Determination of N-methylcytisine in rat plasma by UPLC-MS/MS and its application to pharmacokinetic study

The Effect of Dihydromyricetin on the Pharmacokinetics of Fluconazole in Sprague-Dawley Rat Plasma, Based on High-Performance Liquid Chromatography-Tandem Mass Spectrometry

Background

The synergistic effect of dihydromyricetin (DHM) and fluconazole (FLC) can improve the killing effect of FLC-resistant Candida albicans in vitro and in vivo. However, it is not clear whether DHM affects the pharmacokinetic characteristics of FLC.

Methods

In this study, 12 Sprague-Dawley (SD) rats were randomly divided into two groups as follows: (1) an FLC group in which rats were administered FLC only (42 mg/kg orally); (2) an FLC with the combined administration of DHM group, in which rats received an equivalent FLC dose immediately following the administration of DHM (100 mg/kg). Blood samples were collected from the ocular choroid vein of rats and converted into plasma. The concentrations of FLC in the rat plasma were then determined by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), and the related pharmacokinetic parameters were analysed. The initial mobile phase included 0.1% acetonitrile and water with gradient elution. Multiple reaction monitoring modes of m/z 307.2→220.1 for FLC, and m/z 237.1→194.2 for carbamazepine, were utilised to conduct quantitative analysis.

Results

The calibration curve of FLC in rat plasma demonstrated good linearity in the range of 0.1-30 μg/mL (r > 0.99), and the lower limit of quantification was 0.1 μg/mL. Moreover, the intra- and inter-day precision relative standard deviation of FLC was less than 9.09% and 6.51%, respectively. There were no significant differences in the pharmacokinetic parameters between the two groups.

Conclusion

The results showed that DHM administration did not significantly alter FLC pharmacokinetics in SD rat plasma.

Effects of dacomitinib on the pharmacokinetics of poziotinib in vivo and in vitro

CONTEXT

Dacomitinib and poziotinib, irreversible ErbB family blockers, are often used for treatment of non-small cell lung cancer (NSCLC) in the clinic.

OBJECTIVE

This study investigates the effect of dacomitinib on the pharmacokinetics of poziotinib in rats.

MATERIALS AND METHODS

Twelve Sprague-Dawley rats were randomly divided into two groups: the test group (20 mg/kg dacomitinib for 14 consecutive days) and the control group (equal amounts of vehicle). Each group was given an oral dose of 10 mg/kg poziotinib 30 min after administration of dacomitinib or vehicle at the end of the 14 day administration. The concentration of poziotinib in plasma was quantified by UPLC-MS/MS. Both in vitro effects of dacomitinib on poziotinib and the mechanism of the observed inhibition were studied in rat liver microsomes and human liver microsomes.

RESULTS

When orally administered, dacomitinib increased the AUC, T_max and decreased CL of poziotinib (p < 0.05). The IC₅₀ values of M1 in RLM, HLM and CYP3A4 were 11.36, 30.49 and 19.57 µM, respectively. The IC₅₀ values of M2 in RLM, HLM and CYP2D6 were 43.69, 0.34 and 0.11 µM, respectively, and dacomitinib inhibited poziotinib by a mixed way in CYP3A4 and CYP2D6. The results of the in vivo experiments were consistent with those of the in vitro experiments.

CONCLUSIONS

This research demonstrates that a drug-drug interaction between poziotinib and dacomitinib possibly exists when readministered with poziotinib; thus, clinicians should pay attention to the resulting changes in pharmacokinetic parameters and accordingly, adjust the dose of poziotinib in clinical settings.

Metabolic Changes in Mouse Plasma after Acute Diquat Poisoning by UPLC-MS/MS

Introduction:

Diquat is a fast-acting contact herbicide and plant dehydrating agent. The oral lethal dose 50 (LD50) of diquat in mice is about 125 mg/kg. The purpose of this study is to research the metabolomics in mouse plasma after acute diquat poisoning.

Method:

These mice were divided into two groups (the control group and acute diquat poisoning group). The control group was given normal saline by gavage. The acute diquat poisoning group was given 50 mg/kg diquat. UPLC-MS/MS was used to determinate the small molecule organic acid in mouse plasma.

