Development and Validation of a New Simple HPLC Method for the Determination of 3-[4-(2-Methylpropyl)phenyl] Propanoic Acid as an Impurity of Ibuprofen and Ibuprofen Sodium

摘要

Ibuprofen sodium is the sodium salts form of ibuprofen which exhibits better effects than standard ibuprofen as an analgesic by inhibiting the cyclooxygenase enzyme system. 3-[4-(2-Methylpropyl)phenyl] propanoic acid as one of potential impurities of ibuprofen was determined by a gas chromatography method after the methylation reaction according to the European Pharmacopoeia. Now, a new simple normal phase high-performance liquid chromatography (NP-HPLC) method has been established to separate 3-[4-(2-methylpropyl)phenyl]propanoic acid from ibuprofen sodium as well as from ibuprofen. Separation was performed on an Ultimate Silica column (250 mm x 4.6 mm, 5 mu m) using hexane, ethyl acetate and trifluoroacetate in the ratio (97:3:0.95, v/v/v) as mobile phase. The detection wavelength was performed at 264 nm. The NP-HPLC method could successfully separate 3-[4-(2-methylpropyl)phenyl]propanoic acid from the main peak within an analysis time of less than 20 min. Complementary of this work, a forced degradation study was carried out under specified conditions to investigate the chemical stability of ibuprofen sodium. The method was found to be precise, linear, accurate, sensitive, specific and robust according to the ICH guidelines.