AIM　To study the differences of the pharmacokinetics and tissue distribution of two enantiomers of nicardipine in the rabbit. METHODS　Biological samples were diluted by 1 mol*L-1 NaOH solution and extracted with n-hexane - ethyl acetate (1∶1). The concentrations of S-nicardipine and R-nicardipine in samples were determined by coupled achiral C18 column (150 mm×4.6 mm, 5 μm) and chiral OJ column (250 mm×4.6 mm, 10 μm) chromatography. RESULTS　The racemic nicardipine and the enantiomers in sample were separated well by the coupled system. The linear range was 55-550 ng*mL-1 for both enantiomers. The within-day and between-days RSD (n=5) were 5.25% and 8.97%, and the relative recoveries were 99.99% and 97.10% for R- and S- enantiomer, respectively. The mean Tmax, Cmax and AUC values were (2.49±0.03) h, (134±2) ng*mL-1 and (1082±32) ng*mL-1*h for S-nicardipine and (1.24±0.05) h, (109±2) ng*mL-1 and (778±22) ng*mL-1*h for R-nicardipine. The concentration of S-nicardipine were generally higher than that of R-nicardipine in main target tissues and cells. CONCLUSION There were significant differences between the two enantiomers of nicardipine in rabbit in pharmacokinetics and tissue distribution.

OBJECTIVE: To discuss the advantages and disadvantages of the non-price competition in Chinese hospital market and suggest some solutions. METHODS: Using the competition theory in health economics to analyze the situation in China and the advantages and disadvantages of the price competition as well as the causes accountable for the disadvantages. RESULTS & CONCLUSIONS: The government is suggested to understand the comparative (dis)advantages brought about by non-price competition and take possible solutions such as to clarify the role of market mechanism in regulating hospital performance, establish effective supervision system and referral system, and rationalize the income of physicians etc.

Objective To study the enantioselective characteristics and laws of ?-adrenoceptor antagonist isomers on Chiralcel ○R OD column. Methods The experiments were performed under the following HPLC conditions: a Chiralcel OD column (250 mm?4.6 mm, 10 ?m) as analytical column, a mixture of n-hexane/2-propanol/ triethylamine as the mobile phase, the fluorescence detection wavelengths at 275 nm (? ex) and 310 nm (? em), and the flow rate at 0.5 mL?min -1. The effect of interaction between stationary phase and 2-propanol or triethylamine concentration in mobile phase on the enantiomer resolution were investigated by the stoichiometric displacement model for retention. Results The lgI values of R-enantiomers of 3 out of 5 ?-adrenoceptor antagonist were higher than those of S-enantiomers. The 2-propanol in mobile phase would differently affect the resolution between enantiomers for each ?-adrenoceptor. With the increase of triethylamine concentration in mobile phase, the capacity factor (k′) of the enantiomers decreased but the resolution increased. Conclusion The lgI and Z values of SDM-R could be employed to characterize the resolution efficiency of Chiralcel OD column and the specific effect of enantiomers interacted with the stationary phase. Adding triethylamine in mobile phase will increase the resolution efficacy and changing column temperature can promote enantiomer resolution.

The development of pharmaceutical analytical methods represents one of the most significant aspects of drug development. Recent advances in microfabrication and microfluidics could provide new approaches for drug analysis, including drug screening, active testing and the study of metabolism. Microfluidic chip technologies, such as lab-on-a-chip technology, three-dimensional (3D) cell culture, organs-on-chip and droplet techniques, have all been developed rapidly. Microfluidic chips coupled with various kinds of detection techniques are suitable for the high-throughput screening, detection and mechanistic study of drugs. This review highlights the latest (2010–2018) microfluidic technology for drug analysis and dis-cusses the potential future development in this field.

A simple and rapid gas chromatography/mass spectrometry (GC/MS) analysis method was developed for the determination of fat-soluble parts of sinapis semina. Four major compounds were chosen as marker compounds to evaluate the method. Various extraction techniques were evaluated and the greatest efficiency was observed with sonication extraction using diethyl ether. The method was valuated as follows:acceptable apparatus suitability was obtained by testing the resolutions, tailing factors and theoretical plate number of the marker compounds; the precision and reproducibility, expressed as relative standard deviation (RSD), fell within the prescribed limits. Eight samples of sinapis semina collected from markets in Xi’an were monitored by using the method. The fingerprints of those samples were analyzed by hierarchical cluster analysis (HCA) similarity analysis. The result indicated that the combination of fingerprint and HCA could be used to analyze sinapis semina from different habitats.

