LC Analysis and Pharmacokinetic Study of Pachymic Acid After Intravenous Administration to Rats

Abstract

A simple and sensitive high-performance liquid chromatographic method with UV detection was developed and validated to investigate the concentration of pachymic acid (PA) in rat plasma. The sample preparation was a liquid-liquid extraction and chromatographic separation was achieved with a Dikma DiamonsilTM C18 column (250 × 4.6 mm I.D.) with a C18 guard column (8 × 4 mm I.D.) using a mobile phase consisting of MeOH-MeCN-aq. 0.45% H3PO4 (45:40:22) at a flow rate of 1.0 mL min−1. The UV detection was at 210 nm. Standard curves were linear (r = 0.9998) in plasma over the concentration range of 0.5–50 μg mL−1 and had acceptable accuracy and precision. Intra- and inter-day precisions expressed as the relative standard deviation (RSD) were 0.26–1.60% and 1.24–2.31%. The lower limit of quantification and lower limit of detection were 0.45 and 0.17 μg mL−1. The method has been used successfully to study the pharmacokinetics of PA. After a dose of 30 mg kg−1 by intravenous administration, the main pharmacokinetic parameters t 1/2, AUC0-∞, CL, Vss and MRT0-∞ were 8.79 ± 6.80 h, 18.90 ± 9.39 μg h mL−1, 0.53 ± 0.28 L h−1, 5.60 ± 4.60 L and 12.58 ± 9.95 h, respectively.