SPL Set ID: 59ef406b-79db-4efd-b993-08b937ac682b

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 empirical 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 3350. The capsule shell contains FD&C Blue 1, gelatin, sodium lauryl sulfate, and titanium dioxide. The black ink contains ammonium hydroxide, ferrosoferric oxide, propylene glycol, and shellac. Chemical Structure