Drug interaction evaluation of the novel phosphodiesterase type 5 inhibitor tunodafil (youkenafil): effects of tunodafil on omeprazole pharmacokinetics based on CYP2C19 gene polymorphism, and effects of ritonavir on tunodafil pharmacokinetics.

Purpose: To evaluate the drug-drug interactions (DDI) of tunodafil (youkenafil), a novel phosphodiesterase type 5 inhibitor, its inhibitory effects on CYP450 enzymes in vitro and its clinical trials in combination with ritonavir or omeprazole were conducted.

Methods: The inhibitory effect of tunodafil on seven major CYP450 enzymes in human liver microsomes was investigated by probe substrate method. The effect of tunodafil on the pharmacokinetics of omeprazole (CYP2C19 substrate) in 40 healthy subjects, who received a single dose of 40 mg omeprazole in combination with tunodafil on the day 8 after taking 100 mg tunodafil daily for 7 days, was assessed based on CYP2C19 genotypes.

LC-MS/MS method for dual-ligand peptide-drug CBP-1018 and its deconjugated payload MMAE including sample stabilization strategy for its MC-Val-Cit-PABC linker.

Recently, peptide-drug conjugate (PDC) has become the most promising conjugated drug for tumor therapy after antibody-drug conjugate due to stronger tumor penetration capacity and lower immunogenicity. CBP-1018 was a PDC with dual-ligand conjugated to MMAE via a cleavable linker (MC-Val-Cit-PABC) that can be lysed by cathepsins B. In this study, two specific LC-MS/MS methods were developed and validated for the determination of CBP-1018 and its metabolite MMAE in human plasma.

Pharmacokinetics, metabolite profiling, safety and tolerability of YZJ-4729 tartrate, a novel G protein-biased μ-opioid receptor agonist, in healthy Chinese subjects.

YZJ-4729 is a novel G protein-biased μ-opioid receptor agonist for the treatment of acute pain in adult patients who require intravenous opioid analgesic therapy. The aim of this study was to assess the pharmacokinetics, metabolite profiling, safety and tolerability of YZJ-4729 in healthy Chinese subjects following the single intravenous doses ranged from 0.2 mg to 6 mg.

The metabolite profiling of YR-1702 injection in human plasma, urine and feces by HPLC-Q-TOF-MS/MS.

YR-1702, a hybrid μ/κ/δ receptor agonist, is modified from the traditional opioid analgesic dezocine. It had shown both excellent analgesic effect and lower addiction in phase I clinical trial in China, however, the metabolic pathway of YR-1702 in humans remains unelucidated.The goals of this study are to characterise the metabolism of YR-1702 in human liver microsomes (HLMs) and patients with chronic non-cancer pain by high performance liquid chromatography-coupled with quadrupole-time-of-flight mass spectrometry (HPLC-Q-TOF-MS/MS).

Development and validation of LC-MS/MS methods for the quantification of 101BHG-D01, a novel, long-acting and selective muscarinic receptor antagonist, and its main metabolite M6 in human plasma, urine and feces: Application to a clinical study in healthy Chinese subjects.

101BHG-D01 is a novel, long-acting and selective muscarinic receptor antagonist for the treatment of chronic obstructive pulmonary disease (COPD) and rhinorrhea in rhinitis. To support its clinical study, several liquid chromatography tandem mass spectrometry (LC-MS/MS) methods for the quantification of 101BHG-D01 and its main metabolite M6 in human plasma, urine and feces were developed. The plasma samples were prepared by protein precipitation, and the urine and fecal homogenate samples were pretreated by direct dilution, respectively.

Pharmacokinetics, metabolite profiling, safety, and tolerability of inhalation aerosol of 101BHG-D01, a novel, long-acting and selective muscarinic receptor antagonist, in healthy Chinese subjects.

101BHG-D01 is a novel, long-acting, selective muscarinic receptor antagonist for the treatment of chronic obstructive pulmonary disease (COPD). A single-site, randomized, double-blind, placebo-controlled and dose-escalation study of 101BHG-D01 inhalation aerosol was conducted to evaluate its pharmacokinetics, metabolite profiling, safety and tolerability following the single inhaled doses ranged from 20 to 900 μg in healthy Chinese subjects. After inhalation, 101BHG-D01 was absorbed rapidly into plasma with the time to maximum concentration about 5 min, and eliminated slowly with the terminal phase half-life about 30 h.

