ARTHROTEC is a combination product containing diclofenac sodium, a nonsteroidal anti-inflammatory drug (NSAID) with analgesic properties, and misoprostol, a gastrointestinal (GI) mucosal protective prostaglandin-1 (PGE1) analog. ARTHROTEC tablets are white to off-white, round, biconvex, and approximately 11 mm in diameter. Each tablet consists of an enteric-coated core containing 50 mg (ARTHROTEC 50) or 75 mg (ARTHROTEC 75) of diclofenac sodium (equivalent to 46.39 mg or 69.58 mg of diclofenac, respectively) surrounded by an outer mantle containing 200 mcg misoprostol.
Diclofenac sodium is a phenylacetic acid derivative that is a white to off-white, virtually odorless, crystalline powder. Diclofenac sodium is freely soluble in methanol, soluble in ethanol, and practically insoluble in chloroform and in dilute acid. Diclofenac sodium is sparingly soluble in water. Its chemical formula and name are:
C14H10Cl2NO2Na [M.W. = 318.14] 2-[(2,6-dichlorophenyl) amino] benzeneacetic acid, monosodium salt.
Misoprostol is a water-soluble, viscous liquid that contains approximately equal amounts of two diastereomers. Its chemical formula and name are:
C22H38O5 [M.W. = 382.54] (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-oate.
Inactive ingredients in ARTHROTEC include: colloidal silicon dioxide; crospovidone; hydrogenated castor oil; hypromellose; lactose; magnesium stearate; methacrylic acid copolymer; microcrystalline cellulose; povidone (polyvidone) K-30; sodium hydroxide; starch (corn); talc; triethyl citrate.