Method for detecting related substances of azilsartan and levoamlodipine tablets

Abstract

The invention belongs to the field of analytical chemistry, and discloses a method for detecting related substances in azilsartan-levoamlodipine tablets, which comprises the following steps: quantitatively detecting impurities in the azilsartan-levoamlodipine tablets by high performance liquid chromatography; wherein the impurities are an azilsartan impurity A, an azilsartan impurity B, an azilsartan impurity C, benzenesulfonic acid, an amlodipine impurity D, a deamination cyclization impurity 1, a deamination cyclization impurity 2 and a deamination cyclization impurity 3. According to the present invention, the detection method is systematically optimized so as to determine the optimal detection method of the azilsartan-levoamlodipine tablet related substance by using the liquid chromatography, and the method has characteristics of strong specificity, high sensitivity, good repeatability, safe test reagent, simple preparation and the like, further has advantages of universality, practicality and the like, and can be used for the detection of the azilsartan-levoamlodipine tablet related substance. And the operation is simpler and more efficient.

Description

Technical Field

[0001] The invention belongs to the technical field of analytical chemistry, relates to liquid chromatography, and specifically relates to a method for detecting related substances of azilsartan levoamlodipine tablets based on high performance liquid chromatography. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] Azilsartan is an angiotensin II receptor blocker that lowers blood pressure by blocking the vasopressor hormone angiotensin II; amlodipine besylate is a calcium channel blocker that lowers blood pressure by inhibiting the inward calcium channels in vascular smooth muscle cells, leading to peripheral arterial vasodilation. The combined use of the two is mainly suitable for the treatment of hypertension and angina pectoris.

[0004] At present, the detection of related substances in Azilsartan and Amlodipine Tablets is generally carried out by layered testing, but the following problems exist in the conventional layered testing of samples: ① In the layered testing, there is no obvious difference in the color of the double-layer tablets, and it is difficult to distinguish the layers; scraping the middle layer is dangerous and easy to leave residues; ② The content difference between azilsartan and amlodipine in the double-layer tablets is large, and the preparation of samples requires many instruments, which are easy to contaminate; a batch of samples needs to be injected multiple times for layered testing, which is time-consuming; ③ There are many impurities, and most single-layer tablet detection methods have the problem of difficult impurity separation. At present, there is no reported method for the detection of related substances in Azilsartan and Amlodipine Tablets, so it is of great significance to find a detection method to solve the shortcomings of the existing methods and ensure the quality of Azilsartan and Amlodipine Tablets. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention proposes a method for detecting azilsartan levoamlodipine related substances, which adopts a chromatographic column with octadecylsilane bonded silica gel as a filler; 0.02 mol / L potassium dihydrogen phosphate solution (containing 0.5% triethylamine, and the pH value is adjusted to 3.8 with phosphoric acid) as mobile phase A; acetonitrile as mobile phase B; gradient elution is set; the flow rate is 1.0 ml per minute; the column temperature is 30°C; the detection wavelength is 237 nm; and the injection volume is 10 μl. The present invention determines the optimal detection method for 8 impurities in azilsartan levoamlodipine tablets through systematic optimization and adjustment of the detection method, can trace the source of each impurity, can effectively achieve good separation of benzenesulfonic acid, azilsartan impurity A, azilsartan impurity C, amlodipine impurity D, levoamlodipine, azilsartan and azilsartan impurity B, deamination cyclization impurity 1, deamination cyclization impurity 2, and deamination cyclization impurity 3, thereby simplifying the process, improving the detection speed, and ensuring the detection accuracy of known impurities.

[0006] Specifically, the technical solution of the present invention is as follows:

[0007] The first aspect of the present invention provides a method for detecting related substances in Azilsartan Levoamlodipine Tablets, comprising:

[0008] HPLC was used to quantitatively detect impurities in azilsartan-levoamlodipine tablets;

[0009] Among them, the impurities are azilsartan impurity A, azilsartan impurity B, azilsartan impurity C, benzenesulfonic acid, amlodipine impurity D, deamination cyclization impurity 1, deamination cyclization impurity 2, and deamination cyclization impurity 3.

[0010] The present invention achieves the purpose of effectively separating eight known impurities by screening detection methods, concentrations, injection volumes, etc., shortening the detection time by more than half, reducing detection costs, avoiding operational safety hazards, and reducing the probability of deviations, thereby achieving convenience and effectiveness, saving manpower and material resources, and simplifying the operating process.

[0011] In some embodiments, mobile phase A is 0.02 mol / L potassium dihydrogen phosphate solution, the mobile phase A contains 0.5% triethylamine, the pH value is 3.8, the mobile phase B is acetonitrile, and the gradient elution program is 0-20 min, A is 80%-65%; 20-75 min, A is 65%-30%; 75-90 min, A is 30%; 90-91 min, A is 30%-80%; 91-110 min, A is 80%.

[0012] In some embodiments, the chromatographic column uses octadecylsilane bonded silica gel as a filler, the model is XB-C18, the specifications are 4.6 mm×150 mm, 5 μm.

[0013] In some embodiments, a sample of azilsartan levoamlodipine tablets is dissolved in methanol to obtain a test solution.

[0014] In some embodiments, in the test solution, the content of azilsartan is 1.6 mg / ml, and the content of levamlodipine is 0.2 mg / ml.

[0015] In some embodiments, the detection wavelength is 237 nm.

[0016] In some embodiments, the column temperature of the chromatography column is 30°C.

[0017] In some embodiments, the flow rate is 1.0 ml per minute.

[0018] In some embodiments, the injection volume is 10 μl.

[0019] The second aspect of the present invention provides a quality control method for Azilsartan Levoamlodipine Tablets, which is characterized by comprising: applying the above content to quantitatively determine the related substances of Azilsartan Levoamlodipine Tablets by self-control method.

[0020] Beneficial effects of the above technical solution:

[0021] The above technical scheme provides a method and application for simultaneously determining related substances of azilsartan and amlodipine. The related substances in azilsartan and amlodipine tablets are detected by high performance liquid chromatography, and the detection method is systematically optimized to determine the best detection method of liquid chromatography for 8 impurities in azilsartan and amlodipine tablets. It has the advantages of strong specificity, high sensitivity, safe test reagents, simple preparation and operation, and adaptability to most laboratories. Therefore, it is very suitable for the detection of related substances in azilsartan and amlodipine tablets, which is conducive to the quality control of azilsartan and amlodipine tablets, and has good practical application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention, and the exemplary embodiments of the present invention and their description are used to explain the present invention and do not constitute improper limitations on the present invention.

[0023] Figure 1 This is the full picture of the system suitability solution;

[0024] Figure 2 is the full picture of the sensitivity solution;

[0025] Figure 3 This is the full picture of the test solution;

[0026] Figure 4 This is the full picture of the control solution;

[0027] Figure 5 is the chromatogram of Azilsartan Levoamlodipine Tablets in Example 1;

[0028] Figure 6 is a chromatogram of the azilsartan impurity mixed solution in Comparative Example 1;

[0029] Figure 7 It is the chromatogram of levamlodipine besylate in Comparative Example 2;

[0030] Figure 8 This is the chromatogram of related substances in the Azilsartan raw material in Comparative Example 3. DETAILED DESCRIPTION

[0031] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0032]

[0033]

[0034] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, it will be described in detail below in conjunction with specific embodiments.

[0035] As mentioned above, currently only azilsartan-related substances or levamlodipine-related substances are controlled separately in the pharmacopoeias, reference documents and other patents of various countries.

[0036] Currently, there is no method that can simultaneously control the related substances of azilsartan and levoamlodipine.

[0037] In view of this, in the process of new drug research and development, the inventors invented a method that can simultaneously control azilsartan, levamlodipine and their related impurities in response to the need for drug quality control.

[0038] In another specific embodiment of the present invention, the method comprises:

[0039] Octadecyl silica gel was used as filler (XB-C18, 4.6 mm × 150 mm, 5 μm or a chromatographic column of equivalent performance); mobile phase A was 0.02 mol / L potassium dihydrogen phosphate solution (containing 0.5% triethylamine, pH adjusted to 3.8 with phosphoric acid), mobile phase B was acetonitrile, and the gradient elution program was 0-20 min, A was 80%-65%; 20-75 min, A was 65%-30%; 75-90 min, A was 30%; 90-91 min, A was 30%-80%; 91-110 min, A was 80%. The quantitative determination was carried out by the principal component self-control method.

