ec-naproxen - Medication Listings

NAPROXEN (naproxen) tablets, EC-NAPROXEN (naproxen) delayed-release tablets and NAPROXEN SODIUM (naproxen sodium) tablets are nonsteroidal anti-inflammatory drugs available as follows: NAPROXEN tablets are available as yellow tablets containing 500 mg of naproxen for oral administration. EC-NAPROXEN delayed-release tablets are available as enteric-coated white tablets containing 375 mg of naproxen or 500 mg of naproxen for oral administration. NAPROXEN SODIUM tablets are available as dark blue tablets containing 550 mg of naproxen sodium for oral administration. Naproxen is a propionic acid derivative related to the arylacetic acid group of nonsteroidal anti-inflammatory drugs. The chemical names for naproxen and naproxen sodium are (S)-6-methoxy-α-methyl-2-naphthaleneacetic acid and (S)-6-methoxy-α-methyl-2-naphthaleneacetic acid, sodium salt, respectively. Naproxen has a molecular weight of 230.26 and a molecular formula of C 14 H 14 O 3 . Naproxen sodium has a molecular weight of 252.23 and a molecular formula of C 14 H 14 NaO 3 . Naproxen and naproxen sodium have the following structures, respectively: Naproxen is an odorless, white to off-white crystalline substance. It is lipid-soluble, practically insoluble in water at low pH and freely soluble in water at high pH. The octanol/water partition coefficient of naproxen at pH 7.4 is 1.6 to 1.8. Naproxen sodium is a white to creamy white, crystalline solid, freely soluble in water at neutral pH. The inactive ingredients in NAPROXEN tablets include: croscarmellose sodium, iron oxides, povidone and magnesium stearate. The inactive ingredients in EC-NAPROXEN delayed release tablets include: croscarmellose sodium, povidone and magnesium stearate. The enteric coating dispersion contains methacrylic acid copolymer, talc, triethyl citrate, sodium hydroxide and purified water. The imprinting on the tablets is black ink. The dissolution of this enteric-coated naproxen tablet is pH dependent with rapid dissolution above pH 6. There is no dissolution below pH 4. The inactive ingredients in NAPROXEN SODIUM tablets include: magnesium stearate, microcrystalline cellulose, povidone and talc. The coating suspension may contain hydroxypropyl methylcellulose 2910, Opaspray K-1-4227, polyethylene glycol 8000 or Opadry YS-1-4216.