Liquid chromatographic determination including simultaneous "on-cartridge" separation of ranitidine cisapride drug combinations from paediatric plasma samples using an automated solid-phase extraction procedure

HPLC methodology was investigated for the simultaneous determination of cisapride and ranitidine in small volume paediatric plasma samples. Such a simultaneous determination proved difficult due to the small sample volumes, the low concentrations of the drugs and the different log P values of the two compounds. The two drugs and their respective internal standards were separated "on-cartridge" using HLB Solid Phase Extraction cartridges and the samples quantified by individual HPLC methodologies. The technique has been applied successfully to 60 paediatric plasma samples containing both cisapride and ranitidine. (C) 2004 Elsevier B.V. All rights reserved.