Meloxicam

Meloxicam	Last updated: 12/09/2025
(Also known as: meloxicamum; metacam)

GENERAL INFORMATION

Description

A non-steroidal anti-inflammatory drug (NSAID) used for anti-inflammatory and analgesic purposes in veterinary care

Examples of veterinary uses

Generally used before surgery to control pain and inflammation after spays, neuters, and orthopedic surgeries

Examples of species treated

Dogs; Cats; Pigs; Cattle; Vultures

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

Meloxicam exhibits tautomeric isomerism, a type of isomerism where the molecule exists in dynamic equilibrium between structurally distinct forms due to the migration of a proton and a shift in bonding. In aqueous and mildly acidic environments, meloxicam can exist as a mixture of at least five neutral isomers, including enol, keto, zwitterionic, anion, and cationic forms2. These tautomers differ in the position of hydrogen atoms and the distribution of charges across the molecule, which affects its solubility, bioavailability, and interaction with biological targets. For instance, in neutral or slightly basic conditions, the anion form predominates, while in acidic media, the cationic and zwitterionic forms become more relevant.

Chemical formula

C₁₄H₁₃N₃O₄S₂

Canonical SMILES

CC1=CN=C(S1)NC(=O)C2=C(C3=CC=CC=C3S(=O)(=O)N2C)O

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

ZRVUJXDFFKFLMG-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C14H13N3O4S2/c1-8-7-15-14(22-8)16-13(19)11-12(18)9-5-3-4-6-10(9)23(20,21)17(11)2/h3-7,18H,1-2H3,(H,15,16,19)

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
meloxicam	-

General status

Veterinary substance type

Medicinal drug, Anti-inflammatory, Analgesic

Substance groups

Oxicam derivative

Minimum active substance purity

96%

Known relevant impurities

Substance origin

Synthetic

Mode of action

Inhibits prostaglandin synthesis thereby exerting an anti-inflammatory, analgesic, anti-exudative and antipyretic effect

Molecular targets

[Prostaglandin G/H synthase 2, Antagonist], [Prostaglandin G/H synthase 1, Antagonist]

CAS RN

71125-38-7

EC number

CIPAC number

US EPA chemical code

PubChem CID

Therapeutic Class

Musculo-skeletal system: Anti-inflammatory & antirheumatic products

ATCvet Code

QM01AC06

Controlled Drug?

Regulation 37/2010 MRL Classification

Allowed substance (Table 1: Bovine, Caprine, Porcine, Rabbit, Equidae)

Molecular mass

351.40

PIN (Preferred Identification Name)

IUPAC name

4-hydroxy-2-methyl-N-(5-methyl-2-thiazolyl)-2H-1,2-benzothiazine-3-carboxamide-1,1-dioxide

CAS name

2H-1,2-Benzothiazine-3-carboxamide, 4-hydroxy-2-methyl-N-(5-methylthiazolyl)-, 1,1-dioxide

Forever chemical

Other status information

Relevant Environmental Water Quality Standards

Physical state

Pale yellow powder

Commercial

Property

Value

Availability status

Current

Introduction & key dates

Circa 1995, introduced; 1998, first veterinary approval

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

aniMedica GmbH
Norbrook Laboratories Ltd
EU Pharmaceuticals Ltd

Example products using this active

Metacam
Animeloxan Oral Suspension
Chanoxidxyl Oral Suspension
Loxicom Oral Suspension
Metaxx Chewable Tablets

Formulation and application details

Often formulated as oral suspensions, tablets and solutions for injection

Commercial production

The production of meloxicam involves a multi-step chemical synthesis starting with key intermediates such as 4-hydroxy-2-methyl-N-(5-methyl-2-thiazolyl)benzenesulfonamide. The initial step typically includes the formation of the benzothiazine ring system through condensation and cyclization reactions. This is followed by sulfonation and methylation to introduce the necessary functional groups. A refined method uses montmorillonite K10 clay impregnated with ZnCl₂ as a heterogeneous catalyst, enabling a one-step synthesis with high yield and minimal environmental impact. After synthesis, the crude product undergoes purification via crystallisation and filtration to remove impurities and ensure pharmaceutical-grade quality.

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)

7.15

Low

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

Melting point (°C)

254

Boiling point (°C)

Degradation point (°C)

Flashpoint (°C)

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

2.69 X 10⁰³

Calculated

Log P

3.43

High

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

Dissociation constant pKa) at 25 °C

3.8

pka(2) = 7.6

Vapour pressure at 20 °C (mPa)

1.42 X 10^-10

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

No absorption >290 nm

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)

Slightly mobile

K_oc (mL g⁻¹)

1700

Notes and range

Estimated

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)

Low potential

CT₅₀ (days)

Not available

Known soil and groundwater metabolites

None

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

5'-carboxy meloxicam
Note: Pharmacologically inactive

Mammals (urine and faeces)

5'-hydroxymethyl meloxicam
Note: Pharmacologically inactive

Mammals (urine and faeces)

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 83.5

Rat

High

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)

High (class III)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 83.5

Rat

High

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

Mammals - Inhalation LC₅₀ (mg l⁻¹)

Other Mammal toxicity endpoints

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

Occupational exposure to meloxicam may occur through inhalation and dermal contact

Mammalian dose elimination route and rate

Almost completely metabolised and excreted as breakdown products in the urine and faeces. The mean elimination half-life (t1/2) ranges from 15 hours to 20 hours.

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 gastrointestinal toxicity and bleeding, tinnitus &/or headaches
Possible kidney, liver & blood toxicant
May cause dermatitis or other skin problems

Handling issues

Property

Value and interpretation

General

IMDG Transport Hazard Class 6.1

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

meloxicam

French

meloxicam

German

Danish

Italian

Spanish

meloxicam

Greek

Polish

Swedish

Hungarian

Dutch

Norwegian

Record last updated:	12/09/2025
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