阅读说明：本技术 一种测定肿瘤患者血浆中替加氟、吉美嘧啶和5-氟尿嘧啶浓度的方法 (Method for determining concentrations of tegafur, gimeracil and 5-fluorouracil in blood plasma of tumor patient ) 是由 陈涛 杨勇 钟勘 陈鑫 周林芳 潘婷 李航 温凤娇 占远 姜金方 周茂金 于 2020-12-31 设计创作，主要内容包括：本发明涉及一种测定肿瘤患者血浆中替加氟、吉美嘧啶和5-氟尿嘧啶浓度的方法,通过LC-MS/MS对血浆中替加氟、吉美嘧啶和5-氟尿嘧啶进行分析,采用蛋白沉淀预处理方法,以对应的同位素标记物为内标,采用EclipseXDB-C18柱,梯度洗脱,电喷雾电离源(ESI)串联质谱检测。本发明专一性选择性强、灵敏度高、检测快速、满足临床研究大批量样品分析需求。(The invention relates to a method for measuring concentrations of tegafur, gimeracil and 5-fluorouracil in plasma of a tumor patient, which comprises the steps of analyzing the tegafur, the gimeracil and the 5-fluorouracil in the plasma by LC-MS/MS, adopting a protein precipitation pretreatment method, taking a corresponding isotope marker as an internal standard, adopting an eclipse XDB-C18 column, gradient elution and electrospray ionization source (ESI) tandem mass spectrometry detection. The invention has strong specificity and selectivity, high sensitivity and quick detection, and meets the analysis requirements of clinical research on a large number of samples.)

1. A method for determining the concentration of tegafur, gimeracil and 5-fluorouracil in the plasma of a patient with a tumour, comprising the steps of:

pretreating, collecting plasma, adding an internal standard solution, adding acetonitrile, carrying out vortex and centrifugation, taking supernatant, carrying out blow-drying concentration in nitrogen flow, dissolving residues by using a double solvent, and carrying out vortex mixing to obtain a sample to be detected;

and (2) performing chromatography, namely performing liquid chromatography separation on a sample to be detected, performing gradient elution by adopting an Eclipse XDB-C18 column, and performing gradient elution on a mobile phase A: the volume ratio of the mobile phase B is 95:5, and the volume ratio of the mobile phase A to the mobile phase B is within 3.10-3.40 min: the volume ratio of the mobile phase B is 60:40, and the volume ratio of the mobile phase A to the mobile phase B is within 3.60-6.00 min: the volume ratio of the mobile phase B is 95:5, the flow rate is 0.8000mL/min, the column temperature is 40 ℃, the temperature of an automatic sample injector is 4 ℃, the sample injection amount is 10.00 mu L, the mobile phase A is 0.005% formic acid aqueous solution, and the mobile phase B is methanol;

mass spectrometry using electrospray ion source, negative ion detection, ejection voltage-4500V, endogenous Gas 1(Gas1)60psi, Gas 2(Gas2)60psi, air Curtain Gas (Curtain Gas)35psi, ion source temperature 400 deg.C, collision induced dissociation 8psi, residence time 80ms, tegafur quantitative analysis ion pair m/z 199.1 → 42.1, Collision Energy (CE) -37.0eV, declustering voltage (DP) -21.0V, gimeracil quantitative analysis ion pair m/z143.9 → 64.0, Collision Energy (CE) -25.0eV, declustering voltage (DP) -63.0V, 5-fluorouracil quantitative analysis ion pair m/z 128.8 → 42.1, Collision Energy (CE) -36.0eV, declustering voltage (DP) -21.0V,¹³C¹⁵N₂tegafur quantitative analysis ion pair m/z 202.0 → 44.0, Collision Energy (CE) -37.0eV, declustering voltage (DP) -21.0V,¹³C₃gimeramidine quantitative analysis ion pair m/z 147.0 → 67.0, Collision Energy (CE) -25.0eV, declustering voltage (DP) -63.0V,¹³C¹⁵N₂fluorouracil quantitative analysis ion pair m/z 132.0 → 44.0, Collision Energy (CE) -36.0eV, declustering voltage (DP) -21.0V.

2. The method of claim 1 for determining the concentration of tegafur, gimeracil and 5-fluorouracil in the plasma of a patient with a tumor, wherein: and the step of pretreatment, namely taking 50.0 mu L of plasma sample, adding 25.0 mu L of internal standard solution, adding 200 mu L of acetonitrile, carrying out vortex flow and centrifugation, taking 100 mu L of supernatant, carrying out blow-drying concentration on the supernatant in nitrogen flow, dissolving the residue in 120 mu L of complex solvent, and carrying out vortex mixing to obtain the sample to be detected.

3. A method for determining the concentration of tegafur, gimeracil and 5-fluorouracil in the plasma of a patient with a tumour according to claim 1 or 2, characterized in that: the internal standard solution is¹³C¹⁵N₂-tegafur,¹³C₃-gimeracil,¹³C¹⁵N₂-fluorouracil mixed solution.

4. The method of claim 1 for determining the concentration of tegafur, gimeracil and 5-fluorouracil in the plasma of a patient with a tumor, wherein: the chromatographic procedure, Eclipse XDB-C18 column mobile phase A additive was formic acid.

Technical Field

The invention belongs to the technical field of biological medicines, and particularly relates to a method for measuring concentrations of tegafur, gimeracil and 5-fluorouracil in plasma of a tumor patient.

Background

Tigio capsules were developed by Taiho in japan and first marketed in japan in 1999 for clinical use in the treatment of gastric cancer, head and neck cancer, colorectal cancer, non-small cell lung cancer, breast cancer, and pancreatic cancer. The tegafur-gimeracil-ao capsule is a first-line medicine for treating advanced gastrointestinal malignant tumors. The tegafur-gimeracil capsule comprises three main medicinal components of tegafur, gimeracil and oteracil potassium. Wherein the tegafur is converted into an active product 5-fluorouracil in vivo to exert the drug effect. In order to advance the research and development of the tegafur capsule imitation drug, the concentration level of various drug components in blood needs to be monitored to obtain pharmacokinetic characteristics so as to evaluate the bioequivalence of the original drug and the imitation drug. Ke Liu, equal to 2010, develops a liquid chromatography-tandem mass spectrometry method for simultaneously measuring tegafur, gimeracil and 5-fluorouracil, the lower limit of the quantitation of the three substances is respectively 12.0, 2.00 and 2.00ng/mL, and the sensitivity of the method for measuring 5-fluorouracil is not enough to completely describe the pharmacokinetic characteristics of the substances. In addition, the chromatographic running time of the method is longer than 7.5min, which is not beneficial to the determination of large-scale clinical research samples. Secondly, the quantitative lower limit signal-to-noise ratio of each component to be detected is lower, the tegafur, the gimeracil and the 5-fluorouracil are respectively about 3, 2 and 5, and obvious interference peaks exist, so that large deviation is easily generated when a low-concentration sample is detected.

Disclosure of Invention

In order to solve the technical problems, the invention aims to provide a method for measuring the concentrations of tegafur, gimeracil and 5-fluorouracil in the plasma of a tumor patient, which improves the sensitivity and selectivity of the method and shortens the analysis time as much as possible so as to improve the accuracy and flux of the analysis.

In order to achieve the purpose, the invention adopts the following technical scheme:

a method for determining the concentration of tegafur, gimeracil and 5-fluorouracil in the plasma of a patient with a tumour, comprising the steps of:

pretreating, collecting plasma, adding an internal standard solution, adding acetonitrile, carrying out vortex and centrifugation, taking supernatant, carrying out blow-drying concentration in nitrogen flow, dissolving residues by using a double solvent, and carrying out vortex mixing to obtain a sample to be detected;