Results:

Compare to the control group, the L-lysine, Adenine, L-Alanine, L-Valine, Lactic acid, Inosine, Adenosine, LTryptophan, L-Tyrosine, L-Arginine, L-Phenylalanine, L-Methionine, Citric acid, Fructose, L-Glutamine, Malic acid, LAspartic acid and Pyruvic acid increased in the acute diquat poisoning group (p<0.05); while the L-Histidine decreased (p<0.05).

Conclusion:

The results of metabolites increased or decreased, indicating that acute diquat poisoning induced amino acid metabolism and energy metabolism perturbations in mice.

Metabolic Changes in Rat Plasma After Epilepsy by UPLC-MS/MS

Introduction:

Epilepsy is one of the most common neurological diseases in clinical practice. The combined application of metabolomics technology plays a great advantage in the screening of biomarkers.

Methods:

In this study, Wistar rats were used as experimental subjects to model intractable epilepsy and to detect the metabolic changes of small molecules in plasma. UPLC-MS/MS was used to determine the small molecules in rat plasma. UPLC HSS C18 (2.1mm×100mm, 1.7 μm) column was used for separation, column temperature of 40°C. The initial mobile phase was acetonitrile -0.3% formic acid with gradient elution, the flow rate was 0.3 mL/min, total running time 4.0 min. Quantitative analysis was performed with multi-response monitoring (MRM).

Results:

Compared to the control group, the L-Alanine and L-Arginine decreased in the Epilepsy group (p<0.05); while Cytosine, Adenosine, L-Tyrosine, Citric acid, Fructose increased (p<0.05).

Conclusion:

In the screening of epilepsy biomarkers using metabolomics, various amino acids that lead to increased energy production and neurotransmitter imbalance play an important role in epileptic seizures.

Effects of naringenin on the pharmacokinetics of tofacitinib in rats

Context: Naringenin and tofacitinib are often used together for treatment of rheumatoid arthritis in Chinese clinics.Objective: This experiment investigates the effect of naringenin on the pharmacokinetics of tofacitinib in rats.Materials and methods: Twelve Sprague-Dawley rats were randomly divided into two groups (experimental group and control group). The experimental group was pre-treated with naringenin (150 mg/kg/day) for two weeks before dosing tofacitinib, and equal amounts of CMC-Na solution in the control group. After a single oral administration of 5 mg/kg of tofacitinib, 50 μL blood samples were directly collected into 1.5 mL heparinized tubes via the caudal vein at 0.083, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 and 24 h. The plasma concentration of tofacitinib was quantified by UPLC/MS-MS.Results: Results indicated that naringenin could significantly affect the pharmacokinetics of tofacitinib. The AUC_0-24 of tofacitinib was increased from 1222.81 ± 222.07 to 2016.27 ± 481.62 ng/mL/h, and the difference was significant (p < 0.05). Compared with the control group, the T_max was increased from 0.75 ± 0.29 to 3.00 ± 0.00 h (p < 0.05), and the MRT_(0-24) was increased from 4.90 ± 0.51 to 6.57 ± 0.66 h (p < 0.05), but the clearance was obviously decreased from 4.10 ± 0.72 to 2.42 ± 0.70 L/h/kg (p < 0.05) in experimental group. Although the C_max and t_1/2 of tofacitinib were increased, there were no significant differences (p > 0.05).Conclusions: This research demonstrated a drug-drug interaction between naringenin and tofacitinib possibly when preadministered with naringenin; thus, we should pay attention to this possibility in the clinic.

Determination of diosmetin-7-o-β-d-glucoside in rat plasma by UPLC–MS/MS

In this study, we used UPLC–MS/MS to determine diosmetin-7-o-β-d-glucoside in rat plasma and investigated its pharmacokinetics in rats. Six rats were given diosmetin-7-o-β-d-glucoside (5 mg/kg) by intravenous (i.v.) administration. The blood (150 μL) was withdrawn from the caudal vein after administration. Diazepam was used as an internal standard (IS), and a one-step acetonitrile precipitation method was used to process the plasma samples. Chromatographic separation was achieved using a UPLC BEH C18 column using a mobile phase of acetonitrile–0.1% formic acid with gradient elution. Electrospray ionization (ESI) tandem mass spectrometry in multiple reaction monitoring (MRM) mode with positive ionization was applied, 463.1 → 301.0 for diosmetin-7-o-β-d-glucoside, m/z 285.1 → 193.0 for diazepam (IS). Intra-day and inter-day precision of diosmetin-7-o-β-d-glucoside in rat plasma were less than 14%. The method was successfully applied in the pharmacokinetics of diosmetin-7-o-β-d-glucoside in rats after intravenous administration. The t1/2 of diosmetin-7-o-β-d-glucoside is 1.4 ± 0.4 h, which indicates the quick elimination.

