Nystatin

Nystatin	Last updated: 11/09/2025
(Not known by any other names)

GENERAL INFORMATION

Description

A human and veterinary medicine used to treat fungal infections such as yeasts and moulds.

Examples of veterinary uses

Mainly used to treat oral (such as Candidiasis) or gastrointestinal tract infections

Examples of species treated

Cats; Dogs; Pet birds (budgerigars, lovebirds, finches, parrotlets, and cockatiels); Reptiles

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

Nystatin exhibits isomerism through the formation of interconvertible structural isomers (known as Peak 1 and Peak 2), the formation being highly influenced by pH. It is commercially prepared as Peak 1 but under some conditions may transition to Peak 2. This isomerisation is reversible, with a typical equilibrium ratio of approx. 55:45 (Peak 1 to Peak 2). Importantly, these isomers show distinct antifungal activity: Peak 1 is significantly more potent than Peak 2.

Chemical formula

C₄₇H₇₅NO₁₇

Canonical SMILES

CC1C=CC=CCCC=CC=CC=CC=CC(CC2C(C(CC(O2)(CC(C(CCC(CC(CC(CC(=O)OC(C(C1O)C)C)O)O)O)O)O)O)O)C(=O)O)OC3C(C(C(C(O3)C)O)N)O

Isomeric SMILES

C[C@H]1/C=C/C=C/CC/C=C/C=C/C=C/C=C/C(CC2C(C(C[C@](O2)(CC(C(CCC(CC(CC(CC(=O)O[C@H]([C@@H]([C@@H]1O)C)C)O)O)O)O)O)O)O)C(=O)O)O[C@@H]3[C@H]([C@H]([C@@H]([C@H](O3)C)O)N)O

International Chemical Identifier key (InChIKey)

VQOXZBDYSJBXMA-RKEBNKJGSA-N

International Chemical Identifier (InChI)

InChI=1S/C47H75NO17/c1-27-17-15-13-11-9-7-5-6-8-10-12-14-16-18-34(64-46-44(58)41(48)43(57)30(4)63-46)24-38-40(45(59)60)37(54)26-47(61,65-38)25-36(53)35(52)20-19-31(49)21-32(50)22-33(51)23-39(55)62-29(3)28(2)42(27)56/h5-6,8,10-18,27-38,40-44,46,49-54,56-58,61H,7,9,19-26,48H2,1-4H3,(H,59,60)/b6-5+,10-8+,13-11+,14-12+,17-15+,18-16+/t27-,28-,29-,30+,31?,32?,33?,34?,35?,36?,37?,38?,40?,41-,42+,43+,44-,46+,47+/m0/s1

2D structure diagram/image available?

Yes

General status

Veterinary substance type

Medicinal drug: Antifungal

Substance groups

Bacterial origin

Minimum active substance purity

Known relevant impurities

Substance origin

Natural

Mode of action

Binds to ergosterol, a major component of the fungal cell membrane. As concentrations build pores in the membrane develop leading to K+ leakage, acidification and fungal cell death

Molecular targets

[Ergosterol, Binder]

CAS RN

1400-61-9

EC number

215-749-0

CIPAC number

US EPA chemical code

202800

PubChem CID

6433272

Therapeutic Class

Intestinal Antiinfectives - Antidiarrheals, intestinal antiinflammatory/antiinfective agents; Antifungals for topical use - Antifungals for dermatological use

ATCvet Code

QA07AA02; QD01AA01

Controlled Drug?

Regulation 37/2010 MRL Classification

Molecular mass

926.09

PIN (Preferred Identification Name)

(1S,3R,4R,7R,9R,11R,15S,16R,17R,18S,19E,21E, 25E,27E,29E,31E,33R,35S,36R,37S)-33-((3-amino-3,6-dideoxy-β-L-mannopyranosyl)oxy)-1, 3,4,7,9,11,17,37-octahydroxy-15, 16,18-trimethyl-13-oxo-14, 39-dioxabicyclo(33.3.1)nonatriaconta-19,21,25,27,29,31-hexaene-36-carboxylic acid

IUPAC name

CAS name

Forever chemical

Other status information

Relevant Environmental Water Quality Standards

Physical state

Commercial

Property

Value

Availability status

Current

Introduction & key dates

1950, first isolated from bacteria

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

Dechra Veterinary Products A/S

Example products using this active

Canaural Ear Drops Suspension

Formulation and application details

Current products are mainly formulated as ear drops

Commercial production

Nystatin is produced through a fermentation process using the actinomycete bacterium Streptomyces noursei, which naturally synthesises the antibiotic. The culture is grown in a nutrient-rich medium under controlled conditions, allowing the microorganism to produce nystatin as a secondary metabolite. After fermentation, the broth is filtered to separate the mycelial mass, and the active compound is extracted using organic solvents like methanol and butanol. The extract undergoes phase separation and centrifugation, followed by washing with saline and alcohol solutions to remove impurities. The crude product is then clarified, chilled, and precipitated, often using ethyl acetate, and finally dried with ether to yield purified nystatin.

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)

360

Moderate

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

Melting point (°C)

160

Boiling point (°C)

Degradation point (°C)

250

Flashpoint (°C)

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

1.58 X 10^-03

Calculated

Log P

-2.8

Low

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

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)

10000

Rat

Low

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)

55.0

Meleagris gallopavo NOEL

High

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)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

10000

Rat

Low

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

Mammals - Inhalation LC₅₀ (mg l⁻¹)

Other Mammal toxicity endpoints

Intraperitoneal LD₅₀ = 4.4 mg kg⁻¹

Mouse

Intravenous LD₅₀ = 3.0 mg kg⁻¹

Mouse

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

Mainly fecal elimination

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 diarrhoea & abdominal pain
Harmful if swallowed in high doses

Handling issues

Property

Value and interpretation

General

May be combustible in some formulations
Not compatible with strong oxidising agents
Will emit toxic fumes if heated to decomposition

CLP classification 2013

WHO Classification

Not listed (Not listed)

UN Number

Not regulated

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

nystatin

French

nystatine

German

Danish

Italian

Spanish

Nistatina

Greek

Polish

Swedish

Hungarian

Dutch

Norwegian

Record last updated:	11/09/2025
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