Description

S-Fexofenadine is the pharmacologically active enantiomer of fexofenadine, a potent and selective non-sedating histamine H1-receptor antagonist. This high-purity active pharmaceutical ingredient (API) is critical for developing advanced antihistamine formulations with enhanced efficacy and a superior safety profile. It is primarily utilized by pharmaceutical manufacturers and research institutions in the development and production of next-generation allergy and cold medications.

Application

• Pharmaceutical API: Core active ingredient in prescription and over-the-counter (OTC) non-drowsy antihistamine tablets, capsules, and oral suspensions.
• Allergy Medication: Formulated for the treatment of seasonal allergic rhinitis (hay fever) and chronic idiopathic urticaria (hives).
• Enantiopure Drug Development: Serves as a key chiral building block in research focused on stereoselective pharmacology to minimize side effects.
• Generic Drug Manufacturing: Essential for producing bioequivalent generic versions of leading antihistamine brands.
• Clinical Research: Used as a reference standard in pharmacokinetic, pharmacodynamic, and bioanalytical studies.
• Combination Therapies: Incorporated into fixed-dose combination drugs for comprehensive cold and allergy relief.

Basic Information

Product Name	S-Fexofenadine
CAS No.	139965-11-0
Molecular Formula	C32H39NO4
Molecular Weight	501.66 g/mol
Synonyms	(S)-Fexofenadine; (-)-Fexofenadine; (S)-Carboxyterfenadine; Allegra (S-enantiomer); MDL 16455A (S-form); Terfenadine Carboxylic Acid Metabolite (S-enantiomer); (S)-4-[1-Hydroxy-4-[4-(hydroxydiphenylmethyl)-1-piperidinyl]butyl]-α,α-dimethylbenzeneacetic acid
EINECS	Contact for details

Quality Control

Our S-Fexofenadine CAS NO 139965-11-0 is manufactured under strict quality management systems. Each batch undergoes comprehensive analytical testing, including chiral purity verification, to ensure compliance with pharmaceutical-grade standards. A detailed Certificate of Analysis (COA) providing specifications for identity, assay, enantiomeric excess, and related substances is provided with every shipment to guarantee traceability and consistency.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry place at controlled room temperature (15-25°C). This material is hygroscopic (moisture-sensitive) and must be kept in a dry environment to maintain stability and potency.

Specification

Item	Specification
Appearance	White to off-white crystalline powder
Identification (IR)	Conforms to reference standard
Identification (HPLC)	Retention time matches reference standard
Assay (HPLC)	98.0% - 102.0% (on anhydrous basis)
Enantiomeric Excess (Chiral HPLC)	≥ 99.0%
Water (Karl Fischer)	≤ 1.0%
Residue on Ignition	≤ 0.1%
Heavy Metals	≤ 20 ppm
Related Substances (HPLC)	Individual impurity ≤ 0.5%; Total impurities ≤ 1.5%

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