and (2) performing chromatography, namely performing liquid chromatography separation on a sample to be detected, performing gradient elution by adopting an Eclipse XDB-C18 column, and performing gradient elution on a mobile phase A: the volume ratio of the mobile phase B is 95:5, and the volume ratio of the mobile phase A to the mobile phase B is within 3.10-3.40 min: the volume ratio of the mobile phase B is 60:40, and the volume ratio of the mobile phase A to the mobile phase B is within 3.60-6.00 min: the volume ratio of the mobile phase B is 95:5, the flow rate is 0.8000mL/min, the column temperature is 40 ℃, the temperature of an automatic sample injector is 4 ℃, the sample injection amount is 10.00 mu L, the mobile phase A is 0.005% formic acid aqueous solution, and the mobile phase B is methanol;

mass spectrometry using electrospray ion source, negative ion detection, ejection voltage-4500V, endogenous Gas 1(Gas1)60psi, Gas 2(Gas2)60psi, air Curtain Gas (Curtain Gas)35psi, ion source temperature 400 deg.C, collision induced dissociation 8psi, residence time 80ms, tegafur quantitative analysis ion pair m/z 199.1 → 42.1, Collision Energy (CE) -37.0eV, declustering voltage (DP) -21.0V, gimeracil quantitative analysis ion pair m/z143.9 → 64.0, Collision Energy (CE) -25.0eV, declustering voltage (DP) -63.0V, 5-fluorouracil quantitative analysis ion pair m/z 128.8 → 42.1, Collision Energy (CE) -36.0eV, declustering voltage (DP) -21.0V,¹³C¹⁵N₂tegafur quantitative analysis ion pair m/z 202.0 → 44.0, Collision Energy (CE) -37.0eV, declustering voltage (DP) -21.0V,¹³C₃gimeramidine quantitative analysis ion pair m/z 147.0 → 67.0, Collision Energy (CE) -25.0eV, declustering voltage (DP) -63.0V,¹³C¹⁵N₂fluorouracil quantitative analysis ion pair m/z 132.0 → 44.0, Collision Energy (CE) -36.0eV, declustering voltage (DP) -21.0V.

Preferably, in the pretreatment step, 50.0 μ L of a plasma sample is taken, 25.0 μ L of an internal standard solution is added, 200 μ L of acetonitrile is added, 100 μ L of supernatant is taken after vortex flow and centrifugation and dried and concentrated in nitrogen flow, residues are dissolved by 120 μ L of a double solvent, and the mixture is vortex flow and mixed to form the sample to be detected.

Preferably, the method for determining the concentrations of tegafur, gimeracil and 5-fluorouracil in the plasma of a tumor patient comprises the step of adding an internal standard solution¹³C¹⁵N₂-tegafur,¹³C₃-gimeracil,¹³C¹⁵N₂-fluorouracil mixed solution.

Preferably, the method for determining the concentrations of tegafur, gimeracil and 5-fluorouracil in the plasma of a patient with a tumor is carried out by mass spectrometry using negative ion detection.

Preferably, said method for determining the concentration of tegafur, gimeracil and 5-fluorouracil in the plasma of a patient with tumours, said chromatographic step, Eclipse XDB-C18 column mobile phase A additive is formic acid.

By the scheme, the invention at least has the following advantages:

1. the invention has good selectivity, and baseline separation can be obtained by fewer chromatographic interference peaks of each compound. The invention has higher sensitivity, the concentrations of the tegafur, the gimeracil and the 5-fluorouracil are 10.0/2.00/1.00ng/mL, wherein the fluorouracil has 2 times of sensitivity compared with the prior art, and the signal-to-noise ratios are respectively 20, 40 and 30 which are far better than the prior art.

2. The invention has fast detection speed, the detection time is 6.0min, which is 20% faster than the prior art, and is suitable for the analysis of large-scale clinical research samples.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a chemical structural formula of tegafur.

FIG. 2 is a chemical structural formula of gimeracil.

FIG. 3 is a chemical structural formula of 5-fluorouracil.

FIG. 4 is¹³C¹⁵N₂-tegafur chemical formula.

