Tetracycline

Tetracycline	Last updated: 15/09/2025
(Also known as: omegamycin ; abramycin ; anhydrotetracycline)

GENERAL INFORMATION

Description

Broad spectrum antibiotic compound synthesised or derived from certain microorganisms of the genus Streptomyces used in veterinary products and for aquaculture

Examples of veterinary uses

Used to treat certain bacterial infections and inflammatory skin conditions

Examples of species treated

Pigs; Chickens; Cattle; Poultry; Fish; Sheep

Approval status

VMR 2013/2033 approval status (GB/UK)

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

EU Regulatory approval status

Approved

Chemical structure

Isomerism

Tetracycline exhibits complex stereoisomerism due to its rigid, polycyclic structure and multiple chiral centres. The molecule contains four fused six-membered rings (A–D), with potential chirality at carbon atoms C-4, C-4a, C-5, C-5a, C-6, and C-12a, depending on substitution patterns. This leads to several stereoisomers, each with distinct spatial arrangements that can influence biological activity. Additionally, tetracycline undergoes tautomerism, particularly in the A-ring, where keto-enol equilibrium at positions C-1, C-2, and C-3 is essential for antibacterial function. Under acidic or basic conditions, structural rearrangements can occur, such as dehydration or lactonization, resulting in inactive forms like anhydrotetracycline or isotetracycline.

Chemical formula

C₂₂H₂₄N₂O₈

Canonical SMILES

CC1(C2CC3C(C(=O)C(=C(C3(C(=O)C2=C(C4=C1C=CC=C4O)O)O)O)C(=O)N)N(C)C)O

Isomeric SMILES

C[C@@]1([C@H]2C[C@H]3[C@@H](C(=O)C(=C([C@]3(C(=O)C2=C(C4=C1C=CC=C4O)O)O)O)C(=O)N)N(C)C)O

International Chemical Identifier key (InChIKey)

OFVLGDICTFRJMM-WESIUVDSSA-N

International Chemical Identifier (InChI)

InChI=1S/C22H24N2O8/c1-21(31)8-5-4-6-11(25)12(8)16(26)13-9(21)7-10-15(24(2)3)17(27)14(20(23)30)19(29)22(10,32)18(13)28/h4-6,9-10,15,25-26,29,31-32H,7H2,1-3H3,(H2,23,30)/t9-,10-,15-,21+,22-/m0/s1

2D structure diagram/image available?

Yes

General status

Veterinary substance type

Antimicrobial, Feed additive

Substance groups

Tetracycline substance

Minimum active substance purity

Known relevant impurities

Substance origin

Natural

Mode of action

Protein synthesis inhibitor

Molecular targets

[30S ribosomal protein S7, Antagonist], [30S ribosomal protein S14, Antagonist], [30S ribosomal protein S3, Antagonist], [30S ribosomal protein S8, Antagonist], [30S ribosomal protein S19, Antagonist], [16S rRNA, anatogonist], [Major prion protein, Antagonist]

CAS RN

60-54-8

EC number

200-481-9

CIPAC number

US EPA chemical code

PubChem CID

54675776

Therapeutic Class

Antiinfectants for systemic use; Dermatologicals; Genito urinary system & sex hormones; Sensory organs

ATCvet Code

QJ01AA07;QJ51AA07; QD06AA04; QG01AA90; QG51AA02; QS01AA09; QS02AA08; QS03AA02

Controlled Drug?

Regulation 37/2010 MRL Classification

Allowed substance (Table 1: All food producing species)

Molecular mass

444.4

PIN (Preferred Identification Name)

IUPAC name

(4S,4αS,5αS,6S,12αR)-4-(dimethylamino)-1,6,10,11,12α-pentahydroxy-6-methyl-3,12-dioxo-4,4α,5,5aα-tetrahydrotetracene-2-carboxamide

