Simultaneous determination of amodiaquine and pioglitazone on dried blood spots (DBS) by HPLC–DAD and its usefulness in pharmacokinetic studies.

A simple and rapid method for simultaneous determination of amodiaquine and pioglitazone in dried blood spots (DBS) was developed and validated. Blood samples were spotted on protein saver cards and dried and a 4-mm punch was extracted with methanol first and later with 1% acetic acid and dichloromethane. The separation was achieved on a C8 Zorbax Eclipse XDB analytical column (4 µm, 150 × 4.6 mm2i.d.) at 27°C with a mobile phase of methanol/0.2% acetic acid (60:40) at a flow rate of 0.8 mL/min and detected at 230 nm. The method was linear over the range 2–80 ng/mL for amodiaquine and 10–1500 ng/mL for pioglitazone with correlation coefficients greater than 0.9995. The limits of detection were 1.12 and 10.93 µg/L and the limits of quantification were 3.39 and 33.11 µg/L for amodiaquine and pioglitazone, respectively. The inter- and intra-day precision were <6.7 and <7% for amodiaquine and <6.3 and <3% for pioglitazone. The method was applied to estimate the pharmacokinetic (PK) parameters in four healthy volunteers and it was found to yield identical PK profiles with other earlier methods supporting the use of DBS as an alternative for PK study. [ABSTRACT FROM PUBLISHER]