A method for testing related substances in Olmesartan Medoxomil Hydrochlorothiazide Tablets

Abstract

The invention belongs to the technical field of drug analysis, and specifically relates to a method for detecting related substances of Olmesartan Medoxomil Hydrochlorothiazide Tablets. In order to solve the detection problem of related substances of Olmesartan Medoxomil Hydrochlorothiazide Tablets, a convenient, efficient and accurate detection method is provided, which can detect the content of related substances of Olmesartan Medoxomil Hydrochlorothiazide Tablets, thereby effectively ensuring the safety of medication and facilitating the quality control of Olmesartan Medoxomil Hydrochlorothiazide Tablets. The method is convenient, efficient and accurate, and fully complies with the guiding principles of method verification of the Chinese Pharmacopoeia in terms of system applicability, repeatability, specificity and accuracy, and can be used for the quality control of Olmesartan Medoxomil Hydrochlorothiazide Tablets.

Description

Technical Field

[0001] The invention belongs to the technical field of drug analysis, and particularly relates to a method for detecting related substances in Olmesartan Medoxomil and Hydrochlorothiazide Tablets. Background Art

[0002] Olmesartan medoxomil hydrochlorothiazide tablets were approved for marketing in my country in 2010 as a second-line drug for the treatment of hypertension. The main active ingredients are olmesartan medoxomil and hydrochlorothiazide. Olmesartan medoxomil is hydrolyzed into the active ingredient olmesartan in the gastrointestinal tract and exerts a hypotensive effect; hydrochlorothiazide increases the excretion of sodium, potassium, chloride ions and water, thereby reducing blood volume and enhancing the hypotensive effect of olmesartan medoxomil.

[0003] In the current standard of Olmesartan medoxomil hydrochlorothiazide tablets, high performance liquid chromatography is used to determine the related substances in the drug, but the sensitivity and separation of this method are relatively poor. Currently, there are few literature reports on methods for determining the content of related substances, and the determination methods still have deficiencies. For example, Zhao Jianfeng-HPLC determination of the content and related substances of Olmesartan medoxomil hydrochlorothiazide tablets. Although a related substance analysis method for this compound preparation was established, only two related substances were discussed, and no methodological verification was performed on the quantitative method of the related substances.

[0004] The present invention discloses a method for determining related substances of Olmesartan Medoxomil Hydrochlorothiazide Tablets by using a high performance liquid phase method, which can detect 7 related substances in Olmesartan Medoxomil Hydrochlorothiazide Tablets. According to the research on the process impurities of Olmesartan Medoxomil Hydrochlorothiazide Tablets, the present inventors found 7 related substances in Olmesartan Medoxomil Hydrochlorothiazide Tablets, and the impurities and structural formulas thereof are as follows: Benzothiadiazine related substance A: , chlorothiazide: , Olmesartan: , Hydrochlorothiazide dimer: , olefin impurities: , Olmesartan dimer: , Olmesartan Impurity 21: .

[0005] Currently, there is no public detection method that can effectively separate the above-mentioned 7 impurities, let alone accurately quantify these potential impurities, which poses a great risk to the safety of Olmesartan Medoxomil Hydrochlorothiazide Tablets.

[0006] The present invention solves the problem of detecting related substances of Olmesartan medoxomil hydrochlorothiazide tablets and provides a convenient, efficient and accurate detection method. The method can detect the related substances of Olmesartan medoxomil hydrochlorothiazide tablets, thereby effectively ensuring the safety of medication and facilitating the quality control of Olmesartan medoxomil hydrochlorothiazide tablets. Summary of the invention

[0007] The invention provides a detection method for determining related substances of Olmesartan Medoxomil Hydrochlorothiazide Tablets by adopting high performance liquid chromatography. In order to solve the detection problem of related substances of Olmesartan Medoxomil Hydrochlorothiazide Tablets, a convenient, efficient and accurate detection method is provided. The method can detect the content of related substances in Olmesartan Medoxomil Hydrochlorothiazide Tablets, thereby effectively ensuring the safety of medication and facilitating the quality control of Olmesartan Medoxomil Hydrochlorothiazide Tablets. The method is convenient, efficient and accurate, and fully complies with the guiding principles of method verification of the Chinese Pharmacopoeia in terms of system applicability, repeatability, specificity and accuracy, and can be used for the quality control of Olmesartan Medoxomil Hydrochlorothiazide Tablets.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A method for testing related substances in Olmesartan Medoxomil Hydrochlorothiazide Tablets, the detection method comprising the following steps:

[0010] (1) Prepare solutions including blank solution, sensitivity solution, reference solution and test solution.

[0011] (2) Determination method: Olmesartan medoxomil hydrochlorothiazide tablets related substances were determined by high performance liquid chromatography. After the system was stable, blank solution, sensitivity solution, reference solution and test solution were added respectively, and the chromatogram was recorded.

[0012] The chromatographic conditions are as follows: chromatographic column: octylsilane bonded silica gel as filler, detection wavelength: 250nm; flow rate: 1.0±0.1ml / min; column temperature: 25±2℃; injection volume: 5μl, injector temperature: 5℃, mobile phase is phosphoric acid solution: acetonitrile system, and gradient elution is used.

[0013] Furthermore, the blank solution is 70% acetonitrile; the mobile phase is: mobile phase A: transfer 1.0 ml of phosphoric acid into 1000 ml of ultrapure water, mix well, and degas by ultrasonication; mobile phase B: acetonitrile; the reference solution: take an appropriate amount of Olmesartan Medoxomil reference and hydrochlorothiazide reference and place them in a volumetric bottle, add blank solution to dilute to the scale, and shake well; the sensitivity solution: take an appropriate amount of reference solution, place it in a volumetric bottle, add blank solution to dilute to the scale, and shake well; the test solution: take an appropriate amount of the test sample, accurately weigh it, place it in a volumetric bottle, and add diluent to dilute to the scale; the chromatographic column is Waters, SunFire® C8 4.6mm×100mm, 3.5μm. or a chromatographic column with equivalent performance.

[0014] Further, the gradient elution is:

[0015]

[0016] The detection method of the related substances of Olmesartan Medoxomil Hydrochlorothiazide Tablets also includes method validation before the detection, and the method validation is based on the chromatographic conditions of the formal detection, and the measurement results are:

[0017]

[0018] The invention discloses a method for detecting related substances of Olmesartan Medoxomil Hydrochlorothiazide Tablets, and provides a convenient, efficient and accurate detection method to solve the detection problem of related substances of Olmesartan Medoxomil Hydrochlorothiazide Tablets. The method can detect the content of related substances in Olmesartan Medoxomil Hydrochlorothiazide Tablets, thereby effectively ensuring the safety of medication. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the blank solution spectrum of related substances of Olmesartan Medoxomil Hydrochlorothiazide Tablets

[0020] Figure 2 Olmesartan Medoxomil Hydrochlorothiazide Tablets Related Substances Test Solution Spectrum

[0021] Figure 3 Olmesartan Medoxomil Hydrochlorothiazide Tablets Related Substance Reference Solution Spectrum

[0022] Figure 4 Selective solution spectrum of related substances in Olmesartan Medoxomil and Hydrochlorothiazide Tablets DETAILED DESCRIPTION

[0023] The present invention is further illustrated by the following examples, but are not intended to limit the present invention.

[0024] Embodiment 1:

[0025] (1) Preparation of solution:

[0026] Blank solution (diluent): 70% acetonitrile.

[0027] Blank excipient solution: Take 243 mg of the prescribed amount of mixed excipients (approximately equivalent to the amount of excipients contained in 28 mg of Olmesartan Medoxomil sample powder), accurately weigh, place in a 50 ml volumetric flask, add an appropriate amount of diluent, dissolve by ultrasonic, dilute to the scale with diluent, shake well, and centrifuge to obtain.