Inhibitory Effect of Imperatorin on the Pharmacokinetics of Diazepam In Vitro and In Vivo

Background

Diazepam is a benzodiazepine drug used to treat anxiety, insomnia, and muscle spasms. Imperatorin is a phytochemical isolated from medicinal plants and is widely used in herbal medicine. The aim of this study was to investigate the interactions between imperatorin and diazepam in vitro and in vivo and to provide evidence-based guidance for the safe clinical use of the drug.

Methods

In vitro inhibition of imperatorin was assessed by incubating rat liver microsomes with diazepam to determine IC₅₀ values and the type of inhibition. For in vivo assessment, six rats were pretreated with 50 mg/kg imperatorin for two weeks, six were administered saline, and a single dose of 10 mg/kg diazepam was administered orally to both groups 30 min after the administration of imperatorin.

Results

Imperatorin inhibited the in vitro metabolism of diazepam via the competitive mechanism of CYP450. The IC₅₀ values of imperatorin to nordazepam and temazepam were 1.54 μM and 1.80 μM, respectively. The inhibitory constant values for temazepam and nordazepam were 1.24 μM and 1.29 μM, respectively. Long-term administration of imperatorin significantly increased the AUC_(0-12h), AUC_(0-∞), and Cmax of diazepam, while Vz/F and CLz/F were decreased significantly (P < 0.05). In turn, the AUC_(0-12h), AUC_(0-∞), and Cmax of nordazepam and temazepam decreased significantly, and Vz/F and CLz/F increased significantly (P < 0.05).

Conclusions

This study demonstrates that imperatorin inhibits the metabolism of diazepam both in vitro and in vivo. These results indicated that more attention should be paid when taking diazepam together with food or herbs containing IMP, although further investigation is still needed.

Effects of avitinib on the pharmacokinetics of osimertinib in vitro and in vivo in rats

BACKGROUND

Avitinib is one type of the third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) for the treatment of non-small cell lung cancer (NSCLC) with EGFR mutations. The purpose of this study was to investigate the effect of avitinib on the pharmacokinetics of osimertinib, one FDA approved third-generation TIKI, both in vitro and in vivo.

METHODS

The in vitro metabolic stability and inhibitory effect of avitinib on osimertinib were assessed with rat liver microsomes (RLM) to determine its IC₅₀ values. For the in vivo study, 18 Sprague-Dawley rats were randomly divided into three groups: the avitinib multiple dose group (30 mg/kg avitinib once daily for seven days), the avitinib single dose group (PEG200 once daily for six days and a dose of 30 mg/kg avitinib in PEG200 on day 7) and the control group (equal amounts of PEG200 once daily for seven days). Next, all rats were given osimertinib at a dosage of 10 mg/kg. UPLC/MS-MS was used for the determination of the concentration of osimertinib in plasma.

RESULTS

In vitro analysis revealed that the IC₅₀ value of osimertinib in rat liver microsomes was 27.6 μM. When rats were pretreated with avitinib, the values of AUC and MRT of the osimertinib were increased, and its C_max and T_max were significantly extended, whereas the values of CLz/F were significantly decreased (P < 0.05).

CONCLUSIONS

Both in vitro and in vivo results demonstrated that a drug-drug interaction between avitinib and osimertinib occurred and more attention should be paid when avitinib and osimertinib are synchronously administered in clinic.

KEY POINTS

SIGNIFICANT FINDINGS OF THE STUDY: Osimertinib is the only market available third-generation EGFR-TKI and it has been reported that some drugs could have drug-drug interactions with it.

WHAT THIS STUDY ADDS

For the first time, we systematically investigated the effect of avitinib, one newly developed third-generation EGFR-TKI, on the pharmacokinetics of osimertinib both in vitro and in vivo using a rat model.

UPLC-MS/MS Method for Determination of Khasianine in Mouse Blood: Application for Its Pharmacokinetic Study

Background:

The aim of this study was to determine the concentrations of khasianine in mouse whole blood sample and its application for the pharmacokinetics by a rapid, selective and sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method.

