Procaine hydrochoride

Procaine hydrochoride	Last updated: 08/09/2025
(Also known as: novacaine; procaine HCl; aminocaine; chlorocaine)

GENERAL INFORMATION

Description

The hydrochloride salt form of procaine, a benzoic acid derivative with local anesthetic and antiarrhythmic properties

Examples of veterinary uses

Used as a local anaesthetic for minor surgical procedures on a variety of animals

Examples of species treated

Cattle; Sheep; Goats, Horses; Pigs; Dogs; Cats

Approval status

VMR 2013/2033 approval status (GB/UK)

Approved - Legal class and so availability varies with product and application

EU Regulatory approval status

Approved

Chemical structure

Isomerism

None

Chemical formula

C₁₃H₃₀N₂O₂Cl

Canonical SMILES

CCN(CC)CCOC(=O)C1=CC=C(C=C1)N.Cl

Isomeric SMILES

International Chemical Identifier key (InChIKey)

HCBIBCJNVBAKAB-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C13H20N2O2.ClH/c1-3-15(4-2)9-10-17-13(16)11-5-7-12(14)8-6-11;/h5-8H,3-4,9-10,14H2,1-2H3;1H

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
Procaine	-

General status

Veterinary substance type

Anesthetic, Medicinal drug

Substance groups

Aminobenzoate

Minimum active substance purity

99%

Known relevant impurities

Substance origin

Synthetic

Mode of action

Sodium channel modulator.

Molecular targets

[Sodium channel protein type 10 subunit alpha, Antagonist], [Glutamate [NMDA] receptor subunit 3A, Antagonist], [5-hydroxytryptamine 3 receptor, Antagonist], [Sodium-dependent dopamine transporter, Antagonist], [Neuronal acetylcholine receptor subunit alpha-2, Antagonist]

CAS RN

51-05-8

EC number

200-077-2

CIPAC number

US EPA chemical code

PubChem CID

Therapeutic Class

Nervous system: Anaesthetic

ATCvet Code

QN01BA52

Controlled Drug?

Regulation 37/2010 MRL Classification

Allowed susbstance (Table 1: All food producing species)

Molecular mass

272.77

PIN (Preferred Identification Name)

IUPAC name

2-(diethylamino)ethyl 4-aminobenzoate hydrochloride

CAS name

2-(diethylamino) ethyl p-aminobenzoate monohydrochloride

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

White, hygroscopic crystalline powder

Related substances & organisms

procaine benzylpenicillin

Commercial

Property

Value

Availability status

Current

Introduction & key dates

1905, first synthesised

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

Norbook Laboratories Ltd
VetViva Richter GmbH
Alfasan Nederland B.V.

Example products using this active

Adrenacaine Solution for Injection
Procamidor Duo Solution for Injection
Willcain Solution

Formulation and application details

Usually supplied as a solution for subcutaneous injection

Commercial production

The production of procaine hydrochloride begins with the esterification of 4-aminobenzoic acid and 2-(diethylamino)ethanol, typically in the presence of an acid catalyst like sulphuric acid. This reaction yields procaine base, which is then converted into its hydrochloride salt by reacting with dilute hydrochloric acid.

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)

68100

High

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

Melting point (°C)

155

Boiling point (°C)

195

Degradation point (°C)

Flashpoint (°C)

195

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

1.45 X 10^-01

Calculated

Log P

-0.84

Low

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

Dissociation constant pKa) at 25 °C

8.05

Vapour pressure at 20 °C (mPa)

1.03 X 10^-04

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

Max @ 221nm & 290nm for acid

Surface tension (mN m⁻¹)

Refractive Index

1.5611

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

para-aminobenzoic acid
Note: More toxic than parent

PABA

Human (Plasma, hydrolysis)

diethylaminoethanol
Note: More toxic than parent

Human (Plasma, hydrolysis)

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

200

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)

Ptychocheilus spp. 24 hr

Moderate

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)

200

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)

Mammals - Inhalation LC₅₀ (mg l⁻¹)

Other Mammal toxicity endpoints

Subcutaneous LD₅₀ = 597 mg kg⁻¹

Rat

Intravenous LD₅₀ = 38 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

Majority is metabolised and the metabolised are rapidly (in minutes) excreted mostly 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

Respiratory tract irritant

Skin irritant

Skin sensitiser

No data found

Eye irritant

Phototoxicant

No data found

General human health issues

May cause cardiac and vasodilation effects
May cause serious allergic reactions
Harmful if swallowed

Handling issues

Property

Value and interpretation

General

When heated to decomposition it emits toxic fumes of nitroxides
IMDG Transport Hazard Class 6.1
Hygroscopic in air

CLP classification 2013

WHO Classification

Not listed (Not listed)

UN Number

UN2811

Waste disposal & packaging

Packaging Group III (minor danger)

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

procaine hydrochoride

French

German

Danish

Italian

Spanish

Greek

Polish

Swedish

Hungarian

Dutch

Norwegian

Record last updated:	08/09/2025
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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