NEXIUM (esomeprazole magnesium)
The active ingredient in NEXIUM (esomeprazole magnesium)
Delayed-Release Capsules is bis(5-methoxy-2-[(S)-[(4-methoxy-3,5-dimethyl-2-pyridinyl)methyl]sulfinyl]-1H-benzimidazole-1-yl)
magnesium trihydrate, a compound that inhibits gastric acid secretion.
Esomeprazole is the S-isomer of omeprazole, which is a mixture of the
S- and R- isomers.
Its empirical formula is (C17H18N3O3S)2Mg
3H2O with molecular weight of 767.2 as a trihydrate and 713.1
on an anhydrous basis.
The magnesium salt is a white to slightly colored crystalline powder.
It contains 3 moles of water of solvation and is slightly soluble in water.
The stability of esomeprazole magnesium is a function of pH; it rapidly
degrades in acidic media, but it has acceptable stability under alkaline
conditions. At pH 6.8 (buffer), the half-life of the magnesium salt is
about 19 hours at 25C and about 8 hours at 37C.
NEXIUM is supplied as Delayed-Release Capsules for oral administration.
Each delayed-release capsule contains 20 mg or 40 mg of esomeprazole (present
as 22.3 mg or 44.5 mg esomeprazole magnesium trihydrate) in the form of
enteric-coated pellets with the following inactive ingredients: glyceryl
monostearate 40-50, hydroxypropyl cellulose, hydroxypropyl methylcellulose,
magnesium stearate, methacrylic acid copolymer type C, polysorbate 80,
sugar spheres, talc, and triethyl citrate. The capsule shells have the
following inactive ingredients: gelatin, FD&C Blue #1, FD&C Red #40, D&C
Red #28, titanium dioxide, shellac, ethyl alcohol, isopropyl alcohol,
n-butyl alcohol, propylene glycol, sodium hydroxide, polyvinyl pyrrolidone,
and D&C Yellow #10.