[0028] System suitability solution A (Benzothiadiazine related substance A stock solution ①): Take about 5.0 mg of Benzothiadiazine related substance A reference substance, accurately weigh it, place it in a 25 ml volumetric flask, add diluent, dissolve it by ultrasonication, dilute to the scale, and shake well. (Concentration: 200 µg / ml)

[0029] System suitability solution B (chlorothiazide stock solution ①): Take about 5.0 mg of chlorothiazide reference substance, accurately weigh it, place it in a 25 ml volumetric bottle, add diluent, dissolve it by ultrasonic, dilute to the scale, and shake well. (Concentration: 200 µg / ml)

[0030] System suitability solution: Take about 22 mg of Olmesartan Medoxomil reference substance and 7 mg of Hydrochlorothiazide reference substance, weigh accurately, place in a 20 ml volumetric flask, add appropriate amount of diluent and ultrasonically dissolve, accurately add 0.4 ml of System Suitability Solution A and 0.2 ml of System Suitability Solution B, add diluent to dilute to the scale, and shake well. (Olmesartan Medoxomil: 1.1 mg / ml, Hydrochlorothiazide: 0.35 mg / ml, Chlorothiazide: 2 µg / ml, Benzothiadiazine Related Substance A: 4 µg / ml)

[0031] Preparation of Olmesartan medoxomil stock solution and hydrochlorothiazide stock solution: Take Olmesartan medoxomil reference substance and hydrochlorothiazide reference substance and place them in different volumetric bottles respectively, add diluent to dilute to the scale, and prepare Olmesartan medoxomil stock solution concentration: 140μg / ml, hydrochlorothiazide stock solution concentration: 90μg / ml.

[0032] Reference solution: Take the Olmesartan Medoxomil stock solution and the Hydrochlorothiazide stock solution and place them in the same volumetric flask, add diluent to prepare the concentrations: Olmesartan Medoxomil: 2.8 μg / ml, Hydrochlorothiazide: 1.8 μg / ml.

[0033] Sensitivity solution: Place the reference solution in a volumetric flask and add diluent to prepare the concentrations: Olmesartan medoxomil: 0.56 μg / ml, Hydrochlorothiazide: 0.36 μg / ml.

[0034] Test solution: Take no less than 20 tablets, weigh, calculate the average tablet weight, grind, take about 290 mg of sample powder (equivalent to 28 mg of Olmesartan Medoxomil), accurately weigh, place in a 50 ml volumetric flask, add diluent to 70% of the volumetric flask, shake and ultrasonically dissolve if necessary, dilute to the scale with diluent, shake well, filter through a 0.45 µm filter membrane, and take the filtrate (Olmesartan Medoxomil: 0.56 mg / ml, Hydrochlorothiazide: 0.35 mg / ml).

[0035] Preparation of hydrochlorothiazide dimer stock solution ①, Olmesartan stock solution ①, olefin impurity stock solution ①, Olmesartan dimer stock solution ①, and Olmesartan impurity 21 stock solution ①: respectively place hydrochlorothiazide dimer reference substance, Olmesartan reference substance, olefin impurity reference substance, Olmesartan dimer reference substance and Olmesartan impurity 21 reference substance in different volumetric flasks, add diluent and ultrasonically dissolve them, then dilute to the scale to prepare hydrochlorothiazide dimer stock solution ①: 200µg / ml, Olmesartan stock solution ①: 1450µg / ml, olefin impurity stock solution ①: 350µg / ml, Olmesartan dimer stock solution ①: 300µg / ml, and Olmesartan impurity 21 stock solution ①: 300µg / ml.

[0036] Preparation of hydrochlorothiazide dimer stock solution ②, Olmesartan stock solution ②, olefin impurity stock solution ②, Olmesartan dimer stock solution ②, Olmesartan impurity 21 stock solution ②, benzothiadiazine related substance A stock solution ②, chlorothiazide stock solution ②: Take hydrochlorothiazide dimer stock solution ①, Olmesartan stock solution ①, olefin impurity stock solution ①, Olmesartan dimer stock solution ①, Olmesartan impurity 21 stock solution ①, benzothiadiazine related substance A stock solution ①, chlorothiazide stock solution ② respectively. Solution ① was placed in different volumetric bottles, diluted to the mark after adding diluent for ultrasonic dissolution, and prepared into hydrochlorothiazide dimer stock solution ②: 36µg / ml, olmesartan stock solution ②: 232µg / ml, olefin impurity stock solution ②: 56µg / ml, olmesartan dimer stock solution ②: 18µg / ml, olmesartan impurity 21 stock solution ②: 18µg / ml, benzothiadiazine related substance A stock solution ②: 60μg / ml, chlorothiazide stock solution ②: 12μg / ml.

