SPL Set ID: 29cda698-cfd4-43e1-b69e-884d08d8918a

The active ingredient in ondansetron tablets, USP is ondansetron hydrochloride as the dihydrate, the racemic form of ondansetron and a selective blocking agent of the serotonin 5-HT 3 receptor type. Chemically it is (±) 1, 2, 3, 9-tetrahydro-9-methyl-3-[(2-methyl-1H-imidazol-1-yl)methyl]-4H-carbazol-4-one, monohydrochloride, dihydrate. It has the following structural formula: The empirical formula is C 18 H 19 N 3 O∙HCl∙2H 2 O, representing a molecular weight of 365.9. Ondansetron HCl dihydrate is a white to off-white powder that is soluble in water and normal saline. Each 4-mg ondansetron tablet for oral administration contains ondansetron HCl USP dihydrate equivalent to 4 mg of ondansetron. Each 8-mg ondansetron tablet for oral administration contains ondansetron HCl USP dihydrate equivalent to 8 mg of ondansetron. Each 24-mg ondansetron tablet for oral administration contains ondansetron HCl USP dihydrate equivalent to 24 mg of ondansetron. Each tablet also contains the inactive ingredients lactose, magnesium stearate, microcrystalline cellulose, polyvinyl alcohol, polyethylene glycol, pregelatinized starch, talc and titanium dioxide. In addition, the 4 mg also contains yellow iron oxide and the 24 mg also contains FD&C blue #2 aluminum lake and iron oxide red. Chemical Structure