Description

Leflunomide CAS NO 75706-12-6 is a synthetic isoxazole derivative and a disease-modifying antirheumatic drug (DMARD) with potent immunomodulatory and anti-inflammatory properties. Its primary value lies in its ability to selectively inhibit dihydroorotate dehydrogenase (DHODH), a key enzyme in the de novo pyrimidine synthesis pathway, thereby suppressing the proliferation of activated lymphocytes. This mechanism makes it a critical active pharmaceutical ingredient (API) for the formulation of oral medications used in the treatment of autoimmune conditions, most notably rheumatoid arthritis.

Application

• Pharmaceutical API: Primary use as the active ingredient in prescription medications for managing moderate to severe rheumatoid arthritis.
• Autoimmune Disease Treatment: Used in formulations targeting other autoimmune disorders, such as psoriatic arthritis, due to its immunomodulatory action.
• Research Chemical: Serves as a key reference standard and biochemical tool in immunological and pharmacological research to study T-cell proliferation and autoimmune disease mechanisms.
• Drug Development: Utilized in pre-clinical and clinical development stages for new therapeutic agents targeting DHODH or similar pathways.
• Generic Drug Manufacturing: A vital component for pharmaceutical companies producing generic versions of leflunomide-based therapies.

Basic Information

Product Name	Leflunomide
CAS No.	75706-12-6
Molecular Formula	C12H9F3N2O2
Molecular Weight	270.21 g/mol
Synonyms	HWA 486; SU-101; Arava (Brand Name); 5-Methyl-N-[4-(trifluoromethyl)phenyl]-4-isoxazolecarboxamide; α,α,α-Trifluoro-5-methyl-4-isoxazolecarboxy-4'-toluidide
EINECS	Contact for details

Quality Control

Our Leflunomide is manufactured under strict quality management systems. Each batch is tested to ensure it meets high-purity pharmacopeial standards, including identification, assay, and control of specified impurities. A comprehensive Certificate of Analysis (COA) is provided with each shipment, detailing results for parameters such as appearance, HPLC purity, related substances, residual solvents, and heavy metals. We can supply material compliant with various international pharmaceutical standards, including USP and EP monographs, upon request.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated place at controlled room temperature (15-25°C). This product is hygroscopic (moisture-sensitive); ensure the container is kept tightly sealed to prevent absorption of atmospheric moisture.

Specification

Item	Specification
Appearance	White to off-white crystalline powder
Identification (IR)	Conforms to reference spectrum
Identification (HPLC)	Retention time corresponds to reference standard
Assay (HPLC)	98.0% - 102.0% (on anhydrous basis)
Related Substances (HPLC)	Individual impurity: ≤ 0.5%; Total impurities: ≤ 1.5%
Water Content (KF)	≤ 0.5%
Residue on Ignition	≤ 0.1%
Heavy Metals	≤ 20 ppm

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.