[0040] The present invention systematically optimizes the above detection parameter conditions, and finally obtains a related substance detection method with the advantages of strong specificity, high sensitivity, safe test reagents, simple preparation and operation, and applicability to most laboratories.

[0041] In another specific embodiment of the present invention, there is provided application of the above-mentioned inspection method in azilsartan levoamlodipine tablets.

[0042] The application is specifically to determine and evaluate the detection amount of each impurity in azilsartan levoamlodipine tablets.

[0043] The present invention is further explained by the following examples, but they are not intended to limit the present invention. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. All raw materials used in the examples are commercially available unless otherwise specified.

[0044] The following embodiments are the process of method exploration.

[0045] Embodiment 1:

[0046] Chromatographic conditions:

[0047] Chromatographic column: octadecylsilane bonded silica gel as filler (XB-C18, 4.6 mm × 150 mm, 5 μm);

[0048] UV detector (detection wavelength: 237nm);

[0049] Mobile phase A: 0.02 mol / L potassium dihydrogen phosphate solution (containing 0.5% triethylamine, pH adjusted to 3.8 with phosphoric acid);

[0050] Mobile phase B: acetonitrile;

[0051] Injection volume: 10 μl;

[0052] Column temperature: 30°C;

[0053] Flow rate: 1.0ml / min.

[0054]

[0055] Test solution: Take 20 tablets of Azilsartan and Levoamlodipine, accurately weigh, grind, accurately weigh an appropriate amount of fine powder (equivalent to approximately 40 mg of Azilsartan and 5 mg of Levoamlodipine), place in a 25 ml volumetric flask, add methanol and ultrasonically dissolve the Azilsartan and Levoamlodipine, cool, dilute to the scale with methanol, shake well, centrifuge for 20 minutes (4000 revolutions per minute), and take the supernatant.

[0056] Accurately measure 10 μl of the test solution, inject it into the liquid chromatograph, and record the chromatogram. Figure 5 shown.

[0057] Because the filtration operation is time-consuming and laborious, the test results of different preparation methods are as follows.

[0058]

[0059] It can be seen from the chromatogram and test results that the main component and each impurity peak have good peak shapes, the separation degree meets the requirements, and each peak is detected without interference; the detection results of each impurity in different preparation methods are basically consistent.

[0060] The final chromatographic conditions were:

[0061] Chromatographic column: octadecylsilane bonded silica gel as filler (XB-C18, 4.6 mm × 150 mm, 5 μm);

[0062] UV detector (detection wavelength: 237nm);

[0063] Mobile phase A: 0.02 mol / L potassium dihydrogen phosphate solution (containing 0.5% triethylamine, pH adjusted to 3.8 with phosphoric acid);

[0064] Mobile phase B: acetonitrile;

[0065] Injection volume: 10 μl;

[0066] Column temperature: 30°C;

[0067] Flow rate: 1.0ml / min.

[0068]

[0069] Solution preparation:

[0070] Take 20 tablets of Azilsartan and Levoamlodipine tablets for test solution, accurately weigh, grind, accurately weigh an appropriate amount of fine powder (equivalent to approximately 40 mg of Azilsartan and 5 mg of Levoamlodipine), put it in a 25 ml volumetric flask, add methanol and ultrasonically dissolve the Azilsartan and Levoamlodipine, cool, dilute to the scale with methanol, shake well, centrifuge for 20 minutes (4000 revolutions per minute), and take the supernatant.

[0071] For the control solution, accurately measure an appropriate amount of the test solution, add solvent to dissolve it, and quantitatively dilute it to make a solution containing approximately 3.2 μg of azilsartan and 0.4 μg of levamlodipine per 1 ml.