Methods:

The blood samples were preprocessed by one-step protein precipitation with acetonitrile. The study was performed on an ACQUITY I-Class UPLC system with a UPLC BEH column. Lannaconitine (internal standard, IS) and khasianine were gradient eluted by a mixture of acetonitrile and water with 0.1% formic acid at a flow rate of 0.4 mL/min. The mass spectrometer was equipped with an Electrospray Ionization (ESI) source in positive mode. The quantitative detection was performed in a multiple reaction monitoring modes at transitions m/z 722.4→70.7 for khasianine and m/z 585.3→119.9 for the corresponding IS.

Results:

The calibration curve was of good linearity ranging from 0.5 to 1000 ng/mL (r > 0.995). The Lower Limit of Detection (LLOD) and Lower Limit of Quantitation (LLOQ) were 0.2 and 0.5 ng/mL, respectively. The inter-day and intra-day precision (RSD%) were both less than 14%, and the accuracy ranged from 86.6% to 108.3%. The matrix effects were between 98.0% and 103.7%, and the average recovery was better than 67.4%.

Conclusion:

This assay established a sensitive, rapid, selective UPLC-MS/MS method which was successfully used for the pharmacokinetic study of khasianine in mouse blood, and the absolute availability of khasianine was 0.78% which exhibited a poor oral absorption.

Pharmacokinetics of Lusutrombopag, a Novel Thrombopoietin Receptor Agonist, in Rats by UPLC-MS/MS

Lusutrombopag is a second oral thrombopoietin (TPO) receptor agonist that selectively acts on human TPO receptors. In the study, UPLC-MS/MS was used to establish a selective and sensitive method to determine lusutrombopag with poziotinib as IS (internal standard) in rat plasma. Samples were prepared by precipitating protein with acetonitrile as a precipitant. Separation of lusutrombopag and poziotinib was performed on a CORTECS UPLC C18 column (2.1 ∗ 50 mm, 1.6 μm). The mobile phase (acetonitrile and water containing 0.1% formic acid) with gradient elution was set at a flow rate of 0.4 ml/min. The mass spectrometric measurement was conducted under positive ion mode using multiple reaction monitoring (MRM) of m/z 592.97 ⟶ 491.02 for lusutrombopag and m/z for poziotinib (IS) 492.06 ⟶ 354.55. The linear calibration curve of the concentration range was 2–2000 ng/ml for lusutrombopag, with a lower limit of quantification (LLOQ) of 2 ng/ml. RSD of interday and intraday precision were both no more than 9.66% with the accuracy ranging from 105.82% to 108.27%. The extraction recovery of lusutrombopag was between 82.15% and 90.34%. The developed and validated method was perfectly used in the pharmacokinetic study of lusutrombopag after oral administration in rats.

UPLC–MS/MS simultaneous determination of methamphetamine, amphetamine, morphine, monoacetylmorphine, ketamine, norketamine, MDMA, and MDA in hair

Hair is a stable specimen and has a longer detection window (from weeks to months) than blood and urine. Through the analysis of hair, the long-term information of the drug use of the identified person could be explored. Our work is to establish an ultra-performance liquid chromatography–tandem mass spectroscopy (UPLC–MS/MS) method for simultaneous determination of methamphetamine, amphetamine, morphine, monoacetylmorphine, ketamine, norketamine, 3,4-methylenedioxymethamphetamine (MDMA), and 3,4-methylenedioxyamphetamine (MDA) in hair. Methoxyphenamine was used as an internal standard. The chromatographic separation was performed on a UPLC ethylene bridged hybrid (BEH) C18 (2.1 mm × 50 mm, 1.7 μm) column using a mobile phase of acetonitrile–water with 10 mmol/L ammonium acetate solution which containing 0.05% ammonium hydroxide. The multiple reaction monitoring in positive electrospray ionization was used for quantitative determination. The intra-day and inter-day precisions (relative standard deviation [RSD]) were below 15%. The accuracy ranged between 85.5% and 110.4%, the average recovery rate was above 72.9%, and the matrix effect ranged between 92.7% and 109.2%. Standard curves were in the range of 0.05–5.0 ng/mg, and the correlation coefficients were greater than 0.995. The established UPLC–MS/MS method was applied to analyze the hair samples successfully.

