buprenorphine

Buprenorphine	Last updated: 06/09/2025
(Also known as: probuphenine; RX-6029-M)

GENERAL INFORMATION

Description

An opioid analgesic agent for a variety of animals

Examples of veterinary uses

Used for pain relief or is used as a preanesthetic in a veterinary hospital or clinic setting

Examples of species treated

Horses; Hedgehogs; Sheep; Dogs; Cats

Approval status

VMR 2013/2033 approval status (GB/UK)

Approved - usually supplied as a prescription only medicine to be authorised by a veterinarian (POM-V)

EU Regulatory approval status

Approved

Chemical structure

Isomerism

Buprenorphine exhibits stereoisomerism, specifically chiral isomerism, due to multiple stereocentres in its complex polycyclic structure. It belongs to the morphinan class of opioids, and its molecular framework includes several fused rings and asymmetric carbon atoms, which give rise to distinct three-dimensional arrangements. The active form of buprenorphine is the (−)-enantiomer, which is responsible for its pharmacological effects as a partial agonist at the μ-opioid receptor and an antagonist at the κ-opioid receptor. This stereoisomer binds with high affinity and slow dissociation, contributing to its long duration of action and reduced risk of respiratory depression compared to full agonists. The stereochemistry is critical: other stereoisomers of buprenorphine do not exhibit the same receptor binding profile or therapeutic efficacy.

Chemical formula

C₂₉H₄₁NO₄

Canonical SMILES

CC(C)(C)C(C)(C1CC23CCC1(C4C25CCN(C3CC6=C5C(=C(C=C6)O)O4)CC7CC7)OC)O

Isomeric SMILES

C[C@]([C@H]1C[C@@]23CC[C@@]1([C@H]4[C@@]25CCN([C@@H]3CC6=C5C(=C(C=C6)O)O4)CC7CC7)OC)(C(C)(C)C)O

International Chemical Identifier key (InChIKey)

RMRJXGBAOAMLHD-IHFGGWKQSA-N

International Chemical Identifier (InChI)

InChI=1S/C29H41NO4/c1-25(2,3)26(4,32)20-15-27-10-11-29(20,33-5)24-28(27)12-13-30(16-17-6-7-17)21(27)14-18-8-9-19(31)23(34-24)22(18)28/h8-9,17,20-21,24,31-32H,6-7,10-16H2,1-5H3/t20-,21-,24-,26+,27-,28+,29-/m1/s1

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
buprenorphine	-

General status

Veterinary substance type

Analgesic, Medicinal drug

Substance groups

Opioid

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

Acts as an epsilon-opioid antagonist

Molecular targets

[Mu-type opioid receptor, partial agonist], [Kappa-type opioid receptor, Antagonist], [Delta-type opioid receptor, Antagonist]

CAS RN

52485-79-7

EC number

257-950-6

CIPAC number

US EPA chemical code

PubChem CID

644073

Therapeutic Class

Nervous system: Analgesics

ATCvet Code

QN02AE01

Controlled Drug?

UK: Class C, Schedule 3; EU: UN71, Class IV

Regulation 37/2010 MRL Classification

Molecular mass

467.65

PIN (Preferred Identification Name)

IUPAC name

(2S)-2-[(-)-(5R,6R,7R,14S)-9α-cyclopropylmethyl-4,5-epoxy-6,14-ethano-3-hydroxy-6-methoxymorphinan-7-yl]-3,3-dimethylbutan-2-ol

CAS name

17-(cyclopropylmethyl)-α-(1,1-dimethylethyl)-4,5-epoxy-18,19-dihydro-3-hydroxy-6-methoxy-α-methyl-6,14-ethenomorphinan-7-methanol; Buprenex

Forever chemical

Other status information

Relevant Environmental Water Quality Standards

Physical state

White crystalline powder

Commercial

Property

Product

Manufacturer

Authorisation Route

Legal Class (GB/UK)

Availability status

Current

Introduction & key dates

1965, patented; 1981, first medical approvals

Example products (past and present) using this active

Bupaq solution for injection

VetViva Richter GmbH

GB National authorisation

Prescription only medicine to be authorised by a veterinarian (POM-V)

Vetergesic, 0.3mg/ml solution for injection for Dog and Cats

Ceva Animal Health Ltd

UK National authorisation

Prescription only medicine to be authorised by a veterinarian (POM-V)

Bupredine multidose solution injection

Le Vet Beheer B.V.

GB National authorisation

Prescription only medicine to be authorised by a veterinarian (POM-V)

Buprevet Multidose Solution for injection

VetViva Richter GmbH

GB National authorisation

Prescription only medicine to be authorised by a veterinarian (POM-V)

Formulation and application details

Formulated as a solution for injection

Commercial production

Buprenorphine is produced through a semi-synthetic process starting from thebaine, a naturally occurring alkaloid found in opium. The synthesis involves a Diels–Alder reaction between thebaine and a dienophile to form a key intermediate, which is then alkylated using a Grignard reagent. This is followed by the formation of a cyanamide group, and subsequent deprotection steps to remove protective groups from the cyanamide and phenolic oxygen moieties, typically using alkali or alkaline earth sulphides. The final stages include derivatisation with a cyclopropyl halide and hydrogenation, yielding buprenorphine with its potent opioid receptor activity.

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)

0.636

Low

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

Melting point (°C)

209

Boiling point (°C)

Degradation point (°C)

Flashpoint (°C)

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

9.55 X 10⁰⁴

Calculated

Log P

4.98

High

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

Dissociation constant pKa) at 25 °C

8.31

at 25°C

Vapour pressure at 20 °C (mPa)

1.23 X 10^-08

Low volatility

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

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 soil and groundwater metabolites

None

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

norbuprenorphine
Note: Pharmacologically active

Human (Liver)

hydroxybuprenorphine

Human (Liver)

buprenorphine glucuronide

Human (Liver)

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 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)

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

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)

High (class III)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

243

Rat

Moderate

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

Mammals - Inhalation LC₅₀ (mg l⁻¹)

Other Mammal toxicity endpoints

Intraperitoneal LD₅₀ = 90 mg kg⁻¹

Mouse

Intravenous LD₅₀ = 197 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

Liver metabolism, excreted ~70 in bile and ~30% in urine

Health issues

Specific human health issues

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 cuase respiratory depression, decreased blood pressure and heart rate

Handling issues

Property

Value and interpretation

General

No information available

CLP classification 2013

Health: H302, H319, H332, H361, H373

WHO Classification

Not listed (Not listed)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

buprenorphine

French

German

Danish

Italian

Spanish

buprenorfina

Greek

Polish

Swedish

Hungarian

Dutch

Norwegian

Record last updated:	06/09/2025
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