[0072] If there are impurity peaks [excluding the benzenesulfonic acid peak] in the chromatogram of the test solution, the peak area of ​​the amlodipine impurity D peak multiplied by 2.0 shall not be greater than 2.5 times (0.5%) the main peak area of ​​levoamlodipine in the control solution, the peak areas of the azilsartan impurity A and azilsartan impurity B shall not be greater than 2.5 times (0.5%) the peak area of ​​azilsartan in the control solution, the peak area of ​​other individual impurities shall not be greater than the peak area of ​​azilsartan in the control solution (0.2%), and the total amount of impurities shall not exceed 2.0%.

[0073] Embodiment 2:

[0074] The methodological study of the above methods is as follows:

[0075] 1. Peak Positioning and Interference Test

[0076] Take appropriate amount of azilsartan, levamlodipine besylate, azilsartan impurity A, azilsartan impurity B, azilsartan impurity C, benzenesulfonic acid, amlodipine impurity D, deamination and cyclization impurity 1, deamination and cyclization impurity 2, and deamination and cyclization impurity 3 respectively, dissolve in solvent and dilute to make solutions containing approximately 8 μg of azilsartan, 1 μg of levamlodipine besylate, 8 μg of azilsartan impurity A, 8 μg of azilsartan impurity B, 8 μg of azilsartan impurity C, 1 μg of amlodipine impurity D, 1 μg of benzenesulfonic acid, 1 μg of deamination and cyclization impurity 1, 1 μg of deamination and cyclization impurity 2, and 1 μg of deamination and cyclization impurity 3 per 1 ml as respective peak positioning solutions.

[0077] Take about 450 mg of blank excipient, place it in a 25 mg volumetric bottle, add solvent to dissolve to the scale, shake well, and use it as the interference solution.

[0078] Take appropriate amounts of azilsartan, levamlodipine besylate, azilsartan impurity A, azilsartan impurity B, azilsartan impurity C, benzenesulfonic acid, amlodipine impurity D, deamination and cyclization impurity 1, deamination and cyclization impurity 2, deamination and cyclization impurity 3 and azilsartan levamlodipine tablet fine powder, add solvent to dissolve and dilute to prepare a solution containing approximately 8 μg of azilsartan, 1 μg of levamlodipine besylate, 8 μg of azilsartan impurity A, 8 μg of azilsartan impurity B, 8 μg of azilsartan impurity C, 1 μg of amlodipine impurity D, 1 μg of benzenesulfonic acid, 1 μg of deamination and cyclization impurity 1, 1 μg of deamination and cyclization impurity 2, 1 μg of deamination and cyclization impurity 3, 1.6 mg of azilsartan and 0.2 mg of levamlodipine per 1 ml as a mixed solution.

[0079] Accurately measure 10 μl of each of the solvent, the peak positioning solution, and the mixed solution, inject them into the liquid chromatograph, and record the chromatogram. The test results are shown in the following table:

[0080] Table 1 Related substances test of Azilsartan and Levoamlodipine Tablets – Peak location test results

[0081]

[0082] The test results show that the auxiliary materials do not peak, the impurities do not interfere with the peak of the main component, and the impurities in the mixed solution are well separated.

[0083] 2. Linearity test

[0084] Take appropriate amounts of Azilsartan reference substance, Azilsartan impurity A and Azilsartan impurity B, accurately weigh them, and prepare solutions containing 40 μg / ml of Azilsartan, Azilsartan impurity A and Azilsartan impurity B, respectively, as Azilsartan impurity linear stock solutions.

[0085] Take appropriate amounts of levamlodipine besylate reference substance and amlodipine impurity D, accurately weigh them, and prepare solutions containing 10 μg / ml of levamlodipine and amlodipine impurity D, respectively, as levamlodipine impurity linear stock solutions.

[0086] Accurately measure 0.1ml, 1ml, 2.5ml, 5ml, 6ml and 7.5ml of the impurity linear stock solution of azilsartan respectively, place them in different 50ml volumetric flasks, dilute to the scale with solvent, shake well, and use them as the concentration solutions for the linear test of azilsartan.