Pharmacokinetic UPLC–MS/MS studies on byakangelicol after oral and intravenous administration to rats

Byakangelicol is one of coumarins from Baizhi and has been shown to inhibit the release of PGE2 from human lung epithelial A549 cells in a dose-dependent manner. A sensitive ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method was developed and full validated for the quantification of byakangelicol in rat plasma. The pharmacokinetics of byakangelicol after both intravenous (5 mg/kg) and oral (15 mg/kg) administrations were studied. Chromatographic separation was performed on an ultra-performance liquid chromatography ethylene bridged hybrid (UPLC BEH) C18 column with acetonitrile and 0.1% formic acid as the mobile phase at a flow rate of 0.4 mL/min; fargesin was used as the internal standard (IS). The following quantitative analysis of byakangelicol was utilized in the multiple reaction monitoring mode. The samples were extracted from rat plasma via protein precipitation using acetonitrile. In the concentration range of 1–2000 ng/mL, the method correlated linearity (r > 0.995) with a lower limit of quantitation (LLOQ) of 1 ng/mL. Intra-day precision was less than 11%, and inter-day precision was less than 12%. The accuracy was between 92.0% and 108.7%, the recovery was better than 89.6%, and the matrix effect was between 85.9% and 98.6%. The method was successfully applied to a pharmacokinetic study of byakangelicol after intravenous and oral administration, and the absolute bioavailability was 3.6%.

Quantitative Determination of Ginsenoside Rg1 in Rat Plasma by Ultrahigh Performance Liquid Chromatography-tandem Mass Spectrometry (UHPLC-MS/MS) and its Application in a Pharmacokinetics and Bioavailability Study

Background:

Ginsenoside Rg1 (Rg1) is the main active compound of ginseng herbs.

Objective:

The aim of this study is to develop a rapid, selective and sensitive ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method to determine the levels of Rg1 in rat plasma and investigate the pharmacokinetics and bioavailability of Rg1 in rats.

Methods:

Chromatographic separation was achieved on an UHPLC-MS/MS system with an UPLC BEH C18 column using an elution gradient of a mixture of acetonitrile and water (with 0.1% formic acid). The analytes were quantitatively determined by negative-mode electrospray tandem MS.

Results:

The linearity of the calibration curve was from 2 to 1,000 ng/mL (r ≥ 0.9956), and the lower limit of quantification was 2 ng/mL. The inter-day and intra-day precision were both lower than 12.0%, and the accuracy ranged from 90.6 to 109.7%. The recovery of the targets was higher than 87.0%, and the matrix effect at three different analyte concentrations were from 89.0 to 97.2%. The bioavailability of Rg1 was only 6.1% due to a poor oral absorption.

Conclusion:

This new quantitative method was found to be sensitive, rapid and selective, and was successfully used to study the pharmacokinetics of Rg1 after intravenous and oral administration in rats.

A rapid and sensitive UPLC-MS/MS method for the determination of flibanserin in rat plasma: application to a pharmacokinetic study

Background

In this work, we aim to develop and validate a fast, simple, and sensitive method for the quantitative determination of flibanserin and the exploration of its pharmacokinetics.

Methods

Ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was the method of choice for this investigation and carbamazepine was selected as an internal standard (IS). The plasma samples were processed by one-step protein precipitation using acetonitrile. The highly selective chromatographic separation of flibanserin and carbamazepine (IS) was realised using an Agilent RRHD Eclipse Plus C18 (2.1 × 50 mm, 1.8 µ) column with a gradient mobile phase consisting of 0.1% formic acid in water and acetonitrile. The analytes were detected using positive-ion electrospray ionization mass spectrometry via multiple reaction monitoring (MRM). The target fragment ions were m/z 391.3 → 161.3 for flibanserin and m/z 237.1 → 194 for carbamazepine (IS). The method was validated by linear calibration plots over the range of 100-120,000 ng/mL for flibanserin (R² = 0.999) in rat plasma.

Results

The extraction recovery of flibanserin was in the range of 91.5-95.8%. The determined inter- and intra-day precision was below 12.0%, and the accuracy was from - 6.6 to 12.0%. No obvious matrix effect and astaticism was observed for flibanserin. The target analytes were long-lasting and stable in rat plasma for 12 h at room temperature, 48 h at 4 °C, 30 days at - 20 °C, as well as after three freeze-thaw cycles (from - 20 °C to room temperature). The proposed method has been fully validated and successfully applied to the pharmacokinetic study of flibanserin.

