NAPRELAN®* Tablets contain naproxen sodium, a member of the arylacetic acid group of nonsteroidal anti-inflammatory drugs (NSAIDs). NAPRELAN® (naproxen sodium) Tablets use the proprietary IPDAS®** (Intestinal Protective Drug Absorption System) technology. It is a rapidly disintegrating tablet system combining an immediate release component and a sustained release component of microparticles that are widely dispersed, allowing absorption of the active ingredient throughout the gastrointestinal (GI) tract, maintaining blood levels over 24 hours. The chemical name for naproxen sodium is 2-naphthaleneacetic acid, 6-methoxy-a-methyl-sodium salt, (S)- with the following structural formula: