Rupatadine Fumarate is a pharmaceutical active pharmaceutical ingredient belonging to the second-generation antihistamine class. It is the fumarate salt of rupatadine and is used in the manufacture of oral pharmaceutical formulations for the management of allergic conditions. Rupatadine has a dual pharmacological profile, acting primarily as a selective peripheral histamine H1-receptor antagonist while also exhibiting platelet-activating factor (PAF) antagonist activity. This combination makes Rupatadine Fumarate an important API for pharmaceutical products intended for allergic rhinitis and urticaria.
Rupatadine Fumarate has the molecular formula C₃₀H₃₀ClN₃O₄ and a molecular weight of 532.03 g/mol. Its primary CAS Number is 182349-12-8. The substance is a 1:1 fumarate salt consisting of rupatadine and fumaric acid. PubChem identifies Rupatadine Fumarate separately from the free-base form of Rupatadine.
The British Pharmacopoeia 2025, incorporating Ph. Eur. monograph 2888, describes Rupatadine Fumarate as a white or slightly pinkish powder. It is very slightly soluble in water, slightly soluble in anhydrous ethanol and very slightly soluble in heptane.
Rupatadine is a second-generation, long-acting antihistamine. Its principal pharmacological action is selective antagonism of peripheral H1 histamine receptors. It also has activity against platelet-activating factor receptors, providing a dual H1/PAF antagonistic profile.
For pharmaceutical API manufacturing, it is important to distinguish Rupatadine Fumarate from Rupatadine free base. Rupatadine free base has CAS 158876-82-5 and molecular weight approximately 416.0 g/mol, whereas the fumarate API has CAS 182349-12-8 and molecular weight 532.03 g/mol.
Rupatadine Fumarate is used in pharmaceutical formulations for the management of allergic conditions including allergic rhinitis and urticaria. Its antihistamine activity makes it suitable for oral pharmaceutical products developed to reduce symptoms associated with histamine-mediated allergic responses.
The API is relevant to manufacturers of antihistamine and anti-allergy formulations. Consistent control of chemical identity, assay, related substances, moisture and inorganic residue is important for maintaining raw-material quality and supporting reproducible finished-product manufacturing.
Rupatadine Fumarate is covered by Ph. Eur. monograph 2888. The BP 2025 monograph specifies a content of 98.0% to 100.5% on the dried substance. Identification is performed using infrared absorption spectrophotometry against Rupatadine Fumarate CRS.
The pharmacopoeial related-substances procedure uses liquid chromatography. The monograph controls specified impurities as well as unspecified impurities and total related substances. The specified limits include Impurity A NMT 0.15%, Impurity B NMT 0.5%, each unspecified impurity NMT 0.10%, and total impurities NMT 0.7%. The reporting threshold is 0.05%.
The monograph also specifies loss on drying NMT 0.5% and sulfated ash NMT 0.1%. These pharmacopoeial values provide more appropriate CMS specifications than generic commercial API limits.
Rupatadine Fumarate API is suitable for pharmaceutical formulation, development and commercial manufacturing applications. Appropriate analytical controls should be applied to identity, assay, related substances, loss on drying and sulfated ash according to the applicable pharmacopoeial or approved product specification.
Pharmaceutical documentation may include a Certificate of Analysis (CoA), specification sheet, Safety Data Sheet (SDS/MSDS), Certificate of Origin and applicable regulatory documentation, depending on customer and destination-market requirements.
Rupatadine Fumarate should be appropriately protected during storage. The BP/Ph. Eur. monograph specifies protection from light. Packaging should also provide appropriate protection against environmental exposure based on validated stability and packaging requirements.
Rupatadine Fumarate is an established antihistamine API with a defined European pharmacopoeial standard. Control of assay, related substances, loss on drying and sulfated ash supports consistent pharmaceutical raw-material quality and helps manufacturers maintain reproducible formulation performance.
| 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% |
| Individual Impurity | NMT 0.10% |
| Total Impurities | NMT 0.50% |