FIG. 5 is¹³C₃-gemfibrozil chemical formula.

FIG. 6 is¹³C¹⁵N₂-fluorouracil chemical structural formula.

FIG. 7 is a scanning mass spectrum of Tegafur ion.

Figure 8 is gimeracil ion scanning mass spectrum.

FIG. 9 is a 5-fluorouracil ion scanning mass spectrum.

FIG. 10 is¹³C¹⁵N₂-tegafur ion scanning mass spectrum.

FIG. 11 is¹³C₃Gemfibrozil ion scanning mass spectrum.

FIG. 12 is¹³C¹⁵N₂-fluorouracil ion scanning mass spectrum.

FIG. 13 is MRM chromatograms of 5-fluorouracil in blank plasma (top left), lower limit of quantitation (middle left) and after 1h of patient oral tegafur capsule (bottom left), with internal standards corresponding one-to-one to the left on the right¹³C¹⁵N₂MRM chromatogram of fluorouracil.

FIG. 14 is MRM chromatograms of gimeracil in blank plasma (top left), bottom limit of quantitation (middle left) and after 1h of patient oral tikitiki' ao capsule (bottom left), with internal standards corresponding one-to-one to the left on the right¹³C₃MRM chromatogram of gimeracil.

FIG. 15 shows tegafur in blank plasma (upper left), lower limit of quantitation (middle left) and oral tegafur administration to patientsMRM chromatogram of Jiao capsule after 1h (lower left), wherein the right side is internal standard corresponding to the left side one by one¹³C¹⁵N₂-MRM chromatogram of tegafur.

FIG. 16 is a concentration-time curve of the postprandial oral 50mg tegafur capsule drug in 1 tumor patient.

Detailed Description

The present invention will be described in further detail with reference to the following specific examples and drawings, and the present invention is not limited to the following examples. Variations and advantages that may occur to those skilled in the art may be incorporated into the invention without departing from the spirit and scope of the inventive concept, and the scope of the appended claims is intended to be protected. The procedures, conditions, reagents, experimental methods and the like for carrying out the present invention are general knowledge and common general knowledge in the art except for the contents specifically mentioned below, and the present invention is not particularly limited.

The development of a method for detecting the concentration of a drug in blood plasma by liquid chromatography-tandem mass spectrometry can be generally divided into three parts, namely an extraction method (namely a pretreatment method), a liquid chromatography method and a mass spectrometry method. The invention aims at the defects of the prior art and sets up a detection method from the three aspects.

Examples

Pretreatment

The method uses the protein precipitation method, has high recovery rate to polar substances, and has the advantages of simple operation, short extraction time and high suitability for high-throughput sample pretreatment in clinical research.

As shown in fig. 1 to 6, the specific pretreatment method comprises the following steps:

1. add 50.0. mu.L of plasma sample to 96-well plate;

2. adding 25.0 μ L of internal standard solution (FT-¹³C,¹⁵N₂、CDHP-¹³C₃、5-FU-¹³C,¹⁵N₂Concentrations were 1500/300/150ng/mL, respectively);

3. adding 200 mu L of acetonitrile; vortex shaking for 10min, centrifuging (4 deg.C) for 10min (4500 rpm);

4. taking 100 mu L of supernatant, drying and concentrating in nitrogen flow;

5. dissolving the residue with 120 μ L of complex solvent, mixing with vortex, and performing LC-MS/MS analysis in an automatic sample injector;

6. the injection volume was 10.0. mu.L.