Tissue Distribution of Engeletin in Mice by UPLC-MS/MS

Introduction:

Engeletin is the main active component in the engelhardia leaf that promotes circulation and removes stasis, and has hypoglycemic, hypolipidemic, and anti-inflammatory actions. The aim of this study was to develop an ultra-performance liquid chromatography- tandem mass spectrometry method to detect engeletin in plasma and tissues and investigate its absorption, distribution, and mechanism in mice, which could provide very useful information for its pharmacological effect in vivo.

Materials and Methods:

Twenty-five mice were intraperitoneally injected with 20 mg/kg engeletin, and five mice were sacrificed using 4% chloral hydrate 0.25, 0.5, 2, 4, and 6 h later. The tissues (brain, kidney, heart, liver, spleen, and lung) and blood were collected. Acetonitrile precipitation was applied to remove protein and further process the mouse plasma and tissue homogenate samples. Multiple reactions monitoring mode in negative mode was used to quantify the engeletin.

Results and Conclusion:

Linearity of engeletin in plasma and tissues was good (R2 > 0.995), within the range of 2-2,000 ng/mL in plasma and 2-2,000 ng/g in tissues, and the lower limit of quantitation was 2 ng/mL in plasma and 2 ng/g in tissues. Inter-day precision of engeletin in plasma or tissues (brain, kidney, heart, liver, spleen, and lung) was < 14%, and intra-day precision was < 15%. After the mice were intraperitoneally injected with engeletin (20 mg/kg), the distribution in kidney and liver was the highest, followed by blood, spleen, lung, heart, and brain. Engeletin concentration in the brain was low, suggesting that engeletin can penetrate through the blood brain barrier, which could also help with engeletin investigations of the brain.

Recent Advances on Drug Analyses Using Ultra Performance Liquid Chromatographic Techniques and their Application to the Biological Samples

Introduction:

Ultra-Performance Liquid Chromatographic (UPLC) method enables analyst to establish an analysis at higher pressure than High Performance Liquid Chromatographic (HPLC) method towards liquid chromatographic methods. UPLC method provides the opportunity to study a higher pressure compared to HPLC, and therefore smaller column in terms of particle size and internal diameter are generally used in drug analysis. The UPLC method has attracted gradually due to its advantages such as short analysis time, the small amount of waste reagents and the significant savings in the cost of their destruction process. In this review, the recent selected studies related to the UPLC method and its method validation are summarized. The drug analyses and the results of the studies which were investigated by UPLC method, with certain parameters from literature are presented.

Background:

Quantitative determination of drug active substances by High-Performance Liquid Chromatography (HPLC) from Liquid Chromatography (LC) methods has been carried out since the 1970's with the use of standard analytical LC methods. In today's conditions, rapid and very fast even ultra-fast, flow rates are achieved compared to conventional HPLC due to shortening analysis times, increasing method efficiency and resolution, reducing sample volume (and hence injection volume), reducing waste mobile phase. Using smaller particles, the speed and peak capacity are expanding to new limit and this technology is named as Ultra Performance Liquid Chromatography. In recent years, as a general trend in liquid chromatography, ultra-performance liquid chromatography has taken the place of HPLC methods. The time of analysis was for several minutes, now with a total analysis time of around 1-2 minutes. The benefits of transferring HPLC to UPLC are much better understood when considering the thousands of analyzes performed for each active substance, in order to reduce the cost of analytical laboratories where relevant analysis of drug active substances are performed without lowering the cost of research and development activities.

Methods:

The German Chemist Friedrich Ferdinand Runge, proposed the use of reactive impregnated filter paper for the identification of dyestuffs in 1855 and at that time the first chromatographic method in which a liquid mobile phase was used, was reviewed. Christian Friedrich Chönbein, who reported that the substances were dragged at different speeds in the filter paper due to capillary effect, was followed by the Russian botanist Mikhail S. Tswet, who planted studies on color pigment in 1906. Tswet observes the color separations of many plant pigments, such as chlorophyll and xanthophyll when he passes the plant pigment extract isolated from plant through the powder CaCO3 that he filled in the glass column. This method based on color separation gives the name of "chromatographie" chromatography by using the words "chroma" meaning "Latin" and "graphein" meaning writing.

