Determination and pharmacokinetical study of astragaloside IV in rats urine by HPLC-MS

AIM: The purpose is to develop a new method for the determination of Astragaloside IV in rat's urine. METHODS: The HPLC-MS method utilizing solid phase extraction was established to determine the concentration of Astragaloside IV in rat's urine. The analysis was carried on Diamonsil(tm) C ₁₈ column (4.6 X 250 mm, 5 μm). The mobile phase was CH ₃CN-H ₂O (40:60, v/v), with flow rate 0.8 ml/min, electrospray MS detector. RESULTS: The calibration curve was linear (r = 0.9991, n = 5) in the range of 0.1-10 μg/ml for Astragaloside IV. The limit of detection(LOD) was 10 ng/ml. The average recovery was 91.63% and RSD of intra-day and inter-day was smaller than 10%. This method was applied to the determination of ASI in rats and the pharmacokinetical parameters were calculated as follows: k = 0.27 h ^-1, ke = 2.5 × 10 ^-2h ^-1. CONCLUSION: A reliable HPLC- MS assay for Astragaloside IV. was developed. The assay method was appropriate for determination of Astragaloside IV in rat's urine.