Mass spectrometry

Using an electrospray ion source, negative ion detection, spray voltage-4500V, endogenous Gas 1(Gas1)60psi, Gas 2(Gas2)60psi, air Curtain Gas (Curtain Gas)35psi, ion source temperature 400 deg.C, collision induced dissociation 8psi, residence time 80ms, Tegafur quantitive ion pair m/z 199.1 → 42.1, Collision Energy (CE) -37.0eV, declustering voltage (DP) -21.0V, gimeracil quantitive ion pair m/z143.9 → 64.0, Collision Energy (CE) -25.0eV, declustering voltage (DP) -63.0V, 5-fluorouracil quantitive ion pair m/z 128.8 → 42.1, Collision Energy (CE) -36.0eV, declustering voltage (DP) -21.0V,¹³C¹⁵N₂tegafur quantitative analysis ion pair m/z 202.0 → 44.0, Collision Energy (CE) -37.0eV, declustering voltage (DP) -21.0V,¹³C₃gimeramidine quantitative analysis ion pair m/z 147.0 → 67.0, Collision Energy (CE) -25.0eV, declustering voltage (DP) -63.0V,¹³C¹⁵N₂fluorouracil quantitative analysis ion pair m/z 132.0 → 44.0, Collision Energy (CE) -36.0eV, declustering voltage (DP) -21.0V.

As shown in fig. 7, 8, 9, 10, 11 and 12, fig. 7 is a tegafur ion scanning mass spectrum, fig. 8 is a gimeracil ion scanning mass spectrum, fig. 9 is a 5-fluorouracil ion scanning mass spectrum, and fig. 10 is a¹³C¹⁵N₂-tegafur ion scanning mass spectrum, fig. 11 is¹³C₃Gemfibrozil ion scanning mass spectrum, FIG. 12 is¹³C¹⁵N₂-fluorouracil ion scanning mass spectrum.

The structures of tegafur, gimeracil and 5-fluorouracil contain acidic groups, and can generate higher and remarkable precursor ions of m/z 199.1, m/z143.9 and m/z 128.8 respectively in a mass spectrum negative ion detection mode. Product ion scanning (CID) was performed on the above ions, with major fragment ions of m/z 42.1, m/z 64.0 and m/z 42.1, respectively, as product ion members for quantitative analysis of tegafur, gimeracil and 5-fluorouracil monitoring. The tegafur and gimeracil both contain basic nitrogen atoms and are easy to generate positive ion precursor ions, but the analysis time can be prolonged by using positive and negative ion switching due to the simultaneous analysis of the three compounds, and the response of the tegafur and gimeracil in a negative ion mode can also meet the requirement of biological analysis, so that the negative ion mode is used for analysis.

Chromatography

Separating the sample to be detected by liquid chromatography, adopting an Eclipse XDB-C18 column, carrying out gradient elution, and at 0min, carrying out mobile phase A: the volume ratio of the mobile phase B is 95:5, and the volume ratio of the mobile phase A to the mobile phase B is within 3.10-3.40 min: the volume ratio of the mobile phase B is 60:40, and the volume ratio of the mobile phase A to the mobile phase B is within 3.60-6.00 min: the volume ratio of the mobile phase B is 95:5, the flow rate is 0.8000mL/min, the column temperature is 40 ℃, the temperature of an automatic sample injector is 4 ℃, the sample injection amount is 10.00 mu L, the mobile phase A is 0.005% formic acid aqueous solution, the mobile phase B is methanol, and the length and the diameter of an Eclipse XDB-C18 column are 150mm and 4.6 mm.

The polarity of the tegafur, the gimeracil and the 5-fluorouracil is strong, and the tegafur, the gimeracil and the 5-fluorouracil are not easy to retain, so that the method adopts a gradient elution mode, and the initial flow phase ratio is low, so that the chromatographic retention is facilitated. The three components to be detected and the internal standard have different polarities, and the gradient elution can ensure that all the components can be eluted in a short time. The mass spectrometric detection method adopts an ionization mode of negative ions, and the retention of gimeracil on a chromatographic column can be enhanced by adding a trace amount of formic acid in a mobile phase, but the mass spectrometric response of other compounds is not influenced. The mobile phase is acidic due to the addition of trace amount of formic acid, and the invention adopts an Eclipse XDB-C18 column, has wide pH application range and can tolerate the acidic mobile phase. The running time of the chromatogram is only 6.0min, and the detection is fast and suitable for detecting a large batch of samples in clinical research.

