Chemical Form

Fexofenadine hydrochloride, one of the active ingredients of Allegra. It's a histamine H1-receptor antagonist with the chemical name (±)-4-[1-hydroxy-4-[4-(hydroxydiphenylmethyl)-1-piperidinyl]-butyl]- , -dimethyl benzeneacetic acid hydrochloride.

Configuration of Fexofenadine hydrochloride

The molecular weight is 538.13 and the empirical formula is C32H39NO4oHCl. Fexofenadine hydrochloride is a white to off-white crystalline powder. It is freely soluble in methanol and ethanol, slightly soluble in chloroform and water, and insoluble in hexane. Fexofenadine hydrochloride is a race mate and exists as a zwitterion in aqueous media at physiological pH. Extended-Release Tablets for oral administration contain 60 mg fexofenadine hydrochloride for immediate-release and 120 mg pseudoephedrine hydrochloride for extended-release

Configuration of Pseudoephedrine hydrochloride

Pseudoephedrine hydrochloride, the other active ingredient of ALLEGRA-D, is an adrenergic (vasoconstrictor) agent with the chemical name [S-(R*,R*)]- -[1-(methylamino)ethyl]-benzenemethanol hydrochloride and the following chemical structure: The molecular weight is 201.70. The molecular formula is C10H15NOoHCl. Pseudoephedrine hydrochloride occurs as fine, white to off-white crystals or powder, having a faint characteristic odor. It is very soluble in water, freely soluble in alcohol, and sparingly soluble in chloroform.