Rizatriptan Benzoate is the benzoate salt of Rizatriptan, a selective serotonin receptor agonist belonging to the triptan class of antimigraine medicines. It is used as an active pharmaceutical ingredient in formulations intended for the acute treatment of migraine attacks, with or without aura.
Rizatriptan Benzoate has the molecular formula C₂₂H₂₅N₅O₂ and a molecular weight of 391.47 g/mol. Its CAS Registry Number is 145202-66-0, and its FDA UNII is WR978S7QHH.
The current USP-NF monograph defines Rizatriptan Benzoate as containing NLT 98.0% and NMT 102.0%, calculated on the anhydrous basis.
Rizatriptan Benzoate consists of Rizatriptan associated with benzoic acid in a defined salt form. The active moiety, Rizatriptan, is a serotonin 5-HT₁B/5-HT₁D receptor agonist.
The API is described as a white to off-white crystalline solid. FDA information reports that Rizatriptan Benzoate is soluble in water at approximately 42 mg/mL at 25°C, expressed as free base.
Its defined salt form, crystalline character and controlled impurity profile are important considerations for pharmaceutical manufacturing and formulation development.
| Property | Details |
|---|---|
| API Name | Rizatriptan Benzoate |
| CAS Number | 145202-66-0 |
| Molecular Formula | C₂₂H₂₅N₅O₂ |
| Molecular Weight | 391.47 g/mol |
| PubChem CID | 77997 |
| FDA UNII | WR978S7QHH |
| ChEBI ID | CHEBI:8875 |
| API Type | Synthetic small-molecule salt |
| Active Moiety | Rizatriptan |
| Pharmacological Class | Serotonin 5-HT₁B/5-HT₁D receptor agonist |
| Therapeutic Class | Antimigraine agent |
| Physical Form | White to off-white crystalline solid |
| USP Assay | 98.0–102.0%, anhydrous basis |
The chemical identity and molecular characteristics are supported by PubChem and the USP-NF monograph.
Rizatriptan Benzoate is primarily used in pharmaceutical formulations for the acute treatment of migraine attacks in adults and appropriate pediatric patients according to the approved product labeling.
Rizatriptan acts on serotonin receptors involved in migraine pathophysiology. FDA labeling identifies Rizatriptan Benzoate as a selective 5-HT₁B/5-HT₁D receptor agonist.
Pharmaceutical dosage forms containing Rizatriptan Benzoate include conventional oral tablets and orally disintegrating tablets.
Rizatriptan is a selective agonist of 5-HT₁B and 5-HT₁D receptors. Activation of these serotonin receptors produces constriction of certain intracranial blood vessels and inhibits trigeminal sensory neurotransmission.
Rizatriptan also reduces the release of pro-inflammatory neuropeptides involved in migraine signaling. Through these mechanisms, the active moiety helps interrupt the physiological processes associated with an acute migraine attack.
Rizatriptan Benzoate has an established USP-NF drug-substance monograph with numerical requirements for assay and inorganic impurities.
The USP assay requirement is 98.0–102.0% on the anhydrous basis. The monograph uses liquid chromatography for assay determination. Current USP information specifies a 4.6-mm × 25-cm, 5-µm L11 column, 40°C column temperature, 1.5 mL/min flow rate and 20 µL injection volume. System suitability includes a tailing factor of NMT 3.5 and assay-standard RSD of NMT 0.73%.
The USP monograph also specifies:
Rizatriptan Benzoate API manufacturing involves controlled synthesis of the Rizatriptan active moiety followed by formation and purification of the benzoate salt.
Manufacturing controls should address starting materials, reaction intermediates, process-related impurities, salt formation, crystallization and drying. The final material should undergo validated analytical testing to confirm identity, assay, organic purity, water content and inorganic residue.
Controlled crystallization is particularly relevant to maintaining consistent physical properties of the crystalline API.
Rizatriptan Benzoate is a white to off-white crystalline solid with a molecular weight of approximately 391.48 g/mol.
FDA labeling reports water solubility of approximately 42 mg/mL at 25°C when expressed as free-base equivalent.
A TCI reference specification reports a melting point of approximately 178–182°C, with a reference value around 180°C. This is useful physicochemical information but should not be represented as a universal pharmacopoeial release specification.
Rizatriptan Benzoate API should be packaged in suitable pharmaceutical-grade containers that protect the material from contamination, moisture and unsuitable environmental exposure.
The applicable API specification and stability data should determine final storage conditions. Pharmaceutical packaging should maintain product identity, integrity and batch traceability throughout storage and transportation.
Pharmaceutical-grade Rizatriptan Benzoate API can be supported with appropriate quality and regulatory documentation, including:
Rizatriptan Benzoate is a well-characterized pharmaceutical salt with an established USP-NF monograph. Its quality requires control of assay, organic impurities, water, residue on ignition and other applicable analytical attributes.
A quality-focused Rizatriptan Benzoate API manufacturer in India should maintain controlled synthesis and salt-formation processes together with validated chromatographic methods and consistent batch-release testing.
The USP-NF assay range of 98.0–102.0% on the anhydrous basis, together with specified impurity, water and residue-on-ignition requirements, provides an established benchmark for pharmaceutical-grade Rizatriptan Benzoate.
| 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 0.1% |
| Heavy Metals | NMT 10 ppm |
| Individual Impurity | NMT 0.10% |
| Total Impurities | NMT 0.3% |
| Water Content | NMT 0.5% |
| Melting Point | Approximately 178–182°C |