Drug Metabolism in Drug Design and Development Basic Concepts and Practice

TABLE 10.3 Precision and accuracy of stop-flow HPLC/RFD for determining
relative radioactivity of muraglitazar and its metabolites in the incubation of [^14 C]
muraglitazar with UGT1A3.

Radioactivity peak 1 2

3 (muraglitazar

glucuronide)

4

(muraglitazar)

Precision
(N=5)

Stop-flow 2.60.3 4.70.6 12 0.6 70 1.4

LSC 2.30.5 5.10.6 13  272 1.5
Accuracy (%) 16 8.2 8.2 3.0

Stop flow LS/RFD (1 mL/min) was carried using the by-fraction mode (Fig. 10.11b) and counting
time was 1 min. LC–LSC was carried by counting HPLC fractions (four fractions per min) for
10 min by LSC.

FIGURE 10.12 Formation rates of muraglitazar glucuronide catalized by UGT1A3
determined by stop-flow HPLC–RFD (a) and HPLC–TopCount (b).

312 APPLICATIONS OF LIQUID RADIOCHROMATOGRAPHY TECHNIQUES