A method for detecting the content of losartan impurities

Abstract

The present invention relates to a method for detecting the content of losartan impurities, comprising the following steps: (1) dissolving a sample to be detected with a diluent; (2) detecting with a high performance liquid chromatography-mass spectrometry instrument containing a triple quadrupole and an electrospray ion source, wherein the impurity quantitative parent ion is 448.2, the daughter ion is 405.1, and the stationary phase of the high performance liquid chromatography is a YMC-Pack ODS-AQ chromatographic column. The present invention adopts liquid chromatography-mass spectrometry to determine losartan impurities, sets a rigorous threshold value according to the corresponding genotoxic impurity residual limit, uses a reliable analytical means to carry out targeted analysis and detection of genotoxic impurities, has strong specificity, high sensitivity, a quantitative limit of 1.0ppm, and a detection limit of 0.3ppm; at the same time, the detection accuracy is improved, the method has good reproducibility, and the relative standard deviation of continuous injection is 1.61%, which provides convenience for the analysis of losartan raw materials, thereby making the quality of losartan controllable and providing conditions for losartan to achieve industrial production.

Description

Technical Field

[0001] The present invention relates to the field of analysis and detection, and in particular to a method for detecting the content of losartan impurities. Background Art

[0002] Losartan is an oral non-peptide angiotensin II receptor antagonist, mainly used to treat essential hypertension. Its chemical name is 2-butyl-4-chloro-5-(hydroxymethyl)-1-[[2'-(1H-tetrazolyl-5-)biphenyl-4-]methyl]imidazole, and its structural formula is as follows:

[0003]

[0004] The synthesis method of losartan is disclosed in the specification of US Patent US20100190996A1, such as Figure 1 As shown, compound 2 (chemical name 4'-[(2-butyl-4-chloro-5-hydroxymethyl-1H-imidazol-1-yl)methyl]biphenyl-2-carbonitrile) generates compound 1, i.e. losartan, under the action of sodium azide and triethylamine hydrochloride. The synthesis of losartan using the above route is the mainstream process on the market. In the process of studying the synthesis of losartan by the above method, the inventors found a losartan-related impurity, the structural formula is shown in Formula I, and the chemical name is 2-butyl-4-chloro-5-(azidomethyl)-1-[[2'-(1H-tetrazolyl-5-)biphenyl-4-]methyl]imidazole. In the reaction process of compound 2 and sodium azide, the hydroxymethyl group at the 5th position of the imidazole group may react with sodium azide to obtain the impurity shown in Formula I. The impurity formula I is a Class 3 genotoxic impurity. According to the existing guidelines ICHM7, its limit is 10 ppm. It is difficult to detect and control the impurity content using liquid phase methods. The detection is not sensitive and it is difficult to accurately measure the content.

[0005]

[0006]

[0007] In the synthesis process of drugs, the control of genotoxic impurities not only determines whether the drug can be marketed, but also has a significant impact on human health. At present, there is no literature report on the detection method of the content of impurity formula I. Summary of the invention

[0008] The technical problem to be solved by the present invention is to provide a method for detecting the content of losartan impurities in view of the current status of the prior art. The method can accurately determine the content of losartan impurities by performing targeted analysis and detection on genotoxic impurities using reliable analytical means.

[0009] The technical solution adopted by the present invention to solve the above technical problems is:

[0010] A method for detecting the content of losartan impurities, the 2-butyl-4-chloro-5-(azidomethyl)-1-[[2'-(1H-tetrazolyl-5-)biphenyl-4-]methyl]imidazole, the detection method comprising the following steps:

[0011] (1) diluting a sample containing losartan impurities with a diluent to a suitable concentration, and then injecting the sample;

[0012] (2) Detection was performed using a high performance liquid chromatography-mass spectrometry instrument containing a triple quadrupole and an electrospray ion source, wherein the impurity quantitative parent ion was 448.2, the daughter ion was 405.1, the stationary phase of the high performance liquid chromatography was a YMC-Pack ODS-AQ chromatographic column, and the mobile phase was a mixture of a buffer salt and an organic solvent, wherein the volume percentage of the buffer salt was 20% to 55%, and the volume percentage of the organic solvent was 45% to 80%, the buffer salt was an ammonium salt, and the organic solvent was acetonitrile.

[0013] Preferably, the ammonium salt is ammonium acetate or ammonium formate. The mobile phase is ammonium acetate buffer solution and acetonitrile.

[0014] More preferably, the mobile phase is 10 mM ammonium acetate buffer solution and acetonitrile, and the flow rate is 0.4 mL per minute.