Development and validation of a highly sensitive and selective LC-MS/MS method for the determination of 15-hydroxylubiprostone in human plasma: application to a pharmacokinetic study in healthy Chinese volunteers.

Lubiprostone, a derivative of prostaglandin E1, is the first chemical-type constipation treatment approved by FDA. Lubiprostone has low systemic exposure after oral administration. Therefore, it is recommended that 15-hydroxylubiprostone, which is a dominant active metabolite of lubiprostone, be used as the pharmacokinetic evaluation indicator.

Simultaneous quantification of chlorogenic acid and taurocholic acid in human plasma by LC-MS/MS and its application to a pharmacokinetic study after oral administration of Shuanghua Baihe tablets.

An LC-MS/MS method was developed and validated for the simultaneous quantification of chlorogenic acid (CGA) and taurocholic acid (TCA) in human plasma using hydrochlorothiazide as the internal standard. The chromatographic separation was achieved on a Hedera ODS-2 column with a gradient elution using 10 mmol·L(-1) of ammonium acetate buffer solution containing 0.5% of formic acid - acetonitrile as mobile phase at a flow rate of 300 μL·min(-1).

Simultaneous determination of corynoline and acetylcorynoline in human urine by LC-MS/MS and its application to a urinary excretion study.

Corynoline and acetycorynoline, the major active components derived from Corydalis bungeana Herba, showed multiple pharmacological activities. However, quantification of the two compounds in human urine has not been reported. A simple liquid chromatography with tandem mass spectrometry method for the simultaneous determination of corynoline and acetycorynoline in human urine has been developed and fully validated.

Highly sensitive method for simultaneous determination of nine alkaloids of Shuanghua Baihe tablets in human plasma by LC-MS/MS and its application.

Shuanghua Baihe tablets (SBT) is a traditional Chinese medicinal formula which has been used to treat recurrent aphthous stomatitis for many years. To study the pharmacokinetic profiles of berberine, epiberberine, coptisine, palmatine, jatrorrhizine, magnoflorine, berberrubine, corynoline and acetylcorynoline in human after administration of SBT, a sensitive liquid chromatography-tandem mass spectrometry method was developed and fully validated for the simultaneous quantification of these nine alkaloids in human plasma. After protein precipitation, the nine alkaloids in human plasma sample was separated on a Hanbon C18 (150mm×2.

Pharmacokinetics of propafenone hydrochloride sustained-release capsules in male beagle dogs.

This paper describes the development and validation of a liquid chromatography-mass spectrometric assay for propafenone and its application to a pharmacokinetic study of propafenone administered as a new propafenone hydrochloride sustained-release capsule (SR-test), as an instant-release tablet (IR-reference) and as the market leader sustained-release capsule (Rythmol, SR-reference) in male beagle dogs (n=8). In Study A comparing SR-test with IR-reference in a crossover design T max and t 1/2 of propafenone for SR-test were significantly higher than those for IR-reference while C max and AUC were lower demonstrating the sustained release properties of the new formulation. In Study B comparing SR-test with SR-reference the observed C max and AUC of propafenone for SR-test (124.

LC-MS/MS determination and urinary excretion study of seven alkaloids in healthy Chinese volunteers after oral administration of Shuanghua Baihe tablets.

An LC-MS/MS method was developed and validated for the simultaneous determination of magnoflorine, berberrubine, jatrorrhizine, coptisine, epiberberine, palmatine and berberine in human urine. The sample preparation procedure involved the four-fold dilution of the urine samples with acetonitrile/water (1:3, v/v). The chromatographic separation was achieved on a Hedera ODS-2 column under gradient elution at a flow rate of 0.

Study on the pharmacokinetic profiles of corynoline and its potential interaction in traditional Chinese medicine formula Shuanghua Baihe tablets in rats by LC-MS/MS.

Corynoline, the major isoquinoline alkaloid component derived from Corydalis bungeana Herba, has greatly impressed many scientists due to its various pharmacological effects. However, there is little information on its pharmacokinetics. In this study, a sensitive and rapid liquid chromatography with tandem mass spectrometry method has been developed and validated for the determination of corynoline in rat plasma.