Nalmefene is a synthetic opioid receptor antagonist active pharmaceutical ingredient (API) structurally related to naltrexone. It is a morphinan-derived compound that acts primarily by interacting with opioid receptors, particularly the μ-opioid receptor, and is used in pharmaceutical applications involving alcohol dependence and opioid receptor modulation.
Nalmefene is available as a pharmaceutical substance and has been developed in different salt forms for medicinal products, including nalmefene hydrochloride dihydrate.
Nalmefene is a well-characterized opioid antagonist pharmaceutical API used in the development and manufacture of medicines and in pharmaceutical research.
Important API quality attributes include identity, assay, related substances, water content, residual solvents, elemental impurities and other applicable pharmaceutical quality parameters.
CAS Number: 55096-26-9
Molecular Formula: C21H25NO3
Molecular Weight: 339.43 g/mol
Chemical Name: (4R,4aS,7aR,12bS)-3-methyl-2,3,4,4a,5,6,7,7a-octahydro-1H-4,12-methanobenzofuro[3,2-e]isoquinolin-7-ol
Drug Class: Opioid Antagonist
Therapeutic Class: Alcohol Dependence / Opioid Receptor Antagonist
Therapeutic Area: Addiction Medicine / CNS
Molecule Type: Synthetic Small Molecule
Nalmefene is an opioid receptor antagonist that binds to opioid receptors and modifies opioid-mediated signaling.
Its pharmacological activity includes:
Nalmefene's pharmacological profile is relevant to medicines intended to reduce alcohol consumption in appropriate patients.
Nalmefene API is relevant to:
Nalmefene is used in certain pharmaceutical products for the reduction of alcohol consumption in adults with alcohol dependence where the objective is to reduce alcohol consumption rather than achieve immediate abstinence.
The European medicinal product Selincro contains nalmefene hydrochloride dihydrate, equivalent to 18 mg of nalmefene, and is used as part of a psychosocial support programme in appropriately selected patients.
Therapeutic use should always follow the applicable regulatory approval, prescribing information and clinical guidelines.
Nalmefene API should be distinguished from its pharmaceutical salt forms.
Nalmefene refers to the free-base drug substance with molecular formula C21H25NO3 and molecular weight 339.43 g/mol.
Nalmefene hydrochloride dihydrate is a salt/hydrate form used in pharmaceutical formulations and has a different molecular composition and molecular weight.
This distinction is important when preparing CMS product information, specifications and chemical data.
Nalmefene is a synthetic morphinan derivative with structural similarity to naltrexone. Its molecular structure contains a morphinan-type ring system and a phenolic hydroxyl group.
Physical appearance, polymorphic form, particle-size characteristics and other solid-state properties should be controlled according to the applicable API specification and batch-specific Certificate of Analysis.
Nalmefene is structurally related to naltrexone but contains a modified N-substituent. Its chemical structure contributes to its opioid receptor antagonist activity.
The defined stereochemical configuration of Nalmefene is an important aspect of its chemical identity and should be appropriately controlled during API manufacturing and analytical testing.
Typical Nalmefene API quality-control testing may include:
The applicable numerical acceptance criteria should be taken from the current approved API specification, pharmacopoeial monograph or validated manufacturer's specification.
Assay testing is performed using an appropriately validated analytical method to determine the content of Nalmefene and ensure consistency between API batches.
Related-substance testing is important for controlling process-related impurities, degradation products and other organic impurities that may affect API quality.
Numerical assay and impurity limits should be confirmed against the specific current specification for the API form being manufactured.
Nalmefene API is relevant to pharmaceutical development involving opioid receptor antagonists, alcohol dependence therapies, CNS medicines and addiction-related drug development.
Its established pharmacological profile and relationship to other morphinan opioid antagonists make it an important compound for pharmaceutical research and formulation development.
Nalmefene API should be stored in a tightly closed container under controlled pharmaceutical storage conditions, with appropriate protection from moisture, excessive heat and direct light.
Final storage requirements should be established from validated stability studies and the applicable API specification.
For commercial pharmaceutical applications, Nalmefene should be manufactured and tested under applicable GMP requirements.
Identity, assay, related substances, residual solvents, water and other critical quality attributes should be evaluated using validated analytical methods.
Where a recognized pharmacopoeial standard or approved regulatory specification applies, the current applicable edition should be used for quality control and release testing.
Nalmefene is relevant to research involving:
| Parameter | Specification |
|---|---|
| Appearance | White crystalline powder or crystals |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |
| Loss on Drying | NMT 1.0% |
| Residue on Ignition | NMT 0.5% |
| Individual Impurity | NMT 0.5% |
| Total Impurities | NMT 1.0% |
| Water Content | NMT 1.0% |
| Melting Point | Approximately 204–207°C |