ABSTRACT
Objective To establish the quality standard of Radix Toddaliae Asiaticae. Methods Thin layer chromatography ( TLC) and high performance liquid chromatography ( HPLC) were used to identify and determine chloride nitidine and toddalolactone in Radix Toddaliae Asiaticae. The moisture and total ash contents were detected according to the methods recorded in appendix of Chinese Pharmacopeia (2010 edition) . Results Toddalolactone and chloride nitidine were detectable by TLC, the spots were clear and the dissociation was good. The established HPLC method was simple and accurate. The linear ranges of toddalolactone and chloride nitidine in Radix Toddaliae Asiaticae were 2.84~42.6 μg/mL and 25.6~385 μg/mL, and their recovery rates were 99.2 % ( RSD=1.12%) and 100 % ( RSD=0.71%) , respectively. The content of moisture was in the range of 75.8~98.9 mg/g and that of total ash was in the range of 12.4~33.6 mg/g. Conclusion The developed method is specific and accurate, and can provide useful reference for establishing quality standard of Radix Toddaliae Asiaticae.
ABSTRACT
The paper is to report the study of pharmacokinetics of transdermal administered nicotine in the brain of freely moving rat by using microdialysis with stable labeled isotope as internal standard. The pharmacokinetic behavior of nicotine in Sprague Dawley rat brain was investigated after intranasal administration (3.75 mg). Brain fluid samples were collected by intracerebral microdialysis with DL-nicotine as internal standard. Concentrations of nicotine and DL-nicotine in the sample were measured by HPLC-MS/MS. Main pharmacokinetic parameters were calculated and analyzed by Das 2.0 pharmacokinetic software. The recovery of nicotine and the delivery of DL-nicotine were the same. The fate of absorption and distribution was two compartment model and the values of t1/2alpha was 170.31 min, t1/2beta was 263.30 min and the AUC(0-infinity) was 2.75 x 10(5) microg x L(-1) min separately. DL-nicotine can be used to calibrate the recovery of nicotine, and the new method of stable isotope microdialysis can be used to study the pharmacokinetics of freely moving rat. It will make sense for the treatment of addiction of tobacco and provide a new thought for the research of pharmacokinetics-pharmacodynamic combination.