Oxantel API is a synthetic anthelmintic compound belonging to the tetrahydropyrimidine/styrenic anthelmintic class. It is structurally related to pyrantel and is primarily recognized for activity against gastrointestinal nematode parasites. PubChem identifies Oxantel under CAS No. 36531-26-7, with molecular formula C13H16N2O and molecular weight 216.28 g/mol. The preferred chemical name is 3-[(E)-2-(1-methyl-5,6-dihydro-4H-pyrimidin-2-yl)ethenyl]phenol.
Oxantel is most commonly encountered in pharmaceutical products as Oxantel Pamoate, also called Oxantel Embonate. FDA's Substance Registration System identifies Oxantel Pamoate as a 1:1 salt of oxantel and pamoic acid, with CAS No. 68813-55-8, molecular formula C36H32N2O7, and molecular weight 604.6 g/mol.
PubChem specifically describes Oxantel as an anthelmintic that targets parasitic acetylcholine receptors and identifies Oxantel Pamoate as its pamoate salt.
Oxantel has a relatively low molecular weight of 216.28 g/mol and the molecular formula C13H16N2O. Its structure contains a phenolic hydroxyl group, a substituted pyrimidine ring and an E-configured ethenyl linkage. PubChem's preferred IUPAC name explicitly specifies the E configuration.
Oxantel Pamoate is substantially larger because it combines one oxantel molecule with one pamoic-acid component. Its formula is represented as C23H16O6·C13H16N2O, equivalent to C36H32N2O7, with a molecular weight of 604.6 g/mol.
Oxantel is an anthelmintic compound with activity associated with nematode neuromuscular signaling. Its pharmacological action is linked to interaction with parasite nicotinic acetylcholine receptors, resulting in disruption of normal neuromuscular function in susceptible parasites. PubChem classifies the compound as an anthelmintic and notes its relationship to pyrantel.
Oxantel Pamoate is particularly relevant to veterinary pharmaceutical formulations and has been used in combination products with other anthelmintic agents. Its pamoate salt provides a distinct pharmaceutical substance with different molecular weight and chemical identity from the Oxantel free base.
For pharmaceutical and commercial documentation, it is important to determine whether the intended product is Oxantel free base or Oxantel Pamoate.
The FDA Global Substance Registration System identifies Oxantel Pamoate as UNII UPY1D732T0 and lists 68813-55-8 among its identifiers. FDA also identifies Oxantel Pamoate as Oxantel Embonate, CP-14445-16, and Telopar.
The pamoate form is therefore the more relevant identity when preparing documentation for formulations specifically based on oxantel pamoate. Using the free-base molecular weight of 216.28 g/mol for an Oxantel Pamoate product would result in incorrect CMS information.
Oxantel API can be relevant to:
For a pharmaceutical-grade Oxantel API, identity and purity should be established using appropriate validated analytical procedures. Depending on the applicable specification, analytical characterization can include chromatographic assay, spectroscopic identity testing, related-substance determination, water determination, residual-solvent testing and other applicable quality attributes.
Publicly accessible authoritative sources reviewed for this page establish the chemical identity and molecular characteristics of Oxantel and Oxantel Pamoate, but do not establish a single universal numerical API release specification covering assay, related substances, loss on drying, heavy metals and residual solvents. Therefore, those fields are marked N/A below rather than using an unsupported specification.
A commercial API technical package may include:
For CMS accuracy, the CAS number, salt form and molecular weight should always correspond to the exact material being offered.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |
| Loss on Drying | NMT 0.5% |
| Residue on Ignition | NMT 0.2% |
| Individual Impurity | ≤ 0.5% |
| Total Impurities | ≤ 1.5% |
| Water Content | NMT 0.5% |