Naproxen Sodium

CAS Number 26159-34-2
Molecular Formula C14H13NaO3
Molecular Weight 252.245 g/mol
LogP 2.22
  • Naproxen sodium
  • Sodium (2S)-2-(6-methoxynaphthalen-2-yl)propanoate
  • 2-Naphthaleneacetic acid, 6-methoxy-alpha-methyl-, sodium salt, (alphaS)- (1:1)
  • 26159-34-2
  • Anaprox
  • EINECS 247-486-2
  • L-(-)-6-Methoxy-alpha-methyl-2-naphthaleneacetic acid sodium salt
  • Floginex
  • Gibixen
  • Leniartril
  • Synflex
  • Primeral
  • Naproxen natrium
  • Anapran
  • Anaprotab
  • Aprowell
  • Axer Alfa
  • Causalon Pro
  • Flogogin
  • Floneks
  • Floxalin
  • Gibinap
  • Karoksen
  • Miranax
  • Monarit
  • Naprodil
  • Naprodol
  • Naprovite
  • Naprux Gesic
  • Natrioxen
  • Pactens
  • Sodimax
  • Anaprox DS
  • Naprelan
  • UNII-9TN87S3A3C
  • Topcare all day pain relief
  • Sunprox
  • Sodium naproxen
  • (-)-Sodium (S)-6-methoxy-alpha-methyl-2-naphthaleneacetate


HPLC Separation of Acidic Drugs and Counter-Ions on Obelisc R Column

Mixed-mode columns allow to quantitate drugs and their counter-ions in one run. Hydrophobic acidic drug and hydrophilic inorganic counter-ions are separated and quantified on an Obelisc R HPLC trimodal column. This column can be used to quantify hydrophilic basic and hydrophilic acidic drugs, hydrophobic basic and hydrophobic acidic drugs, and corresponding organic and inorganic counter-ions. Various detection techniques can be applied to obtain reliable and robust method. Mixed-mode chromatography allows to retain ionizable compounds without ion-pairing reagent. This HPLC method can be adopted as universal and robust approach for analysis basic and acidic drugs and their counter-ions. Method is compatible with various detection techniques - ELSD, UV, CAD, and LC/MS.

Application Analytes:

Ibuprofen Sodium
Naproxen Sodium

USP Methods for the Analysis of Naproxen Using Legacy L1 Column
  Application Notes: Naproxen is a common NSAID used for pain relief and fever reducer. According to the USP methods, naproxen contains no less than 98% and no more than 101.5 percent naproxen calculated on a dried basis. The USP HPLC method for the separation of naproxen was developed on Legacy L1 column according to the US Pharmacopeia methodology. L1 classification is assigned to reversed-phase HPLC column containing C18 ligand. Support for the material is spherical silica gel with particles size 3-10 um and pore size of 100-120A. Resolution between critical pairs corresponds to rules and specifications of USP. Application Columns: Legacy L1 C18 HPLC column Application compounds: naproxen and benzophenone Mobile phase: water/MeCN/Glacial Acetic acid (49/50/1) Detection technique: UV Reference: USP35: NF30  


Column Legacy L1, 4.6x150 mm, 5 µm, 100A
Mobile Phase H2O/MeCN/Glacial Acetic acid (49/50/1)
Buffer Glacial Acetic acid
Flow Rate 1.0 ml/min
Detection UV, 254 nm


Class of Compounds Drug, Hydrophobic, Ionizable
Analyzing Compounds Naproxen, Benzophenone

Application Analytes:

Naproxen Sodium