CAS name

6-methyl-1,11-dioxy-2-naphthacenecarboxamide

Forever chemical

Other status information

PAN Bad Actor chemical, Possible groundwater contaminant

Relevant Environmental Water Quality Standards

Physical state

Yellow crystalline solid

Commercial

Property

Value

Availability status

Current

Introduction & key dates

1953, introduced; 1960s, widely registered

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

Norbrook Laboratories Ltd
antiMedica GmbH
Eurovet Animal Health B.V.
Pharmaq Ltd

Example products using this active

Alamycin Solution for Injection
Animedazon Cutaneous Spray
Aquatet Premix Medicted Feedingstuff
Bovocycline Pessary IntrauterineTablet

Formulation and application details

Available in a wide range of formulations including solutions for injection, cutaneous sprays, pesseries and medicated feeding stuffs

Commercial production

Tetracycline is produced primarily through a microbial fermentation process using Streptomyces aureofaciens or Streptomyces rimosus. The production begins with inoculum development in a nutrient-rich medium containing carbohydrates (like sucrose and maltose), nitrogen sources (such as corn-steep liquor and soybean meal), and buffering agents like calcium carbonate to maintain pH stability. Once the culture is established, it undergoes submerged aerobic fermentation at controlled temperatures (28–30 DegC) and pH (6–6.5), with continuous aeration to optimise antibiotic biosynthesis. After fermentation, the broth is acidified and filtered to remove biomass, and tetracycline is extracted from the filtrate.

Impact on climate of production and use

As microbial-based products tend to use fermentation-based production processes rather than chemical synthesis, they typically have a lower fossil fuel input in formulation and active ingredient creation, and also have reduced downstream emissions due to biodegradability and minimal soil disruption, their life-cycle GHG emissions are expected to be low. Whilst hard and precise data is not available, broad estimates suggest that typically emissions are likely to be below 5 kg CO₂e/kg.

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

1700

High

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

Ethanol

Melting point (°C)

172.5

Boiling point (°C)

Degradation point (°C)

Flashpoint (°C)

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

5.01 X 10^-02

Calculated

Log P

-1.3

Low

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

Dissociation constant pKa) at 25 °C

3.3

pKa(2)=7.8; pKa(3)=9.6

Vapour pressure at 20 °C (mPa)

4.11 X 10^-18

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

Substance may enter the environment via the urine of treated animals or by leaching from spilt medicated feed.

Degradation

Property

Value

Source; quality score; and other information

Interpretation

Soil degradation (days) (aerobic)

DT₅₀ (typical)

Moderately persistent

DT₅₀ (lab at 20 °C)

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

Note

Manure DT₅₀ (days)

4.5

Aerated pig manure DT₅₀ 9 days non-aerated; Other data 9-17 days in liquid manure

Aqueous photolysis DT₅₀ (days) at pH 7

Value

0.1

Fast

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)

Non-mobile

K_oc (mL g⁻¹)

40000

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

-0.89

Calculated

Low leachability

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)

807

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)

260.5

Danio rerio 1 day

Low

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

29.4

Daphnia magna

Moderate

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) (EC₅₀)

1.0

Lemna gibba

Moderate

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

Algae - Acute (growth rate, fresh; mg l⁻¹) (EC₅₀)

2.2

Raphidocelis subcapitata

Moderate

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

Mesocosm study data

NOEAEC mg l⁻¹

Marine bivalves – Acute LC₅₀, mortality (mg l⁻¹)

> 520

Crassostrea gigas Larva

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)

807

Rat

Moderate

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

Mammals - Inhalation LC₅₀ (mg l⁻¹)

Other Mammal toxicity endpoints

Intraperitoneal LD₅₀ = 310 mg kg⁻¹

rat

Intravenous LD₅₀ = 129 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

Excreted unchanged in urine and to a lesser extent, in bile. Also identified in milk.

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 cause produce nausea, abdominal pain and burning and vomiting
May cause renal dysfunction or failure
Acts as co-carcinogen with UV radiation and increases the risk of skin cancer

Handling issues

Property

Value and interpretation

General

No information available

CLP classification 2013

WHO Classification

Not listed (Not listed)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

tetracycline

French

tetracycline

German

Danish

Italian

Spanish

tetraciclina

Greek

Polish

Swedish

Hungarian

Dutch

Norwegian

Record last updated:	15/09/2025
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