Oxetacaine, also known as Oxethazaine, is a potent local anesthetic API used primarily for topical and gastrointestinal applications. It is chemically classified as an amino-amide local anesthetic and is notable for maintaining significant unionized activity under strongly acidic conditions.
Oxetacaine is identified by the chemical name 2,2′-(2-hydroxyethylimino)bis[N-(α,α-dimethylphenethyl)-N-methylacetamide]. It has the molecular formula C28H41N3O3 and a molecular weight of 467.64 g/mol. FDA GSRS identifies oxetacaine under CAS 126-27-2 and UNII IP8QT76V17.
The current British Pharmacopoeia 2025 monograph specifies oxetacaine at 99.0% to 100.5%, calculated with reference to the dried substance. BP describes the material as a white or almost white powder, practically insoluble in water, freely soluble in methanol and soluble in ethyl acetate.
The chemical identity, formula, molecular weight and CAS number are supported by FDA GSRS and PubChem.
The BP 2025 monograph provides the principal quality-control requirements for pharmaceutical oxetacaine.
Oxetacaine produces local anesthetic activity by reducing the ability of sensory nerves to generate and propagate electrical signals.
Its pharmacological use is therefore associated with local reduction of pain and sensory irritation, particularly in gastrointestinal preparations. PubChem classifies oxethazaine as a potent surface analgesic/local anesthetic.
Oxetacaine API is used in pharmaceutical development for formulations requiring potent local anesthetic activity.
Applications include:
Oxetacaine is commonly used in combination formulations rather than as a conventional systemic analgesic.
Oxetacaine is a crystalline pharmaceutical substance with a characteristic basic amino-amide structure.
The BP 2025 monograph specifically describes oxetacaine as practically insoluble in water, freely soluble in methanol and soluble in ethyl acetate.
The BP identification test is based on infrared absorption spectroscopy.
The infrared absorption spectrum of the sample must correspond to the reference spectrum of Oxetacaine CRS (RS 254).
Japanese Pharmacopoeia additionally describes UV-visible and infrared identification procedures, with the sample spectrum compared against the appropriate reference spectrum.
The BP 2025 specification is:
99.0–100.5% of C28H41N3O3, calculated with reference to the dried substance.
The BP assay is performed by non-aqueous titration, using 0.1 M perchloric acid in anhydrous acetic acid with potentiometric endpoint determination. Each mL of 0.1 M perchloric acid corresponds to 46.76 mg of C28H41N3O3.
Therefore, for your CMS, the numerical assay range should be retained, but it should not be incorrectly described as an HPLC assay.
BP 2025 uses thin-layer chromatography (TLC) for related substances.
The specification includes:
The BP method uses silica gel 60 and a mobile phase consisting of ammonia, absolute ethanol and toluene.
The BP 2025 monograph specifies:
This is the appropriate moisture/volatile-content specification for the BP API entry.
The BP 2025 specification for sulfated ash is:
NMT 0.1%
This test provides a measure of inorganic residue remaining after controlled sulfation and ignition.
The BP 2025 monograph does not provide a separate numerical heavy-metals limit in the publicly reproduced monograph.
However, Japanese Pharmacopoeia provides a heavy-metals limit of NMT 10 ppm for oxethazaine.
For a CMS page specifically claiming BP compliance, I recommend keeping the Heavy Metals field as 10 ppm (JP) rather than falsely labeling it as a BP limit.
Japanese Pharmacopoeia also specifies chloride at:
NMT 0.011%
This is a useful additional quality-control parameter for an oxetacaine API specification, although it is not part of the BP 2025 numerical section reproduced above.
The BP melting-point specification is:
100–104°C
An independent chemical-property database reports approximately 104–105°C, which is consistent with the upper portion of the pharmacopoeial range. The BP range should be preferred for the CMS specification.
Oxetacaine has an established pharmacopoeial identity.
The BP 2025 monograph provides numerical requirements for:
The Japanese Pharmacopoeia additionally provides controls for:
This makes oxetacaine one of the products where a CMS can be populated with substantial numerical quality information rather than relying on generic API specifications.
Oxetacaine should be stored in tight containers under controlled pharmaceutical storage conditions.
Protection from excessive moisture, heat and inappropriate environmental exposure is recommended to maintain API quality and stability. Japanese Pharmacopoeia specifically states tight containers for oxethazaine.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 99.0–100.5 |
| Loss on Drying | NMT 0.5% |
| Residue on Ignition | NMT 0.1% |
| Heavy Metals | NMT 10 ppm |
| Individual Impurity | NMT 0.5% |
| Water Content | NMT 0.5% |
| Melting Point | 100–104°C |