A new approach to evaluate stability of amodiaquine and its metabolite in blood and plasma

Abstract

A stability study for amodiaquine (AQ) and desethylamodiaquine (AQm) in whole blood and plasma is reported. AQ, AQm and chloroquine (CQ) were simultaneously analysed and the ratios AQ/CQ and AQm/CQ were used to ensure correct interpretation of the stability results. CQ was stable in whole blood and plasma at all tested temperatures enabling it to be a stability marker in stability studies. Simultaneous analysis of compounds, of which at least one is already known to be stable, permits a within sample ratio to be used as a stability indicator. The new approach significantly reduced bias when compared to the traditional approach. AQ and AQm were stable in plasma at -86°C and -20°C for 35 days, at 4°C for 14 days and at 22°C for 1 day. AQ and AQm were stable in blood at -86°C and 4°C for 35 days, at -20°C and 22°C for 7 days and at 37°C for 1 day. © 2005 Elsevier B.V. All rights reserved.