Methoxyflurane is a halogenated ether inhalation anesthetic and analgesic compound. It is a clear, colorless liquid with a characteristic fruity odor. Methoxyflurane has historically been used as an inhalational anesthetic and is also used in some markets at low doses for short-term analgesia.
Methoxyflurane is a specialized inhalation anesthetic pharmaceutical API. Its quality is particularly important because it is a volatile liquid and is subject to specific pharmacopeial requirements for purity, acidity, water and nonvolatile residue.
The current USP monograph defines Methoxyflurane as containing NLT 99.9% and NMT 100.0% of C₃H₄Cl₂F₂O.
CAS Number: 76-38-0
Molecular Formula: C₃H₄Cl₂F₂O
Molecular Weight: 164.97 g/mol
IUPAC Name: 2,2-Dichloro-1,1-difluoro-1-methoxyethane
Drug Class: Halogenated Ether
Therapeutic Class: Inhalation Anesthetic / Analgesic
Therapeutic Area: Anesthesiology / Pain Management
Molecule Type: Synthetic Small Molecule
NIST reports a molecular weight of 164.966 g/mol, while the USP monograph uses 164.97.
Methoxyflurane produces CNS depression through effects on neuronal signaling associated with general anesthetic activity. At higher historical doses it produces anesthesia, while lower-dose inhalation has been used for analgesia.
Methoxyflurane is associated with:
Methoxyflurane is a clear, colorless liquid with a fruity odor. Its reported melting point is approximately −35°C, while its boiling point is approximately 105°C at atmospheric pressure.
The USP specifies a specific gravity of 1.420–1.425.
A controlled Methoxyflurane manufacturing process may include:
USP testing specifically includes:
The USP assay requirement is 99.9%–100.0%. Water is limited to NMT 0.1%, and nonvolatile residue must not exceed 1 mg from a 50 mL sample.
The USP specifies storage in tight, light-resistant containers and avoidance of excessive heat.
Methoxyflurane is relevant to research involving:
| Parameter | Specification |
|---|---|
| Appearance | White crystalline powder or crystals |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 99.9%–100.0% |
| Loss on Drying | NMT 1.0% |
| Residue on Ignition | NMT 0.2% |
| Heavy Metals | NMT 10 ppm |
| Individual Impurity | ≤ 0.5% |
| Total Impurities | ≤ 1.5% |
| Water Content | NMT 0.5% |