Ionic liquids as mobile phase additives for feasible assay of naphazoline in pharmaceutical formulation by HPTLC-UV-densitometric method.
A specific and reliable high-performance thin layer chromatography method with densitometry detection has been developed for the determination of naphazoline nitrate in nasal drops. The best separation of the basic analyte, without spot tailing, was achieved by using a mobile phase composed of acetonitrile-water (60:40, v/v), adding 1.5 % (v/v) imidazolium-class ionic liquid and covering the plates with a stationary phase based on RP-18 with F254S (10 × 20 cm). The presented results confirm that imidazolium tetrafluoroborate ionic liquids are efficient suppressors of free silanols, which are considered to be responsible for troublesome and irreproducible chromatographic determinations of basic compounds. The developed chromatographic system was found to be convenient in use and to provide a repeatable assay of naphazoline nitrate in nasal drops, which could not be obtained with the use of standard silanol suppressing mobile phase additives such as triethylamine or dimethyloctylamine.
Department of Medicinal Chemistry, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, Jurasza 2, 85-094 Bydgoszcz, Poland. mmars@cm.umk.pl
Michał Piotr
MP
Marszałł
Wiktor Dariusz
WD
Sroka
Aleksandra
A
Balinowska
Dominik
D
Mieszkowski
Marcin
M
Koba
Roman
R
Kaliszan
D000097:Acetonitriles / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002855:Chromatography, Thin Layer / Q000379:methods; D003720:Densitometry / Q000379:methods*; D007093:Imidazoles / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry*; D009278:Naphazoline / Q000032:analysis* / Q000737:chemistry; D019999:Pharmaceutical Solutions / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*
D000097:Acetonitriles; D007093:Imidazoles; D052578:Ionic Liquids; D019999:Pharmaceutical Solutions; D009278:Naphazoline; C032159:acetonitrile