[0015] Preferably, the elution gradient of the mobile phase is:

[0016] Time (min) Buffer salt % Acetonitrile% 0 55 45 10 55 45 10.1 20 80 15 20 80 15.1 55 45 25 55 45 .

[0017] Preferably, the mobile phase in step (2) is 0.4 mL / min.

[0018] Preferably, the buffer salt concentration in step (2) is 5 to 10 mmol / L.

[0019] Preferably, the column temperature of the C18 chromatographic column in step (2) is 25-35°C.

[0020] Preferably, the mass spectrometry detection conditions are:

[0021]

[0022]

[0023] Compared with the prior art, the advantages of the present invention are as follows: the present invention adopts liquid chromatography-mass spectrometry to determine losartan impurities, sets a strict threshold value according to the corresponding genotoxic impurity residue limit, uses a reliable analytical means to carry out targeted analysis and detection of genotoxic impurities, has strong specificity and high sensitivity, a quantitative limit of 1.0 ppm, and a detection limit of 0.3 ppm; at the same time, the detection accuracy is improved, the method has good reproducibility, and the relative standard deviation of continuous sampling is 1.61%, which provides convenience for the analysis of losartan raw materials, thereby making the quality of losartan controllable and providing conditions for the industrial production of losartan. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The reaction flow chart of the background technology of the present invention is as follows;

[0025] Figure 2 is the mass spectrum of the blank solution in Example 1 of the present invention;

[0026] Figure 3 is the mass spectrum of the standard solution in Example 1 of the present invention;

[0027] Figure 4 This is the mass spectrum of the sample solution in Example 1 of the present invention. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below with reference to the accompanying drawings.

[0029] Embodiment 1:

[0030] In this embodiment, the detection method of losartan impurity 2-butyl-4-chloro-5-(azidomethyl)-1-[[2'-(1H-tetrazolyl-5-)biphenyl-4-]methyl]imidazole comprises the following steps:

[0031] Chromatographic column: YMC-Pack ODS-AQ150mm×4.6mm, 3μm;

[0032] Mobile phase: 10 mM ammonium acetate buffer and acetonitrile;

[0033] Flow rate: 0.4 mL / minutes, column temperature: 25 °C, injection volume: 5 μL;

[0034] Mass spectrometer detector conditions:

[0035]

[0036]

[0037] Select diluent as blank solution; take about 2.5 mg of impurity reference substance of formula I in a 50 mL volumetric flask, dissolve it in the diluent and dilute to the scale, shake well as impurity stock solution-1, take 1.0 mL of impurity stock solution-1 in a 50 mL volumetric flask, dilute it to the scale with diluent, shake well as impurity stock solution-2, take 1.0 mL of impurity stock solution-2 in a 50 mL volumetric flask, dilute it to the scale with diluent, shake well as standard solution; take 100 mg of losartan potassium in a 50 mL volumetric flask, add diluent to dissolve it by ultrasonic and dilute it to the scale, shake well as sample solution.

[0038] Accurately measure 5 μL of blank solution, standard solution, and sample solution, inject them into the LC-MS instrument, and record the mass spectrum. Figures 2 to 4 .

[0039] The test results show that the blank solution has no interference, the parent ion and daughter ion of impurity I meet the requirements, and the impurity content is calculated by external standard method. The impurity I detected in the sample is 0.77ppm, the spiked limit impurity solution is 9.11ppm, and the recovery rate is 85.7%. The results are accurate and reliable.

[0040] Embodiment 2:

[0041] The method for detecting the content of the impurity 2-butyl-4-chloro-5-(azidomethyl)-1-[[2'-(1H-tetrazolyl-5-)biphenyl-4-]methyl]imidazole in losartan in this embodiment is as follows:

[0042] Chromatographic column: YMC-Pack ODS-AQ150mm×4.6mm, 3μm;

[0043] Mobile phase: 10 mM ammonium formate buffer and acetonitrile;

[0044] Flow rate: 0.4 mL / minutes, column temperature: 35 °C, injection volume: 5 μL;

[0045] Mass spectrometer detector conditions:

[0046]

[0047]

[0048] Select diluent as blank solution; take about 2.5 mg of impurity reference substance of formula I in a 50 mL volumetric flask, dissolve it in the diluent and dilute to the scale, shake well as impurity stock solution-1, take 1.0 mL of impurity stock solution-1 in a 50 mL volumetric flask, dilute it to the scale with diluent, shake well as impurity stock solution-2, take 1.0 mL of impurity stock solution-2 in a 50 mL volumetric flask, dilute it to the scale with diluent, shake well as standard solution; take 100 mg of losartan potassium in a 50 mL volumetric flask, add diluent to dissolve it by ultrasonic and dilute it to the scale, shake well as sample solution.

