Abstract:
OBJECTIVE To establish a rapid LC-MS method for the determination of chidamide in cerebrospinal fluid and plasma of SD rats, and apply it to the pharmacokinetic study of cerebrospinal fluid and plasma in rats after intravenous injection of chidamide.
METHODS The specificity, precision, accuracy, matrix effect and stability of the established LC-MS method for detecting the concentration of chidamide in cerebrospinal fluid and plasma of rats were investigated and verified. Twelve male SD rats were divided into 2 groups with 6 rats in each group. They were given 3, 6 mg·kg
-1 intravenously, respectively. Cerebrospinal fluid and plasma were collected at 0.083, 0.25, 0.5, 1, 1.5, 2, 3 h after administration. The concentrations of chidamide in cerebrospinal fluid and plasma of rats were determined by LC-MS method, and the pharmacokinetic parameters of AUC,
Cmax,
Tmax and
t1/2 in cerebrospinal fluid and plasma were fitted by DAS pharmacokinetic software, and the blood-brain barrier permeability was calculated.
RESULTS Methodological studies showed that the linear range of chidamide in rat cerebrospinal fluid was 0.2~64 ng·mL
-1(
r=0.999 0, lower limit of quantification was 0.2 ng·mL
-1), and the linear range of chidamide in plasma was 2~1 000 ng·mL
-1(
r=0.999 1, lower limit of quantification was 2 ng·mL
-1). Inter-day and intra-day variability and accuracy of chidamide in cerebrospinal fluid and plasma all met the requirements of methodological verification. Pharmacokinetic study of rats showed that the AUC
0-t in cerebrospinal fluid was 16.01, 32.09 ng
-1·mL
-1·h after intravenous administration of 3, 6 mg·kg
-1,
Cmax were 17.58, 28.37 ng·mL
-1,
t1/2 were 1.14, 1.23 h. The AUC,
Cmax of plasma were 2 570.11, 4 537.63 ng
-1·mL
-1 h, 4 366.54, 9 103.97 ng mL
-1,
t1/2were 0.83, 0.77 h, respectively. The average blood-brain barrier permeability of chidamide in the two groups was 0.62% and 0.72%, respectively.
CONCLUSION The study establishes a simple, rapid and sensitive method for the determination of chidamide concentration in cerebrospinal fluid and plasma of rats, and successfully applies to the pharmacokinetic study of rats. Intravenous administration of chidamide can effectively cross the blood-brain barrier and directly act on brain tumors.