Determination of 1,8-TMP rhein and its pharmacokinetics in rat plasma by HPLC / 中国药理学通报

ABSTRACT

Aim To develop a HPLC method for the determination of the concentration of 1,8-TMP rhein in rat plasma and study the pharmacokinetics of 1,8-TMP rhein in rat plasma after single dose i. v. administration of 1,8-TMP rhein (2, 4, 8 mg·kg - 1 ). Methods Emodin was used as an internal standard. Plasma sam-ples were extracted with methanol and analyzed by HPLC. The mobile phase was methanol - 0. 1% for-mic acid water (78 ∶ 22, V/ V), with a flow rate of 1. 0 mL·min - 1 and UV 275 nm as the detection wave-length. The plasma concentration of 1,8-TMP rhein in rats was determined by HPLC after single-dose intrave-nous injection in rats with 2,4 and 8 mg·kg - 1 of 1,8-TMP rhein, and the pharmacokinetic parameters were caclulated by DAS 2. 1. Results The result of cali-bration curve was linear over the range of 0. 05 ~ 10. 00 mg·L - 1 (r = 0. 996 2). The lower limit of quantifica-tion was 0. 05 mg · L - 1 . The intra-day and inter-day precision (RSD% ) were both lower than 6% , and the extraction recoveries were higher than 88% , respec-tively. The validated method was successfully applied to a pharmacokinetic study after i. v. administration of 1,8-TMP rhein in rats with a dose of 2,4 and 8 mg· kg - 1 . The T1 / 2 was (68. 35 ± 1. 36), (69. 32 ± 2. 1) and (69. 32 ± 2. 03) min, respectively. The AUC0 - t was ( 101. 03 ± 24. 90 ), ( 144. 79 ± 3. 29 ) and (231. 92 ± 19. 30 ) min · mg · L - 1 , respectively. Conclusion A simple and specific HPLC method for the analysis of 1,8-TMP rhein is successfully developed and applied to a pharmacokinetic study in rat plasma.