Fexofenadine impurity B - 2-[3-[(1RS)-1-hydroxy-4-[4-(hydroxydiphenylmethyl)piperidin-1-yl]butyl]phenyl]-2-methylpropanoic acid

Fexofenadine impurity C - (1RS)-4-[4-(hydroxydiphenylmethyl)piperidin-1-yl]-1-[4-(1-methylethyl)phenyl]butan-1-ol

Filgrastim

Finasteride

Finasteride for peak identification

Flavoxate hydrochloride

Flavoxate impurity A - 3-methyl-4-oxo-2-phenyl-4H-1-benzopyran-8-carboxylic acid

Flavoxate impurity B - ethyl 3-methyl-4-oxo-2-phenyl-4H-1-benzopyran-8-carboxylate

Flecainide acetate

Flecainide for system suitability