Application of GC-EI-MS for the identification and investigation of positional isomer in primaquine, an antimalarial drug.
A major impurity associated with primaquine drug samples obtained from European Pharmacopoeia (EP) and other commercial sources was detected and identified using HPLC, photo diode array (PDA), LC-MS/MS and gas chromatograph-electron impact-mass spectrometer (GC-EI-MS). PDA and LC-ESI-MS/MS data provided an evidence for it being isomeric in nature. However, spectral data obtained from the newly developed GC-EI-MS method has been utilised for structural elucidation and found to be conclusive to characterize this impurity as positional isomer, i.e. 8-(4-amino-4-methylbutyl amino)-6 methoxyquinoline. The structure of this impurity has been confirmed by its synthesis. Precursor of primaquine was also investigated using GC-EI-MS. The data obtained confirmed the origin of isomeric impurity in precursor.
Dongre
Vaijanath G
VG
Department of Chemistry, University of Mumbai, Vidyanagari, Kalina, Santacruz (East), India. donggrevg@yahoo.com
Karmuse
Pravin P
PP
Nimbalkar
M M
MM
Singh
Dharmendra
D
Kumar
Ashok
A
D000962:Antimalarials / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy; D011319:Primaquine / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D000962:Antimalarials; D011319:Primaquine