SPL Set ID: 1cd584de-b704-4d26-8451-e3247ffb8d08

Alvimopan capsules contain alvimopan, an opioid antagonist. Chemically, alvimopan is the single stereoisomer [[2(S)-[[4(R)-(3-hydroxyphenyl)-3(R), 4-dimethyl-1-piperidinyl]methyl]-1-oxo-3-phenylpropyl]amino]acetic acid dihydrate. It has the following structural formula: Alvimopan is a white to light beige powder with a molecular weight of 460.6, and the molecular formula is C 25 H 32 N 2 O 4 •2H 2 O. It has a solubility of <0.1 mg/mL in water or buffered solutions between pH 3.0 and 9.0, 1 to 5 mg/mL in buffered solutions at pH 1.2, and 10 to 25 mg/mL in aqueous 0.1 N sodium hydroxide. At physiological pH, alvimopan is zwitterionic, a property that contributes to its low solubility. Alvimopan capsules for oral administration contain 12 mg of alvimopan on an anhydrous basis suspended in the inactive ingredient polyethylene glycol. The capsule shell contains FD&C blue 1, FD&C red 3, gelatin, polyethylene glycol and titanium dioxide. The imprinting ink contains ammonia solution concentrated, black iron oxide, potassium hydroxide, propylene glycol and shellac. Alvimopan