Naproxen is a nonsteroidal anti-inflammatory drug (NSAID) of the propionic acid class (the same class as ibuprofen) that relieves pain, fever, swelling, and stiffness. It is a nonselective COX inhibitor, usually sold as the sodium salt.

Naproxen is commonly used to reduce pain, fever, inflammation, and stiffness caused by conditions such as migraine, osteoarthritis, kidney stones, rheumatoid arthritis, psoriatic arthritis, gout, ankylosing spondylitis, menstrual cramps, tendinitis, and bursitis. It is also used to treat primary dysmenorrheal.

• Appearance: White to almost white crystalline powder
• Infrared absorption : The infrared absorption spectrum is concordant with the reference spectrum
• Ultraviolet absorption: Absorptivities at 272nm, calculated on the dried base, do not differ by more than 3%
• Specific rotation: -17.0°~ -15.3°
• Loss on drying: ≤1.0%
• Heavy metals: ≤0.002%
• Free Naproxen: ≤1.0%
• Impurity D( in house):≤0.10%
• Impurity E( in house, Impurity C in EP): ≤0.10%
• Any other impurity : ≤0.10%
• Total impurities: ≤1.0%
• Toluene:≤50ppm
• Methanol: ≤50ppm
• Hthanol:≤100ppm
• Assay( On the dried basis ): 98.0%~102.0%