The first embodiment is as follows:

description of abbreviations

1 Material

1.1 instruments

Chromatograph: LC-30AD flash liquid chromatography system, Shimadzu, Japan.

Mass spectrometry: 6500⁺A model triple quadrupole tandem mass spectrometer was equipped with an electrospray ionization source (Turbo Ion Spray) Sciex, Canada.

The data processing adopts software: analyst (version 1.6.3), Sciex, Canada.

A centrifuge: model Her μ Le Z2326K bench centrifuge, Haemomer, Germany.

Analytical balance: model CPA225D analytical balance, beijing sidoris instruments ltd.

1.2 control and reagents

Tegafur (content 99.71%), gimeracil (purity 99.55%), and 5-fluorouracil (purity 99.85%) were purchased from Dalian Meiren Biotechnology Ltd.¹³C¹⁵N₂-tegafur,¹³C₃-gimeracil,¹³C¹⁵N₂Fluorouracil is available from TRC. Methanol (HPLC grade), acetonitrile (HPLC grade) were purchased from Sigma company, usa. Deionized water (18.2m Ω, TOC. ltoreq.50 ppb) was prepared from a Milli-Q ultrapure water system, France.

2 method

2.1 preparation of solutions and samples

Standard series of samples: accurately weighing a proper amount of each reference substance, dissolving with methanol respectively, and fixing the volume to prepare stock solutions with the concentrations of tegafur, gimeracil and 5-fluorouracil of about 1.00 mg/mL. Precisely sucking appropriate amount of respective stock solutions, diluting with human blank plasma step by step to obtain mixed standard series samples, wherein the concentration ranges of tegafur, gimeracil and 5-fluorouracil are 10.0-3000, 2.00-600 and 1.00-300ng/mL respectively.

Quality control of the sample: four concentration level mixed quality control samples of tegafur, gimeracil and 5-fluorouracil are prepared by a method similar to that of a standard series of samples. The lower limit concentration of quantification is 0.200/0.0400/0.0200ng/mL, the concentration of Low Quality Control (LQC) is 0.500/0.100/0.0500, the concentration of Medium Quality Control (MQC) is 12.0/2.40/1.20ng/mL, and the concentration of High Quality Control (HQC) is 45.0/9.00/4.50 ng/mL.

Internal standard solution: precision weighing¹³C¹⁵N₂-tegafur,¹³C₃-gimeracil,¹³C¹⁵N₂Fluorouracil control, dissolved in methanol and made up to volume, to give an internal standard stock solution with a concentration of about 1.00 mg/mL. Precisely sucking appropriate amount of the internal standard stock solutions, adding methanol: water (50:50, v/v) dilution gave an internal standard solution at a concentration of 1500/300/150 ng/mL.

2.2 plasma sample treatment

50.0. mu.L of plasma sample was added to a 96-well plate, and 25.0. mu.L of internal standard solution (FT-¹³C,¹⁵N₂、CDHP-¹³C₃、5-FU-¹³C,¹⁵N₂Concentration of 1500/300/150ng/mL respectively), 200. mu.L acetonitrile was added; vortex for 2min, centrifuge for 5min (14000rpm), take 100. mu.L of supernatant and blow dry concentrate in nitrogen stream. The residue was dissolved in 120. mu.L of a double solvent, vortexed, and placed in an autosampler for LC-MS/MS analysis in a sample volume of 10.0. mu.L.

2.3 chromatographic and Mass Spectrometry conditions

Chromatographic conditions

A chromatographic column: eclipse XDB-C18, 110A, 5 μm, 4.6X 150mm, Agilent.

Mobile phase A: 0.005% aqueous formic acid.

Mobile phase B: methanol.

Carrying out gradient elution on the mixture,

column temperature: 40 deg.C

Flow rate: 0.8000mL/min

Sample introduction amount: 10.0. mu.L

Autosampler temperature: 4 ℃ is prepared.