It is very difficult to comprehensively achieve the quality control of traditional Chinese medicine (TCM), because some problems such as indicator simplification and lack of correlation between efficacy and indicator are ex-isted in the common quality control of TCM. Combined with the practical experience of our research work, this paper outlined the characteristics and applications of cell membrane chromatography (CMC) and discussed that CMC method can be used for quality control of TCM.

In China.traditional Chinese medicines (TCMs) have been used in clinical applications for thousands of years.The successful hyphenation of high-performance liquid chromatography (HPLC) and mass spectrometry (MS) has been applied widely in TCMs and biological samples analysis.Undoubtedly.HPLC/MS technique has facilitated the understanding of the treatment mechanism of TCMs.We reviewed more than 350 published papers within the last 5 years on HPLC/MS in the analysis of TCMs.The present review focused on the applications of HPLC/MS in the component analysis,metabolites analysis,and pharmacokinetics of TCMs etc.50% of the literature is related to the component analysis of TCMs,which show that this field is the most popular type of research.In the metabolites analysis,HPLC coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry has been demonstrated to be the powerful tool for the characterization of structural features and fragmentation behavior patterns.This paper presented a brief overview of the applications of HPLC/MS in the analysis of TCMs.HPLC/MS in the fingerprint analysis is reviewed elsewhere.

Objective To study the pharmacokinetics of tamoxifen at a high dosage, which will offer a theoretical support for an appropriate clinical use of the medicine in non-small cell lung cancer (NSCLC) patients. Methods Three qualified NSCLC patients are selected and given tamoxifen (TAM) 160 mg per Os. Blood samples were collected at different times and then analyzed by high-performance liguid chromatography. The PK-GRAPH program was used to obtain the parameters. Results The concentration-time courses of the TAM 160 mg were fitted to one-compartment model. The pharmacokinetic parameters were estimated as follows: Tmax (6.35±1.24)h, Cmax (217.39±7.71)ng/Ml, AUC (12 127.39±636.16)ng·h/Ml and T1/2ke (34.13±2.97)h. Conclusion TAM 160mg one day per Os cannot reach the effective maintenance concentration in vivo required for reversing MDR in vitro. Loading-maintenance dose strategy is recommended to study the pharmacodynamics of tamoxifen at a high dosage in NSCLC patients.

In recent years, cases of illegal addition of chemical substances into the TCMs and health-care products happened regularly. Therefore, it is particularly important to develop fast, sensitive and accurate analysis methods for detection of the adulterated chemical substances. Through literature survey of relevant papers published in 2016-2017, this article summarizes the application of various analytical techniques for adulterated chemical substances to the TCMs and health-care products with useful information for the further development of new methods and technologies in this field.

In this study,ecofriendly and economic carboxy-terminated plant fibers(PFs)were used as adsorbents for the effective in-syringe solid phase extraction(IS-SPE)of fluoroquinolone(FQ)residues from water.Based on the thermal esterification and etherification reaction of cellulose hydroxy with citric acid(CA)and sodium chloroacetate in aqueous solutions,carboxy groups grafted onto cotton,cattail,and corncob fibers were fabricated.Compared with carboxy-terminated corncob and cotton,CA-modified cattail with more carboxy groups showed excellent adsorption capacity for FQs.The modified cattail fibers were reproducible and reusable with relative standard deviations of 3.2％-4.2％within 10 cycles of adsorption-desorption.A good extraction efficiency of 71.3％-80.9％was achieved after optimizing the extraction condition.Based on carboxylated cattail,IS-SPE coupled with ultra-performance liquid chromatography with a photodiode array detector was conducted to analyze FQs in environmental water samples.High sensitivity with limit of detections of 0.08-0.25 μg/L and good accuracy with recoveries of 83.8％—111.7％were obtained.Overall,the simple and environment-friendly modified waste PFs have potential appli-cations in the effective extraction and detection of FQs in natural waters.