SPL Set ID: ba7d9e82-9b13-4607-b2f9-25e575b8c73b

Each rectal suppository contains 12.5 mg or 25 mg promethazine hydrochloride. The inactive ingredients present are ascorbyl palmitate, colloidal silicon dioxide, glyceryl monostearate, hard fat, and white wax. Promethazine hydrochloride suppositories, USP are for rectal administration only. Promethazine hydrochloride is a racemic compound; the empirical formula is C 17 H 20 N 2 S•HCl and its molecular weight is 320.88. Promethazine hydrochloride, a phenothiazine derivative, is designated chemically as (±)-10-[2-(Dimethylamino)propyl] phenothiazine monohydrochloride with the following structural formula: Promethazine hydrochloride USP occurs as a white to faint yellowish, crystalline powder. It is very soluble in water, freely soluble in ethanol and in methanol, practically insoluble in ethyl acetate, diethyl ether and acetone. promethazine-structure