Separation and quantification of ropinirole and some impurities using capillary liquid chromatography.
Ropinirole, 4-[2-(dipropylamino)ethyl]-1,3-dihydro-2H-indol-2-one, is a potent anti-Parkinson's disease drug developed by SmithKline Beecham Pharmaceuticals. Capillary liquid chromatography (CLC) was used for the separation and quantification of ropinirole and its five related impurities, potentially formed during its synthesis. A simultaneous optimization of three mobile phase parameters, i.e., pH, buffer concentration and acetonitrile content was performed employing an experimental design approach which proved a powerful tool in method development. The retention factors of the investigated substances in different mobile phases were determined. Baseline resolution of the six substances on a C18 reversed stationary phase was attained using a mobile phase with an optimized composition [acetonitrile-8.7 mM 2-(N-morpholino)ethanesulfonic acid adjusted to pH 6.0 (55:45, v/v)]. It was shown that CLC, operated in the isocratic mode under the mobile phase flow-rate of 4 microl/min, can determine the level of these impurities, down to a level of 0.06% of the main component within 25 min.
Coufal
P
P
Department of Analytical Chemistry, Faculty of Science, Charles University, Prague, Czech Republic. pcoufal@mail.natur.cuni.c2
Stulík
K
K
Claessens
H A
HA
Hardy
M J
MJ
Webb
M
M
D000978:Antiparkinson Agents / Q000737:chemistry / Q000302:isolation & purification*; D002853:Chromatography, Liquid / Q000379:methods*; D004340:Drug Contamination; D006863:Hydrogen-Ion Concentration; D007211:Indoles / Q000737:chemistry / Q000302:isolation & purification*
D000978:Antiparkinson Agents; D007211:Indoles; C046649:ropinirole