[0087] Accurately measure 0.5ml, 1ml, 2.5ml, 5ml, 6ml and 7.5ml of the linear stock solution of levoamlodipine impurity respectively, place them in different 50ml volumetric bottles, dilute to the scale with solvent, shake well, and use them as the concentration series solutions for the levoamlodipine linear test.

[0088] Accurately measure 10 μl, inject into liquid chromatograph, record the chromatogram, and perform linear regression of peak area with concentration.

[0089] The test results are shown in the following table:

[0090] Table 2 Linearity test results of known impurities research

[0091]

[0092]

[0093]

[0094] Table 3 Linearity test results of known impurities research

[0095]

[0096] The test results show that the linear relationship is good. The impurity D of amlodipine needs to be corrected with a correction factor of 2.0.

[0097] 3. Stability test of reference solution

[0098] Take appropriate amounts of Azilsartan Impurity A Reference Substance, Azilsartan Impurity B Reference Substance, and Amlodipine Impurity D Reference Substance, dissolve them in solvent and dilute them to make a solution containing approximately 8 μg of Azilsartan Impurity A, 8 μg of Azilsartan Impurity A, and 1 μg of Amlodipine Impurity D per 1 ml, as the reference substance solution.

[0099] The mixture was placed at room temperature for 72 hours. At 0 hour, 6 hours, 12 hours, 18 hours, 24 hours, 48 ​​hours and 72 hours, 10 μl was accurately measured and injected into a liquid chromatograph to record the chromatogram.

[0100] The test results are shown in the following table:

[0101] Table 4 Stability test results of known impurities in preparations

[0102]

[0103]

[0104] The test results show that the reference solution is basically stable when placed at room temperature for 72 hours.

[0105] 4. Test solution stability test

[0106] Take 20 tablets of Azilsartan and Levoamlodipine tablets for test solution, accurately weigh, grind, accurately weigh an appropriate amount of fine powder (equivalent to approximately 40 mg of Azilsartan and 5 mg of Levoamlodipine), put it in a 25 ml volumetric flask, add methanol and ultrasonically dissolve the Azilsartan and Levoamlodipine, cool, dilute to the scale with methanol, shake well, centrifuge for 20 minutes (4000 revolutions per minute), and take the supernatant.

[0107] The mixture was placed at room temperature for 72 hours. At 0 hour, 6 hours, 12 hours, 18 hours, 24 hours, 48 ​​hours and 72 hours, 10 μl was accurately measured and injected into a liquid chromatograph to record the chromatogram.

[0108] The test results are shown in the following table:

[0109] Table 5 Stability test results - test solution

[0110]

[0111]

[0112] The test results show that the test solution is basically stable at room temperature for 72 hours.

[0113] 5. Accuracy test

[0114] Blank solvent: Take an appropriate amount of methanol as the blank solvent.

[0115] Amlodipine impurity D stock solution: Take about 2.4 mg of amlodipine impurity D reference substance, accurately weigh it, place it in a 20 ml volumetric flask, add solvent to dissolve and dilute to the scale, and shake well.

[0116] Impurity mixed stock solution: Take about 2 mg each of Azilsartan Impurity A reference substance and Azilsartan Impurity B reference substance, accurately weigh, place in the same 50 ml volumetric flask, add appropriate amount of solvent to dissolve, accurately add 2.5 ml of Amlodipine Impurity D stock solution, dilute to the scale with solvent, and shake well.

[0117] Reference solution: Accurately measure 5 ml of the impurity mixed stock solution, place it in a 25 ml volumetric flask, dilute to the scale with solvent, and shake well.

[0118] Test solution: Take 20 tablets of this product, accurately weigh, grind, accurately weigh about 500 mg of fine powder (equivalent to 40 mg of azilsartan and 5 mg of levamlodipine), put it in a 25 ml volumetric flask, add solvent to dissolve and dilute to the scale, shake well, centrifuge for 20 minutes (4000 revolutions per minute), and take the supernatant.

[0119] Accuracy solution: Accurately weigh about 500 mg of fine powder of this product (equivalent to approximately 40 mg of azilsartan and 5 mg of levamlodipine), place in a 25 ml volumetric flask, accurately add 0.5 ml, 2 ml, 5 ml, and 10 ml of the impurity mixed stock solution, add an appropriate amount of solvent to dissolve azilsartan, dilute to the scale with solvent, shake well, centrifuge for 20 minutes (4000 revolutions per minute), and take the supernatant as 0.05%, 0.2%, 0.5%, and 1.0% accuracy solutions, respectively.

