Simultaneous assessment of absorption and pharmacokinetic characteristics of four active flavonoids from Chimonanthus nitens Leaf Granules using LC-MS determination: and .

A sensitive UPLC-HRMS method was developed and validated for simultaneous quantification of four active flavonoids from Chimonanthus nitens Leaf Granules (CNLG) in biological matrix. The method was utilized in pharmacokinetic study of the four flavonoids in rats as well as other evaluation assays . It was revealed that rutin, nicotiflorin, and astragalin had poor oral bioavailability in rats possibly due to low intestinal permeability and metabolism in intestinal flora.

[Intestinal absorption components and absorption characteristics of Wuwei Qingzhuo San by everted intestinal sac models].

This study investigated the absorption profile of Wuwei Qingzhuo San in different intestinal segments and the absorption characteristics of its alkaloids(piperine, piperanine, piperlonguminine, and dihydropiperlonguminine). The everted gut sac model was established, and the chemical components of Wuwei Qingzhuo San in different intestinal segments were detected by UPLC-Q-TOF-MS. The content of piperine, piperanine, piperlonguminine, and dihydropiperlonguminine in intestinal absorption fluid was determined by UPLC-Q-TRAP-MS and the absorption parameters were calculated.

Effect of X-ray radiation on the pharmacokinetics of apatinib in rats.

The "radiotherapy-pharmacokinetic" ("RT-PK") phenomenon refers to the fact that radiation can significantly alter the pharmacokinetic behavior of a drug. At present, it is not clear whether there is an "RT-PK" phenomenon that can affect apatinib during concurrent chemoradiotherapy. In this study, we used a rat irradiation model to study the effects of X-ray radiation on absorption, tissue distribution, and excretion of apatinib.

[Identification of chemical constituents in Zhachong Shisanwei Pills by UPLC-Q-TOF-MS/MS].

Zhachong Shisanwei Pills, composed of 13 Chinese medicinal materials, are used for treating the diseases such as hemiplegia, pain of muscles and bones, rheumatism, and joint pain. The chemical composition and pharmacodynamics of Zhachong Shisanwei Pills have not been reported. Ultra-performance liquid chromatography/quadrupole-time-of-flight tandem mass spectrometry(UPLC-Q-TOF-MS/MS) was employed to quickly identify the chemical components of Zhachong Shisanwei Pills, which was performed with Shim-pack GIST C_(18) column(4.

[The in vitro inhibition and induction of cytochrome P450 activities by bentysrepinine: a novel candidate of anti-hepatitis B virus drug].

Bentysrepinine (Y101), a derivative of phenyalanine dipeptide, has a novel mechanism in the treatment of hepatitis B virus (HBV) infection with a good anti-HBV effect. In the present study, a fluorometric-based high throughput method using cytochrome P450 (CYP) screening kit was adopted to evaluate in vitro inhibition potential of Y101 on CYP isoenzymes by calculating remaining enzyme activities and inhibitory potential (IC(50) values) using the determined values of fluorescence intensity. The result showed that Y101 exhibited little activity in the inhibition of CYP1A2, CYP3A4, CYP2C9, CYP2C19 and CYP2D6 (IC(50) > 100 μmol·L(-1)).

[The in vitro transport mechanism of bentysrepinine: a novel anti-hepatitis B virus drug candidate].

Bentysrepinine (Y101), a derivative of phenylalanine dipeptide, is a novel drug candidate for the treatment of hepatitis B virus (HBV) infection. Our previous preclinical pharmacokinetic study showed that its in vivo absorption and distribution characteristics were probably related to transmembrane transport after Y101 was administered intragastically in rats. In this study, Caco-2 and MDCK-MDR1 cell models were used to investigate interactions between Y101 and P-gp through the apparent permeation coefficient (P(app)) and efflux ratio (RE); the results showed that Y101 was a substrate of P-gp.

Effects of Drug Transporters on Pharmacological Responses and Safety.

Recently, it is realized that transporters, apart from enzymes, play a key role in drug metabolism and pharmacokinetics. More and more pharmaceutical researchers focused on transporter study and found that drug transporters not only involved in pharmacokinetics including absorption, distribution, metabolism and excretion (ADME). but also in Drug-Drug interactions (DDIs).

[Determination of tamsulosin in dog plasma by a high sensitive liquid chromatography-tandem mass spectrometric method].

To develop and validate a liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for the determination of tamsulosin in dog plasma after oral administration of controlled-release tablet of tamsulosin hydrochloride, the samples and the internal standard, diphenhydramine, were extracted from dog plasma by n-hexane-dichloromethane (2 : 1), and separated on a Bonchrom XBP-C18 column using a mobile phase consisted of methanol-acetonitrile-ammonium formate (10 mmol x L(-1)) (30 : 40 : 30, v/v/v), at a flow rate of 0.4 mL x min(-1). Mass spectrometric detection was operated on a triple quadrupole tandem mass spectrometer equipped with atmospheric pressure chemical ionization (APCI) source in positive mode.