[0037] Prepare hydrochlorothiazide dimer localization solution, olmesartan localization solution, olefin impurity localization solution, olmesartan dimer localization solution, olmesartan impurity 21 localization solution, olmesartan medoxomil localization solution, chlorothiazide localization solution, and benzothiadiazine related substance A localization solution: take hydrochlorothiazide dimer stock solution ②, olmesartan stock solution ②, olefin impurity stock solution ②, olmesartan dimer stock solution ②, olmesartan impurity 21 stock solution ②, olmesartan medoxomil stock solution, chlorothiazide stock solution ②, and benzothiadiazine related substance A stock solution ② respectively. In different volumetric flasks, add diluent and ultrasonically dissolve, then dilute to the scale to prepare hydrochlorothiazide dimer localizing solution: 2.16µg / ml, olmesartan localizing solution: 14µg / ml, olefin impurity localizing solution: 3.36µg / ml, olmesartan dimer localizing solution: 1.08µg / ml, olmesartan impurity 21 localizing solution: 1.1µg / ml, olmesartan medoxomil localizing solution: 2.8μg / ml, chlorothiazide localizing solution: 0.72μg / ml, benzothiadiazine-related substance A localizing solution: 3.6μg / ml.

[0038] Mixed impurity reference substance stock solution: accurately measure 3.0ml of chlorothiazide stock solution①, 15.0ml of benzothiadiazine related substance A stock solution①, 9.0ml of hydrochlorothiazide dimer stock solution①, 8.0ml of olmesartan stock solution①, 8.0ml of olefin stock solution①, 3.0ml of olmesartan impurity 21 stock solution①, and 3.0ml of olmesartan impurity 21 stock solution①, place in a 50ml volumetric flask, add diluent to dissolve and dilute to the scale, shake well, and obtain. (Chlorothiazide: 12μg / ml, benzothiadiazine related substance A: 60μg / ml, hydrochlorothiazide dimer: 36μg / ml, olmesartan: 232μg / ml, olefin: 56μg / ml, olmesartan dimer: 18μg / ml, olmesartan impurity 21: 18μg / ml)

[0039] Mixed impurity reference substance stock solution ①: Accurately measure 3.0ml of chlorothiazide stock solution ①, 15.0ml of benzothiadiazine related substance A stock solution ①, 9.0ml of hydrochlorothiazide dimer stock solution ①, 8.0ml of olmesartan stock solution ①, 8.0ml of olefin stock solution ①, and 3.0ml of olmesartan dimer stock solution ①, place in a 50ml volumetric flask, add diluent to dilute to the scale, shake well, and obtain. (Chlorothiazide: 12μg / ml, benzothiadiazine related substance A: 60μg / ml, hydrochlorothiazide dimer: 36μg / ml, olmesartan: 232μg / ml, olefin: 56μg / ml, 18μg / ml of olmesartan dimer)

[0040] Selective solution: Take no less than 20 tablets of sample, weigh them, calculate the average tablet weight, grind them, take about 290 mg of sample powder (equivalent to 28 mg of Olmesartan Medoxomil), accurately weigh them, put them in a 50 ml volumetric flask, then accurately add 3.0 ml of mixed impurity reference stock solution, add about 30 ml of diluent, shake and ultrasonically dissolve them if necessary, dilute to the scale with diluent, shake well, centrifuge (8000 rpm for 5 minutes), and take the supernatant.

[0041] Test solution (raw material): Take 28 mg of Olmesartan Medoxomil API and 17.5 mg of Hydrochlorothiazide API, accurately weigh, place in a 50 ml volumetric flask, add diluent to 70% of the volumetric flask, shake and sonicate to dissolve if necessary, add diluent to dilute to the scale, shake well, and obtain.

[0042] Test solution (preparation): Same as test solution

[0043] Selective solution: Take no less than 20 tablets of sample, weigh them, calculate the average tablet weight, grind them, take about 290 mg of sample powder (equivalent to 28 mg of olmesartan medoxomil), accurately weigh them, put them in a 50 ml volumetric flask, then accurately add 3.0 ml of mixed impurity reference substance stock solution①, add diluent to 70% of the volumetric flask, shake and ultrasonically dissolve them if necessary, dilute to the scale with diluent, shake well, filter through a 0.45 µm filter membrane, and take the filtrate.

