ABSTRACT
AIM: To establish an LC-MS/MS method for determination of evodiamine concentration in rat plasma and to study its pharmacokinetic profile in rats. METHODS: Six rats were administrated (i.g.) evodiamine at the dose of 100 mg/kg. Blood samples were collected from eye socket. Evodiamine concentration in rat plasma was determined by LC-MS/MS method. The pharmacokinetic parameters were calculated using DAS program. RESULTS: A good linear relationship was obtained in the concentration range (0.2-50.0 ng/mL) studied (r2=0.9997). Average recoveries ranged from 96.12% to 99.46%. Intra-and inter-day relative standard deviations were 4.61%-13.51% and 5.65%-11.49%, respectively. The main pharmacokinetic parameters of evodiamine were as follows: Cmax (5.3±1.5) ng/mL; tmax (22±8) min; t1/2 (451±176) min. CONCLUSION: A selective and sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for the quantification of evodiamine in rat plasma is developed and validated. This method is successfully applied for the pharmacokinetic studies of evodiamine in rats.
ABSTRACT
AIM: To determine the concentration of escitalopram in human plasma by HPLC-MS/MS and investigate the pharmacokinetics of escitalopram. METH-ODS: The method involved protein precipitation with methanol. The chromatographic separation was achieved within 6.0 min by using methanol-water with 15 mmol·L-1 ammonium acetate-formic acid (72:28:O.1, v/v/v) as mobile phase and a Lichrospher CN 150 mm×4.6 mm analytical column. The analytes were detected using an electrospray ionization tandem mass spectrometry in SRM mode. Detection of the ions was performed by monitoring the transitions of m/z 325.0 to 234.0 for escitalopram and m/z 409.1 to 238.1 for amlodipine (intemal standard), respectively. RESULTS:The standard curve was linear ( r = 0. 999) over the concentration range of 0.20 - 50.00 ng· ml- 1. Accuracy and precision were below the acceptance limits of 15%. The recoveries of escitalopram ranged from 96.0% to 103.6%. The lower limit of quantification for escitalopram was 0.20 ng· ml-1 using 200 μl plasma sample.The pharmacokinetic parameters of escitalopram after a single oral dosing of escitalopram oxalate tablet (10 rog)to ten healthy male volunteers were achieved. The Cmax, Tmax, AUC0-t, AUC0-∞, t1/2 and Ke of escitalopram were 9.21±2.10 ng·ml-1 , 3.75±1.04 h, 514.6±152.3 ng·h·ml-1 ,540.5±162.3 ng·h·ml-1 , 34.06±7.71 h and 0.021±0.004 h-1,respectively. CONCLUSION:The determination of concentration of escitalopram in human plasma by HPLC-MS/MS method was repid, sensitive and reliable. It can be used for clinical pharmacokinetic study of escitalopram.
ABSTRACT
Objective: To study the technological parameters of the purification process of total saponins of Rubus parvifolius L. with macroreticular resin. Methods: The adsorptive characteristics and elutive parameters of the process were studied by taking the elutive and purified ratio of total saponins of Rubus parvifolius L. as marker. Results: 19.3mL of the extractive of total saponins of Rubus parvifolius L. was purified with a column of macroreticular resin (R1cm?H20cm,dried weight 2.68g) and was washed with 100mL of distilled water, then was eluted with 100mL of 50% ethanol. Conclusion: With macroreticular resin to adsorb and purify, the elutive ratio of total saponins of Rubus parvifolius L. was over 79.2% and the purity reached 55.3%. So this process of applying macroreticular resin to adsorb and purify total saponins of Rubus parvifolius L. is feasible.