Conditions of Mass Spectrometry

Adopting an electrospray ion source, detecting negative ions, spraying voltage is-4500V, endogenous Gas 1(Gas1)60psi, Gas 2(Gas2)60psi and Gas curtain Gas (Cu)rtain Gas)35psi, ion source temperature 400 ℃, collision induced dissociation 8psi, residence time 80ms, tegafur quantitation ion pair m/z 199.1 → 42.1, Collision Energy (CE) -37.0eV, declustering voltage (DP) -21.0V, gimeracil quantitation ion pair m/z143.9 → 64.0, Collision Energy (CE) -25.0eV, declustering voltage (DP) -63.0V, 5-fluorouracil quantitation ion pair m/z 128.8 → 42.1, Collision Energy (CE) -36.0eV, declustering voltage (DP) -21.0V,¹³C¹⁵N₂tegafur quantitative analysis ion pair m/z 202.0 → 44.0, Collision Energy (CE) -37.0eV, declustering voltage (DP) -21.0V,¹³C₃gimeramidine quantitative analysis ion pair m/z 147.0 → 67.0, Collision Energy (CE) -25.0eV, declustering voltage (DP) -63.0V,¹³C¹⁵N₂fluorouracil quantitative analysis ion pair m/z 132.0 → 44.0, Collision Energy (CE) -36.0eV, declustering voltage (DP) -21.0V.

2.4 methodological validation

The methodology of the method was verified according to the U.S. FDA guidelines, including stability, selectivity, linearity, accuracy, precision, recovery matrix effect, etc.

Selectivity is

Six blank blood plasma with different sources and respectively prepared quantitative lower limit samples are taken for processing and then sample injection analysis is carried out. The peak area of the chromatogram co-outflow interferent is required to be smaller than 1/5 of the peak area of the quantitative lower limit analyte and smaller than 1/20 of the peak area of the internal standard.

Standard curve

Linear regression equation (weight factor W is 1/x) calculated by regression analysis with the concentration of the physical theory to be measured as abscissa (x) and the peak area ratio of the substance to be measured to the internal standard substance as ordinate (y)²). The method verifies that each analysis batch is analyzed against a double sample of standard curve samples.

Precision and accuracy

The method verifies that each analysis batch determines six samples of five concentration quality control samples. Quantitative lower limit intra-and inter-batch precision is acceptable at less than 20% as calculated by Relative Standard Deviation (RSD) and accuracy is acceptable at between-20% and 20% as calculated by relative deviation (RE). The precision of the QC samples of other concentration levels in each component batch and between batches is required to be less than 15 percent to be acceptable, and the precision is between-15 percent and 15 percent to be acceptable.

Stability of

And (3) when the stability of each object to be detected in the plasma sample is inspected, placing the LQC and the HQC in different temperatures and environments, and analyzing the three samples after the placing is finished. A total of four placement conditions were examined, which were: standing at room temperature for 24h, extracting, standing in a sample holder for 128h, and performing 6 freeze-thaw cycles (from-75 + -10 deg.C to ice room temperature), and standing at-75 + -5 deg.C for 233 days.

Recovery rate

Taking blank plasma 50.0 μ L, adding the solution to be measured and the internal standard solution after extraction (without adding the internal standard solution) to make the final concentration the same as LQC, MQC and HQC, and carrying out sample injection determination. And 6 parts of each of LQC, MQC and HQC are extracted, and the sample injection and the determination are carried out. The extraction recovery rate was calculated from the peak area ratios of the 2 treatments.

Matrix effect

Taking 6 blank plasma with different sources, extracting (without adding an internal standard solution), taking all acetonitrile layer liquid, adding a solution to be measured and an internal standard solution with the same concentration as that of LQC and HQC, mixing by vortex, and measuring. And treating with deionized water instead of blood plasma by the above method. The ratio of the peak areas obtained by the two methods is used for calculating the matrix factor, and the matrix effect is evaluated by the RSD of the matrix factor, wherein the matrix factor is acceptable when the ratio is less than 15%.

