Talazoparib is an inhibitor of mammalian polyadenosine 5'-diphosphoribose polymerase (PARP) enzyme. The chemical name of talazoparib tosylate is (8S,9R)-5-Fluoro-8-(4-fluorophenyl)-9-(1-methyl-1H-1,2,4-triazol-5-yl)-2,7,8,9-tetrahydro-3H-pyrido[4,3,2-de]phthalazin-3-one 4-methylbenzenesulfonate (1:1). The chemical formula of talazoparib tosylate is C26H22F2N6O4S, and the relative molecular mass is 552.56 Daltons. The chemical structure of talazoparib tosylate is shown below:
Talazoparib tosylate is a white to yellow solid. TALZENNA capsules for oral use are available as a 0.25 mg hard hypromellose (HPMC) capsule that contains 0.363 mg talazoparib tosylate equivalent to 0.25 mg talazoparib free base or as a 1 mg HPMC capsule that contains 1.453 mg talazoparib tosylate equivalent to 1 mg talazoparib free base.
Inactive ingredients: silicified microcrystalline cellulose (sMCC). The white/ivory and white/light red opaque capsule shells contain HPMC, yellow iron oxide, red iron oxide and titanium dioxide; and the printing ink contains shellac, black iron oxide, potassium hydroxide, ammonium hydroxide, and propylene glycol.