Study on impurities in domestic piroxicam gel
LI Jie
YUAN Song
ZHU Lei-jin
LIU Yang
Abstract：Objective:To study the impurities in domestic piroxicam gel.Methods:An HPLC method was established to study the impurities in piroxican gel.Waters XBridge C18(250 mm×4.6 mm,5 μm)column was used with gradient elution of mobile phase consisting of 0.5%of glacial acetic acid in water(adjust with ammonium hydroxide to a pH of 6.2)and acetonitrile.The flow rate was 1.0 mL·min-1,and the UV detection wavelength was 265 nm.Q-TOF technique was used to identify the structures of the main impurities in positive/negative ion modes with ESI as the ion resource.Results:Piroxicam peak was well separated from each impurity peak.A total of 4 major impurities(≥0.1%)were detected in 17 batches of domestic piroxicam gel:i.e.,2-hydroxy-benzoic acid 2-[bis(2-hydroxyethyl)amino]ethyl ester,2-hydroxypropyl-4-hydroxybenzoate,1-hydroxypropyl-2-yl-4-hydroxybenzoate,and 2-methyl-4-methoxy-N-(2-pyridyl)-2H-1,2-benzothiazin-3-formamide-1,1-dioxide,which were for the first time reported in piroxicam gel.Conclusion:The established HPLC method can be used for impurity detection of piroxicam gel.Impurities in domestic piroxicam gel mainly come from raw materials and excipient ethyl hydroxybenzoate.The production process should be optimized to improve the quality.
Keywords：piroxicam gelstudies on impuritiesethyl hydroxybenzoateHPLCQ-TOF
Publication Date：2026-05-15
Online Publishing Date：2026-08-14(First online date of this platform, not the publication date of the document)
Pages：9( 977-985 )