Results and Conclusion:

Because the UPLC method can be run smoothly at higher pressures than the HPLC method, it offers the possibility of analyzing using much smaller column sizes and column diameters. Moreover, UPLC method has advantages, such as short analysis time, the small amount of waste reagents and the significant savings in the cost of their destruction process. The use of the UPLC method especially analyses in biological samples such as human plasma, brain sample, rat plasma, etc. increasingly time-consuming due to the fact that the analysis time is very short compared to the HPLC, because of the small amount of waste analytes and the considerable savings in their cost.

Pharmacokinetic Study of Deltaline in Mouse Blood Based on UPLCMS/ MS

Results:

The UPLC-MS/MS method was sensitive and linear (r>0.995) with a lower limit of quantitation (LLOQ) of 0.1 ng/mL over the range of 0.1-500 ng/mL. Intra- and inter-day precisions were below 13%, the accuracy range was between 88.0% and 108.2%, the recovery was higher than 90.1%, and the matrix effect was between 102.9% and 108.1%.

Conclusion:

The method was sensitive, fast, specific, and has been successfully applied to a pharmacokinetic study of deltaline after intravenous administration.

Determination of Puquitinib in Human Plasma by HPLC–ESI MS/MS: Application to Pharmacokinetic Study

Background and Objective

Puquitinib mesylate (XC-302) is a new multiple-target anticancer inhibitor, which directly suppresses the activity of phosphatidylinositol 3-kinase (PI3K). This study was aimed to develop a sensitive and specific liquid chromatography electrospray ionization tandem mass spectrometry (HPLC–ESI MS/MS) method for the quantification and pharmacokinetic investigation of plasma puquitinib in cancer patients.

Methods

The analytes of human plasma were prepared by liquid–liquid extraction using methyl-t-butyl ether (MTBE). The plasma analytes were separated by HPLC on Thermo ODS Hypersil column (2.1 × 150 mm; 3 μm) at 25 °C with 5 mmol/L ammonium acetate (A)-acetonitrile (B) (30:70, v/v) as the mobile phase.

Results

The total run time was 3.5 min and the elution of puquitinib was at 1.38 min. The detection were analyzed by multiple reaction monitoring (MRM) mode with positive-ion electrospray ionization (ESI) interface using the respective [M + H]⁺ ions: m/z 318.2 → 261.1 for puquitinib and m/z 258.2 → 121.0 for the internal standard (etofesalamide). The optimized method provided a good linear relation over the concentration range of 1.00-500.00 ng/mL (r = 0.9944) for puquitinib. The intra-day and inter-day precision (relative standard deviation [RSD%]) were within 9.83%, and the intra-day and inter-day accuracy ranged from 91.05 to 103.26%. The lower limit of quantitation (LLOQ) was 1.00 ng/mL. The absolute extraction recovery was on an average of 50.43% for puquitinib and 49.3% for internal standard. In addition, the maximum plasma concentration (C_max) of puquitinib in dosage from 50 to 800 mg/m² in the human study showed an increased linearly (57.1–1289.2 ng/mL), which displayed that the concentrations had reached effective levels.

Conclusions

The optimized method was successfully applied to the pharmacokinetic profile study in human cancer patient plasma after the oral administration of puquitinib.

Determination and pharmacokinetic study of AZD-3759 in rat plasma by ultra performance liquid chromatography with triple quadrupole mass spectrometer

Background

AZD‐3759 is a new, potent, oral, active central nervous system‐penetrant EGFR inhibitor. Despite promising clinical activity among patients pretreated and never treated with EGFR‐tyrosine kinase inhibitors, no time saving pharmacokinetic study method has been reported in an animal model.

Methods

Protein was precipitated with acetonitrile and then used for sample pre‐processing. A CORTECS BEH C18 column was used to separate the analytes at 40°C. Acetonitrile and water (containing 0.1% formic acid) were chosen as the mobile phase at a flow rate of 0.4 mL/min. The analytes were quantified by multiple reaction monitoring mode with positive electrospray ionization.

Results

The target fragment ions were m/z 460.38→141 for AZD‐3759 and m/z 285.1→193.1 for internal standard diazepam. The calibration curve exhibited good linearity for AZD‐3759 at a range of 1–500 ng/mL. The intra‐run and inter‐run precision variations were both < 8.22%. The recovery rate of AZD‐3759 from plasma was > 76.4%.

Conclusion

An accurate, simple ultra performance liquid chromatography with triple quadrupole mass spectrometer method was developed and validated to determine AZD‐3759 in rat plasma. Our validated method can be applied to the pharmacokinetic study of AZD‐3759 at an oral dosage of 10 mg/kg.