[0120] Accurately measure 10 μl of blank solvent, test solution and the above solution, respectively, and inject them into the liquid chromatograph, record the chromatogram, and calculate the recovery rate by peak area according to the external standard method.

[0121] Table 6 Accuracy test results-1

[0122]

[0123] Table 7 Accuracy test results-2

[0124]

[0125]

[0126] The test results show that the average recovery rates of the impurities determined by the established method are all within the range of 90% to 108%, the relative standard deviations meet the requirements, the recovery rates are good, and the accuracy is high.

[0127] 6. Inspection

[0128] The above method was used to examine the inspection of related substances in Azilsartan Levoamlodipine Tablets. The test results are shown in the following table:

[0129] Table 8 Related substance inspection test results - Homemade products

[0130] batch number 24022501 24022502 24022801 Azilsartan Impurity A(%) 0.07 0.07 0.07 Amlodipine Impurity D(%) 0.14 0.14 0.13 Azilsartan Impurity A(%) 0.04 0.04 0.04 Other largest impurities (%) 0.04 0.04 0.04 Other total impurities (%) 0.34 0.35 0.33

[0131] The test results show that the detection results of relevant substances in each batch of samples are good.

[0132] In summary, the method provided in the embodiment for detecting related substances in azilsartan levoamlodipine tablets has good linearity, specificity, accuracy and stability, strong practicality, and is simpler and more efficient in operation.

[0133] Comparative Example 1

[0134] Take appropriate amounts of azilsartan impurities A, B, C, D, E, F, G, H, I, deamination and cyclization impurity 1, deamination and cyclization impurity 2, and deamination and cyclization impurity 3, accurately weigh them, add methanol to dissolve and dilute them to prepare a solution containing approximately 10 μg of each impurity per 1 ml, as the azilsartan impurity mixed solution.

[0135] Take appropriate amounts of amlodipine impurities A, B, D, E, F, G, and H, accurately weigh them, add methanol to dissolve and dilute them to make a solution containing about 10 μg of each impurity per 1 ml, as the levoamlodipine impurity mixed solution.

[0136] Take an appropriate amount of azilsartan raw material, add methanol to dissolve and dilute to make a solution containing about 1 mg per 1 ml, which is used as the azilsartan solution.

[0137] Take an appropriate amount of levoamlodipine besylate raw material, add methanol to dissolve and dilute to prepare a solution containing about 1 mg of amlodipine per 1 ml, which is used as the levoamlodipine solution.

[0138] Take appropriate amounts of azilsartan raw material, levamlodipine besylate raw material and various impurities, add methanol to dissolve and dilute to prepare a solution containing approximately 4 mg of azilsartan, 0.7 mg of levamlodipine and 1 μg of various impurities per 1 ml, as a mixed solution.

[0139] Chromatographic conditions: Refer to the mobile phase system of the related substances in the self-developed Azilsartan tablets project of our company. Mobile phase A: 20mmol / L potassium dihydrogen phosphate solution (pH value adjusted to 3.0 with phosphoric acid); mobile phase B: acetonitrile; chromatographic column: XB-C18 (4.6×150mm, 5μm); column temperature: 30℃; flow rate: 1.0ml / min; wavelength: 238nm; solvent: methanol; gradient conditions are shown in the following table.

[0140]

[0141] This method has multiple impurities overlapped, the separation of impurities is not ideal, and it is not possible to simultaneously detect azilsartan and levamlodipine related impurities. The chromatogram is shown in Figure 6 shown.

[0142] Comparative Example 2

[0143] Take an appropriate amount of this product, add mobile phase to dissolve and dilute to make a solution containing about 1 mg of levoamlodipine per 1 ml, as the test solution; accurately measure an appropriate amount of the test solution, quantitatively dilute it with mobile phase to make a solution containing about 3 μg of levoamlodipine per 1 ml, as the control solution.