[0044] Test solution (Olmesartan Medoxomil), test solution (Hydrochlorothiazide): Take 28 mg of Olmesartan Medoxomil API and 17.5 mg of Hydrochlorothiazide API, accurately weigh them, and place them in different 50 ml volumetric flasks respectively. Add diluent to 70% of the volumetric flask, shake and sonicate to dissolve if necessary, add diluent to dilute to the scale, shake well, and obtain.

[0045] Test solution (Olmesartan Medoxomil + blank excipients), test solution (Hydrochlorothiazide + blank excipients): Take 28 mg of Olmesartan Medoxomil API + 243 mg of blank excipients, and 17.5 mg of Hydrochlorothiazide API + 243 mg of blank excipients, accurately weigh, and place in two different 50 ml volumetric flasks respectively, add diluent to 70% of the volumetric flask, shake and ultrasonically dissolve if necessary, add diluent to dilute to the scale, shake well, filter through a 0.45 µm filter membrane, and take the filtrate.

[0046] Acid degradation test solution (preparation): Take no less than 20 samples, accurately weigh, grind, take about 290 mg of this product (equivalent to 28 mg of olmesartan medoxomil) accurately weighed, put into a 50 ml volumetric flask, add 5 ml of 0.1 mol / L hydrochloric acid solution, shake well to fully moisten, let stand at room temperature for 10 min, add 5 ml of 0.1 mol / L sodium hydroxide solution to neutralize, then add diluent to dissolve and dilute to the scale, shake well, filter through a 0.45 µm filter membrane, and take the filtrate; prepare acid blank solution, acid degradation blank excipient solution, acid degradation test solution (olmesartan medoxomil), acid degradation test solution (hydrochlorothiazide), acid degradation test solution (hydrochlorothiazide + blank excipient), acid degradation test solution (olmesartan medoxomil + blank excipient) in the same way.

[0047] Alkali degradation test solution (preparation): Take no less than 20 samples, accurately weigh, grind, take about 290 mg of this product (equivalent to 28 mg of olmesartan medoxomil) accurately weighed, put into a 50 ml volumetric flask, add 5 ml of 0.01 mol / L sodium hydroxide, shake well to fully moisten, let stand at room temperature for 10 min, add 5 ml of 0.01 mol / L hydrochloric acid solution to neutralize, then add diluent to dissolve and dilute to the scale, shake well, filter through a 0.45 µm filter membrane, and take the filtrate; prepare alkali blank solution, alkali degradation blank excipient solution, alkali degradation test solution (olmesartan medoxomil), alkali degradation test solution (hydrochlorothiazide), alkali degradation test solution (hydrochlorothiazide + blank excipient), alkali degradation test solution (olmesartan medoxomil + blank excipient) in the same way.

[0048] Oxidative degradation test solution (preparation): Take no less than 20 samples, accurately weigh, grind, take about 290 mg of this product (equivalent to 28 mg of olmesartan medoxomil) accurately weigh, place in a 50 ml volumetric flask, add 5 ml of 10% hydrogen peroxide solution, shake well to fully moisten, let stand at room temperature for 2 hours, add diluent to dissolve and dilute to the scale, shake well, filter through a 0.45 µm filter membrane, and take the filtrate; prepare oxidation blank solution, oxidation degradation blank excipient solution, oxidation degradation test solution (olmesartan medoxomil), oxidation degradation test solution (hydrochlorothiazide), oxidation degradation test solution (hydrochlorothiazide + blank excipient), and oxidation degradation test solution (olmesartan medoxomil + blank excipient) in the same way.

[0049] High temperature degradation test solution (preparation): Take 20 pieces of samples that have been placed in an oven at 60°C for more than 15 days (precisely weighed), grind them into powder, accurately weigh 290 mg (equivalent to 28 mg of olmesartan medoxomil), put them in a 50 ml volumetric flask, add diluent to dissolve and dilute to the scale, shake well, filter through a 0.45µm filter membrane, and take the filtrate; prepare high temperature degradation blank excipient solution, high temperature degradation test solution (olmesartan medoxomil), high temperature degradation test solution (hydrochlorothiazide), high temperature degradation test solution (hydrochlorothiazide + blank excipient), and high temperature degradation test solution (olmesartan medoxomil + blank excipient) in the same way.