Pharmacokinetics and Bioavailability Study of Tubeimoside I in ICR Mice by UPLC-MS/MS

The aim of this study is to establish and validate a rapid, selective, and sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method to determine tubeimoside I (TBMS-I) in ICR (Institute of Cancer Research) mouse whole blood and its application in the pharmacokinetics and bioavailability study. The blood samples were precipitated by acetonitrile to extract the analytes. Chromatographic separation was performed on a UPLC BEH C18 column (2.1 mm × 50 mm, 1.7 μm). The mobile phase consisted of water with 0.1% formic acid and methanol (1 : 1, v/v) at a flow rate of 0.4 mL/min. The total eluting time was 4 min. The TBMS-I and ardisiacrispin A (internal standard (IS)) were quantitatively detected by a tandem mass spectrometry equipped with an electrospray ionization (ESI) in a positive mode by multiple reaction monitoring (MRM). A validation of this method was in accordance with the US Food and Drug Administration (FDA) guidelines. The lower limit of quantification (LLOQ) of TBMS-I was 2 ng/mL, and the calibration curve was linearly ranged from 2 to 2000 ng/mL (r2 ≥ 0.995). The relative standard deviation (RSD) of interday precision and intraday precision was both lower than 15%, and the accuracy was between 91.7% and 108.0%. The average recovery was >66.9%, and the matrix effects were from 104.8% to 111.0%. In this assay, a fast, highly sensitive, and reproducible quantitative method was developed and validated in mouse blood for the first time. The absolute availability of TBMS-I in the mouse was only 1%, exhibiting a poor oral absorption.

Pharmacokinetic Interaction Study of Ketamine and Rhynchophylline in Rat Plasma by Ultra-Performance Liquid Chromatography Tandem Mass Spectrometry

Eighteen Sprague-Dawley rats were randomly divided into three groups: ketamine group, rhynchophylline group, and ketamine combined with rhynchophylline group (n = 6). The rats of two groups received a single intraperitoneal administration of 30 mg/kg ketamine and 30 mg/kg rhynchophylline, respectively, and the third group received combined intraperitoneal administration of 30 mg/kg ketamine and 30 mg/kg rhynchophylline together. After blood sampling at different time points and processing, the concentrations of ketamine and rhynchophylline in rat plasma were determined by the established ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method. Chromatographic separation was achieved using a UPLC BEH C18 column (2.1 mm × 50 mm, 1.7 μm) with carbamazepine as an internal standard (IS). The initial mobile phase consisted of acetonitrile and water (containing 0.1% formic acid) with gradient elution. Multiple reaction monitoring (MRM) modes of m/z 238.1 → 179.1 for ketamine, m/z 385.3 → 159.8 for rhynchophylline, and m/z 237.3 → 194.3 for carbamazepine (IS) were utilized to conduct quantitative analysis. Calibration curve of ketamine and rhynchophylline in rat plasma demonstrated good linearity in the range of 1-1000 ng/mL (r > 0.995), and the lower limit of quantification (LLOQ) was 1 ng/mL. Moreover, the intra- and interday precision relative standard deviation (RSD) of ketamine and rhynchophylline were less than 11% and 14%, respectively. This sensitive, rapid, and selective UPLC-MS/MS method was successfully applied to pharmacokinetic interaction study of ketamine and rhynchophylline after intraperitoneal administration. The results showed that there may be a reciprocal inhibition between ketamine and rhynchophylline.

Recent advances in the application of hydrophilic interaction chromatography for the analysis of biological matrices

Hydrophilic interaction chromatography (HILIC) is being increasingly used for the analysis of hydrophilic compounds in biological matrices. The complexity of biological samples demands adequate sample preparation procedures, specifically adjusted for HILIC analyses. Currently, most bioanalytical assays are performed on bare silica and ZIC-HILIC columns. Trends in HILIC for bioanalysis include smaller particle sizes and miniaturization of the analytical column. For complex biological samples, multidimensional techniques can separate and identify more compounds than 1D separations. The high volatility of the mobile phase, the added separation power and high sensitivity make MS the detection method of choice for bioanalysis using HILIC, although other detectors such as evaporative light scattering detection, charged aerosol detection and nuclear magnetic resonance have been reported.