[0049] Accurately measure 5 μL of blank solution, standard solution, and sample solution, inject them into the LC-MS instrument, and record the mass spectrum.

[0050] The test results show that the blank solution has no interference, the parent ion and daughter ion of impurity I meet the requirements, and the impurity content is calculated by external standard method. The impurity I detected in the sample is 0.83ppm, the spiked limit impurity solution is 8.81ppm, and the recovery rate is 86.6%. The results are accurate and reliable.

[0051] Embodiment 3:

[0052] The method for detecting the content of the impurity 2-butyl-4-chloro-5-(azidomethyl)-1-[[2'-(1H-tetrazolyl-5-)biphenyl-4-]methyl]imidazole in losartan in this embodiment is as follows:

[0053] Chromatographic column: YMC-Pack ODS-AQ150mm×4.6mm, 3μm;

[0054] Mobile phase: 10 mM ammonium formate buffer and acetonitrile;

[0055] Flow rate: 0.4 mL / minutes, column temperature: 25 °C, injection volume: 5 μL;

[0056] Mass spectrometer detector conditions:

[0057] Ion source: Electrospray ionization source ESI Atomizing gas: Nitrogen N2 Gas temperature: 350℃ Gas flow rate: 12L / min Atomizer pressure: 45psi Capillary voltage: 4000V Scan Type: MRM polarity: just Precursor ion: 448.2 Product ion: 405.1,377.1

[0058] Select diluent as blank solution; take about 2.5 mg of impurity reference substance of formula I in a 50 mL volumetric flask, dissolve it in the diluent and dilute to the scale, shake well as impurity stock solution-1, take 1.0 mL of impurity stock solution-1 in a 50 mL volumetric flask, dilute it to the scale with diluent, shake well as impurity stock solution-2, take 1.0 mL of impurity stock solution-2 in a 50 mL volumetric flask, dilute it to the scale with diluent, shake well as standard solution; take 100 mg of losartan potassium in a 50 mL volumetric flask, add diluent to dissolve it by ultrasonic and dilute it to the scale, shake well as sample solution.

[0059] Accurately measure 5 μL of blank solution, standard solution, and sample solution, inject them into the LC-MS instrument, and record the mass spectrum.

[0060] The test results show that the blank solution has no interference, the parent ion and daughter ion of impurity I meet the requirements, and the impurity content is calculated by external standard method. The impurity I detected in the sample is 0.83ppm, the spiked limit impurity solution is 8.80ppm, and the recovery rate is 86.6%. The results are accurate and reliable.

Claims

1. A method for detecting the content of losartan impurities, wherein the losartan impurity is 2-butyl-4-chloro-5-(azidomethyl)-1-[[2'-(1H-tetrazolyl-5-)biphenyl-4-]methyl]imidazole, characterized in that The detection method comprises the following steps: (1) Dissolving the sample to be tested with a diluent; (2) Detection was performed using a high performance liquid chromatography-mass spectrometry instrument containing a triple quadrupole and an electrospray ion source, wherein the impurity quantitative parent ion was 448.2, the daughter ion was 405.1, the stationary phase of the high performance liquid chromatography was a YMC-Pack ODS-AQ column, the mobile phase was a mixture of a buffer salt and an organic solvent, the volume percentage of the buffer salt was 20% to 55%, the volume percentage of the organic solvent was 45% to 80%, the buffer salt was an ammonium salt, and the organic solvent was acetonitrile; Put the impurity reference substance in a volumetric flask, dissolve the diluent and dilute to the scale, shake well as impurity stock solution-1, put the impurity stock solution-1 in a volumetric flask, dilute to the scale with the diluent, shake well as impurity stock solution-2, put the impurity stock solution-2 in a volumetric flask, dilute to the scale with the diluent, shake well as standard solution; accurately measure 5 μL of the standard solution and sample solution, inject into the liquid-mass spectrometer, record the mass spectrum, and calculate the impurity content by the external standard method; The elution gradient of the mobile phase is The mass spectrometry detection conditions were 2. The method for detecting the content of losartan impurities according to claim 1, characterized in that: The ammonium salt is ammonium acetate or ammonium formate.

3. The method for detecting the content of losartan impurities according to claim 1, characterized in that: The mobile phase is ammonium acetate buffer solution and acetonitrile.

4. The method for detecting the content of losartan impurities according to claim 1, characterized in that: The mobile phase described in step (2) was 0.4 mL / min.

5. The method for detecting the content of losartan impurities according to claim 1, characterized in that: The buffer salt concentration in step (2) is 5 to 10 mmol / L.

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