HPLC Method Determination of Isoliquiritin Apioside and Isoliquiritin in Rat Plasma for Application in Pharmacokinetic Study after an Oral Administration of Zhigancao Extract

Table 1

Intraday and interday precision and accuracy for QC samples.

Analyte	Spiked concentration	Measured concentration	Intraday (𝑛=6)		Measured concentration	Interday (𝑛=3)
	(μg/mL)	(μg/mL)	RSD (%)	RE (%)	(μg/mL)	RSD (%)	RE (%)
ILA	0.12	0.12 ± 0.01	6.2	−3.6	0.12 ± 0.01	9.0	0.4
	0.48	0.46 ± 0.02	5.6	−3.4	0.48 ± 0.03	7.0	−0.8
	3.07	3.08 ± 0.16	5.4	0.2	3.02 ± 0.16	4.8	0.7
IL	0.15	0.15 ± 0.01	5.9	1.4	0.15 ± 0.01	9.7	−2.3
	0.6	0.62 ± 0.03	6.8	3.1	0.61 ± 0.04	6.8	1.0
	3.84	3.78 ± 0.24	5.0	−1.7	3.73 ± 0.18	3.5	−2.7

(Inter-day) RSD =((∑^𝐼_𝑖=1∑^𝑛_𝑗=1(𝑋_𝑖𝑗−𝑋_..)²−𝑛∑^𝐼_𝑖=1(𝑋_𝑖.−𝑋_..)²)/(𝑁−𝐼)/𝑋_..)×100%, (Inter-day) RSD =(𝑛∑^𝐼_𝑖=1(𝑋_𝑖.−𝑋_..)²/(𝐼−1)/𝑋_..)×100%.