Chemically, trimethobenzamide hydrochloride is N-[p-[2-(dimethylamino)ethoxy]benzyl]-3,4,5-trimethoxybenzamide monohydrochloride. It has a molecular weight of 424.93 and the following structural formula:
Each 300-mg Tigan capsule for oral use contains 300 mg trimethobenzamide hydrochloride (equivalent to 274.3 mg of trimethobenzamide) as the active ingredient. The inactive ingredients are D&C Red No. 28, FD&C Blue No. 1, lactose, magnesium stearate, starch and titanium dioxide.