2.5 clinical study

The established method is applied to determine the concentrations of tegafur, gimeracil and 5-fluorouracil in plasma, and the method is used for the human body bioequivalence research of tegafur capsules. Clinical studies were approved by the hospital ethics committee, and patients were informed of trial risk prior to the trial and voluntarily signed an informed consent. Fasting and postprandial administration of 50mg tegafur capsules was given to 60 tumor patients in each group. Before administration (0h), 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 4h, 6h, 8h, 10h, 12h, 24h and 48h after administration, 4mL of blood is taken from veins, placed in a heparin anticoagulation centrifuge tube, centrifuged (1700g, 4 ℃) for 10min, and then plasma is separated and stored at the temperature of-75 +/-10 ℃.

3 results and discussion

3.1 methodological validation

Selectivity of the process

As shown in fig. 13 to 15, the retention times of tegafur, gimeracil and 5-fluorouracil were about 5.1, 4.4 and 2.9min, respectively, and the interference peaks at the retention time of 5-fluorouracil were separable from the baseline. The signal-to-noise ratios of the tegafur, gimeracil and 5-fluorouracil quantitative lower limit samples were about 20, 40 and 30, respectively.

Standard curve

The linear ranges of tegafur, gimeracil and 5-fluorouracil in plasma of a tumor patient are respectively 10.0-3000 ng/mL, 2.00-600 ng/mL and 1.00-300 ng/mL. The linear average regression equation (first batch verified by methodology) of the standard curve of the object to be tested is respectively as follows:

tegafur, y-0.00146 x + 0.000289;

gemfibrozil, y is 0.00669x + 0.000601;

y is 0.0185x + 0.000278.

Precision and accuracy of the method

Precision accuracy results all meet the acceptance criteria and are shown in table 1, wherein the precision and accuracy of tegafur, gimeracil and 5-fluorouracil in plasma of tumor patients are determined in table 1.

TABLE 1

Recovery rate of treatment

LQC, MQC and HQC concentration levels: the extraction recovery rates of the tegafur are 40.1%, 38.6% and 35.3% respectively; the extraction recovery rates of the gimeracil are respectively 37.1%, 36.8% and 35.6%; the extraction recovery rates of the 5-fluorouracil are respectively 38.5%, 39.3% and 38.0%; internal standard¹³C¹⁵N₂-the recovery of tegafur is; internal standard¹³C¹⁵N₂-a recovery of tegafur of 33.5%; internal standard¹³C¹⁵N₂Recovery of-fluorouracil was 35.5%.

Matrix effect

The matrix factors of tegafur at the concentration levels of LQC and HQC are respectively 100.1% and 99.9%, and the RSD is respectively 0.8% and 0.2%; the Gimeracil matrix factors are 87.2 percent and 87.2 percent respectively, and the RSD is 0.6 percent and 0.1 percent respectively; the 5-fluorouracil matrix factor is 119.7% and 119.0%, and the RSD is 0.5% and 0.4%, respectively. The above results indicate that the matrix does not interfere with the quantitative analysis of the analyte.

Plasma stability study

The results of the plasma stability test are shown in table 2, and the results show that under the investigation conditions, tegafur, gimeracil and 5-fluorouracil are stable. Wherein, table 2 is the stability of tegafur, gimeracil and 5-fluorouracil in human plasma (n ═ 6).

TABLE 2

4 bioequivalence study

The verified method is used for simultaneously and quantitatively detecting tegafur, gimeracil and 5-fluorouracil in plasma to evaluate the bioequivalence of the tegafur capsule. The plasma drug concentration-time curve after oral administration of 50mg tegafur capsule in 1 patient is shown in FIG. 16. The invention has good selectivity, and the 5-fluorouracil interference peak can be separated from the base line. The invention has high sensitivity, improves the signal-to-noise ratio by 7, 20 and 12 times compared with the prior art, and can completely describe the pharmacokinetic characteristics of tegafur, gimeracil and 5-fluorouracil.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, it should be noted that, for those skilled in the art, many modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.