Methyprylon (INN) and its salts
Methyprylon (INN) and its salts is listed in Annex II as a prohibited substance for cosmetic products placed on the EU market.
Chemical identity and properties
- IUPAC name
- 3,3-diethyl-5-methylpiperidine-2,4-dione
- Molecular formula
- C10H17NO2
- Molecular weight
- 183.25 g/mol
- Exact mass
- 183.125928785 Da
- XLogP3
- 0.8
- Topological polar surface area
- 46.2 Ų
- Hydrogen-bond donors
- 1
- Hydrogen-bond acceptors
- 2
- Covalent units
- 1
- Defined stereocentres
- 0
Also known as
16 more reported names
External database identifiers
- ChEBI:CHEBI:31837
- ChEMBL:CHEMBL1200790
- EPA DTXSID:DTXSID7023306
- PubMed:2866242
- PubMed:1686463
- PubMed:16792
Evidence from additional scientific databases
NIH PubChem PUG-View
Attributed physical-property, hazard, environmental and use annotations.
- Color/Form: CRYSTALS Source: Hazardous Substances Data Bank (HSDB)
- Color/Form: NEARLY WHITE POWDER Source: Hazardous Substances Data Bank (HSDB)
- Dissociation Constants: PKA= 12.0 Source: Hazardous Substances Data Bank (HSDB)
- LogP: 0.78 Source: DrugBank
- LogP: 1.2 Source: Human Metabolome Database (HMDB)
- Melting Point: 74-77 °C Source: Hazardous Substances Data Bank (HSDB)
- Odor: SLIGHT CHARACTERISTIC ODOR Source: Hazardous Substances Data Bank (HSDB)
- Physical Description: Solid Source: Human Metabolome Database (HMDB)
- Solubility: 11500 mg/L Source: DrugBank
- Solubility: SOL IN BENZENE, CHLOROFORM Source: Hazardous Substances Data Bank (HSDB)
- Solubility: VERY SOL IN ETHER Source: Hazardous Substances Data Bank (HSDB)
- Solubility: Partially sol in water (7%); freely sol in organic solvents such as alcohol Source: Hazardous Substances Data Bank (HSDB)
- Solubility: 1.13e+01 g/L Source: Human Metabolome Database (HMDB)
- Carcinogen Classification: No indication of carcinogenicity to humans (not listed by IARC). Source: Toxin and Toxin Target Database (T3DB)
- Signal: Danger Source: European Chemicals Agency (ECHA)
- GHS Hazard Statements: H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]; H315 (97.4%): Causes skin irritation [Warning Skin corrosion/irritation]; H317 (97.4%): May cause an allergic skin reaction [Warning Sensitization, Skin]; H318 (97.4%): Causes serious eye damage [Danger Serious eye damage/eye irritation]; H335 (97.4%): May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation] Source: European Chemicals Agency (ECHA)
- Precautionary Statement Codes: P261, P264, P264+P265, P270, P271, P272, P280, P301+P317, P302+P352, P304+P340, P305+P354+P338, P317, P319, P321, P330, P332+P317, P333+P317, P362+P364, P403+P233, P405, and P501 (click each P-code to see the statement) Source: European Chemicals Agency (ECHA)
- ECHA C&L Notifications Summary: Aggregated GHS information provided per 39 reports by companies from 2 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.; Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website. Source: European Chemicals Agency (ECHA)
- Health Effects: They cause slurred speech, disorientation and "drunken" behavior. They are physically and psychologically addictive. Source: Toxin and Toxin Target Database (T3DB)
- Toxicity Summary: Methyprylon binds at a distinct binding site associated with a Cl- ionopore at the GABAA receptor, increasing the duration of time for which the Cl- ionopore is open. The post-synaptic inhibitory effect of GABA in the thalamus is, therefore, prolonged. Source: Toxin and Toxin Target Database (T3DB)
- Uses: MEDICATION Source: Hazardous Substances Data Bank (HSDB)
- Uses: For the treatment of insomnia. Source: Toxin and Toxin Target Database (T3DB)
Mapped by: Existing checksum-valid CAS to unique PubChem CID match. Retrieved: 2026-08-31. Open source record
Scientific classifications and hazard annotations provide context and do not replace the market-specific regulatory decision shown above.
Additional source coverage and match status
| Source | Result | Checked |
|---|---|---|
| NIH PubChem PUG-View | Exact match | 2026-08-31 |
A recorded no-match is useful evidence that the source was checked; it is not a claim that the substance does not exist elsewhere.
Retrieved from NIH PubChem on 2026-08-31 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.
Record details
Chemical name
Methyprylon (INN) and its salts
Regulatory information
Key data
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What Annex II means for Methyprylon (INN) and its salts
Methyprylon (INN) and its salts is listed as a prohibited substance under Annex II of EU Cosmetics Regulation 1223/2009 and must not be intentionally added. Article 17 separately addresses unintended small quantities that are technically unavoidable under good manufacturing practice and compatible with the Article 3 safety requirement.
Formulators must screen their ingredients and raw materials to ensure none contain this substance. Suppliers should provide documentation confirming absence when requested.
The page also surfaces 12 related annex records with overlapping identifiers, annex logic or naming patterns.
Compliance checklist
- Verify this substance is absent from all raw materials and finished formulations.
- Request absence confirmation or CoA from raw material suppliers.
- Document the screening result in the Product Information File (PIF).
Frequently asked questions
Source note for Annex II record Methyprylon (INN) and its salts
This page summarizes one Annex II record for Methyprylon (INN) and its salts from public European Commission cosmetic materials and adds linked inventory or identifier matches when available.
Use this record page to review Annex II conditions for Methyprylon (INN) and its salts, but confirm any final regulatory decision against the current official annex wording and source files.
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