[0144] According to the high performance liquid chromatography method (Chinese Pharmacopoeia 2020 Edition Part IV General Rules 0512), octadecylsilane bonded silica gel is used as the filler (Phenomenex Luna C18, 4.6mm×250mm, 5μm or a chromatographic column with equivalent performance); methanol-acetonitrile-0.7% triethylamine solution (take 7.0ml of triethylamine, dilute to 1000ml with water, and adjust the pH to 3.0±0.1 with phosphoric acid) (35:15:50) is used as the mobile phase; the detection wavelength is 237nm; the injection volume is 20μl.

[0145] Using the method under the inspection item of amlodipine besylate provided in Part II of the 2020 edition of the Chinese Pharmacopoeia, the peak of azilsartan is flat in the chromatogram, and multiple impurities are poorly separated, such as Figure 7 shown.

[0146] Comparative Example 3

[0147] Reference patent CN 105628824 A A method for determining related substances in azilsartan raw materials by high performance liquid chromatography: the stationary phase of the high performance liquid chromatograph is octadecyl bonded silica gel, the mobile phase A is 0.1% phosphoric acid aqueous solution: acetonitrile = 80:20, the mobile phase B is 0.1% phosphoric acid aqueous solution: acetonitrile = 20:80, the column temperature is 35°C, the detection wavelength is 210nm, and the test solution is prepared with 50% acetonitrile to contain 0.5mg azilsartan, and linear gradient elution is performed according to the following table; the flow rate is 1.0ml per minute; the injection volume is 20μl.

[0148]

[0149]

[0150] This method does not separate multiple impurities well, which affects the detection of related substances, such as Figure 8 shown.

[0151] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for detecting related substances in Azilsartan Levoamlodipine Tablets, characterized in that: include: HPLC was used to quantitatively detect impurities in azilsartan-levoamlodipine tablets; Among them, the impurities are azilsartan impurity A, azilsartan impurity B, azilsartan impurity C, benzenesulfonic acid, amlodipine impurity D, deamination cyclization impurity 1, deamination cyclization impurity 2, and deamination cyclization impurity 3.

2. The method for detecting related substances in Azilsartan Levoamlodipine Tablets according to claim 1, characterized in that: The mobile phase A is a 0.02 mol / L potassium dihydrogen phosphate solution, which contains 0.5% triethylamine and has a pH value of 3.

8. The mobile phase B is acetonitrile, and the gradient elution program is 0-20 min, A is 80%-65%; 20-75 min, A is 65%-30%; 75-90 min, A is 30%; 90-91 min, A is 30%-80%; 91-110 min, A is 80%.

3. The method for detecting related substances in Azilsartan Levoamlodipine Tablets according to claim 1, characterized in that: The chromatographic column uses octadecylsilane bonded silica gel as filler, model XB-C18, specification 4.6mm×150mm, 5μm.

4. The method for detecting related substances in Azilsartan Levoamlodipine Tablets according to claim 1, characterized in that: Azilsartan / amlodipine tablet sample was dissolved in methanol to obtain a test solution.

5. The method for detecting related substances in Azilsartan Levoamlodipine Tablets according to claim 4, characterized in that: In the test solution, the content of azilsartan is 1.6 mg / ml, and the content of levamlodipine is 0.2 mg / ml.

6. The method for detecting related substances in Azilsartan Levoamlodipine Tablets according to claim 1, characterized in that: The detection wavelength is 237 nm.

7. The method for detecting related substances in Azilsartan Levoamlodipine Tablets according to claim 1, characterized in that: The column temperature was 30°C.

8. The method for detecting related substances in Azilsartan Levoamlodipine Tablets according to claim 1, characterized in that: The flow rate was 1.0 ml per minute.

9. The method for detecting related substances in Azilsartan Levoamlodipine Tablets according to claim 1, characterized in that: The injection volume was 10 μl.

10. A quality control method for Azilsartan Levoamlodipine Tablets, characterized in that: The invention comprises the application of any one of claims 1 to 9, wherein the self-control method is used to quantitatively determine the related substances of azilsartan levamlodipine tablets.

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