Sunitinib is a kinase inhibitor present in SUTENT capsules as the malate salt. Sunitinib malate is described chemically as (2S)-2-hydroxybutanedoic acid with N-[2-(diethylamino)ethyl]-5-[(Z)-(5-fluoro-1,2-dihydro-2-oxo-3H-indol-3-ylidine)methyl]-2,4-dimethyl-1H-pyrrole-3-carboxamide (1:1). The molecular formula is C22H27FN4O2 ∙ C4H6O5 and the molecular weight is 532.6 Daltons. The chemical structure of sunitinib malate is:
Sunitinib malate is a yellow to orange powder with a pKa of 8.95. The solubility of sunitinib malate in aqueous media over the range pH 1.2 to pH 6.8 is in excess of 25 mg/mL. The log of the distribution coefficient (octanol/water) at pH 7 is 5.2.
SUTENT (sunitinib malate) capsules are supplied as printed hard shell capsules containing 12.5 mg, 25 mg, 37.5 mg or 50 mg of sunitinib (equivalent to 16.7 mg, 33.4 mg, 50.1 mg, or 66.8 mg of sunitinib malate, respectively). The capsules contain the following inactive ingredients: croscarmellose sodium, magnesium stearate, mannitol, and povidone (K-25). The orange gelatin capsule shells contain titanium dioxide and red iron oxide; the caramel gelatin capsule shells contain titanium dioxide, red iron oxide, yellow iron oxide, and black iron oxide; and the yellow gelatin capsule shells contain titanium dioxide and yellow iron oxide. The white printing ink contains shellac, propylene glycol, sodium hydroxide, povidone, and titanium dioxide and the black printing ink contains shellac, propylene glycol, potassium hydroxide, and black iron oxide.