Objective: To explore pharmacokinetic characteristics of the new calcium sensitizer-M6 in rat plasma

and establish a fast

convenient and effective HPLC for determination of M6 in rat plasma. Method: Jugular vein haemospasia was adopted

M6 was injected by tail vein in rats

plasma concentration was determined by HPLC after 1

3

5

10

15

30 min and 1

2

4

6

8 h

mobile phase of 1% acetic acid solution-acetonitrile (85:15)

detection wavelength was set at 280 nm.Plasma concentration-time curve was drawn

and pharmacokinetic parameters were calculated by PKSolover software. Result: Linear range of M6 was 3.125-200 mg·L-1

the limit of quantitation was 0.6 mg·L-1

the intra-day

inter-day precision and stabilization were less than 10%

recovery of method was more than 85%.These main pharmacokinetic parameters of M6 were as followed:tmax of 1 min

Cmax of 6.67 mg·L-1

t1/2 of 21.36 min

MRT of 30.83 min

concentration-time curve showed double peaks. Conclusion: Results suggest that t1/2 of M6 is longer than t1/2 of its prototype drug-PPTA.This HPLC is sensitive

rapid and accurate

it can be empolyed to determine concentration of M6 in rat plasma.