[0050] Photodegradation test solution (preparation): Take a strong light irradiation test box (4500±500Lux, 90μw / cm 2 ) for more than 15 days, grind 20 tablets (precisely weighed) of the sample, accurately weigh 290 mg (equivalent to 28 mg of olmesartan medoxomil), put it in a 50 ml volumetric flask, add diluent to dissolve and dilute to the scale, shake well, filter through a 0.45 µm filter membrane, and take the filtrate; prepare the photodegradable blank excipient solution, photodegradable test solution (olmesartan medoxomil), photodegradable test solution (hydrochlorothiazide), photodegradable test solution (hydrochlorothiazide + blank excipient), and photodegradable test solution (olmesartan medoxomil + blank excipient) in the same way.

[0051] The chromatographic conditions are as follows:

[0052] Determination method:

[0053] After the system is stable, inject 1 to 3 injections of blank solution, 1 injection of system suitability solution, 1 injection of sensitivity solution, 6 injections of reference solution, and 1 injection of test solution. Inject reference solution for back calibration at the 12-injection interval and at the end of the sequence.

[0054] (1) Calculate the content of benzothiadiazine related substance A, chlorothiazide and hydrochlorothiazide dimer:

[0055] Impurity content (%) = %

[0056] A R —Average peak area of ​​hydrochlorothiazide in reference solution; M R —The amount of hydrochlorothiazide reference substance sampled (mg);

[0057] C R -Content of hydrochlorothiazide reference substance; D R —Dilution multiple of reference solution;

[0058] D S —Dilution multiple of the test solution;W - average tablet weight (mg);

[0059] A S - The peak area of ​​benzothiadiazine related substance A or chlorothiazide or hydrochlorothiazide dimer in the test solution;

[0060] M S —The sampling amount of the test product (mg); Q —Specification of hydrochlorothiazide (mg);

[0061] F —Relative response factor

[0062] (2) Calculation of the contents of Olmesartan, olefin impurities, Olmesartan dimers and other degradation impurities

[0063] Impurity content (%) = %

[0064] A R —Average peak area of ​​olmesartan medoxomil in reference solution;

[0065] C R — Olmesartan Medoxomil reference substance content; D R —Dilution multiple of reference solution;

[0066] D S —Dilution multiple of the test solution; M S —The sampling amount of the test product (mg);

[0067] A S —The peak area of ​​olmesartan, olmesartan dimer or olefin impurity in the test solution;

[0068] W - average tablet weight (mg); Q —Olmesartan Medoxomil specifications (mg);

[0069] F —Relative response factor M R - Olmesartan medoxomil reference substance sampling amount (mg);

[0070] (3) When calculating other impurities, the relative response factors are all 1.00.

[0071] (4) Total degradation impurities = benzothiadiazine related substance A content + chlorothiazide content + hydrochlorothiazide dimer content + olmesartan content + olefin impurities content + olmesartan dimer content + total amount of other degradation impurities

[0072] Example 2: System Applicability

[0073] System suitability is determined by examining the RSD of the peak area of ​​the reference solution. System suitability must be tested at the beginning of each test. Tests can only be carried out after the system suitability has been passed. At the end of the sequence, a reference solution must be added for return calibration.

[0074] Example 3: Specificity

[0075] The specificity study of the method examined peak identification and selectivity. The separation degree between benzothiadiazine related substance A and chlorothiazide in the test solution and selective solution was ≥2.0; the separation degree between chlorothiazide and hydrochlorothiazide was ≥1.5, the separation degree between the main peak and each known impurity peak and adjacent peaks was ≥1.5, the separation degree between olmesartan impurity 21 and adjacent peaks in the selective solution was ≥1.5, and the peak purity factor of the main peak should meet the acceptable standard.

[0076] Example 4: Strong degradation test

[0077] The strong degradation test is to destroy the sample under various strong environmental factors, the purpose is to evaluate the effectiveness and applicability of the analysis method by examining the separation of the sample's degradation products and main peaks and known impurities. At the same time, it provides a reference for the packaging, transportation and storage conditions of the preparation.

[0078] Example 5: Membrane adsorption

[0079] Investigate whether filtration through the membrane has any impact on the measurement results.

[0080] Example 6: Limit of Quantitation, Limit of Detection

[0081] The limit of quantification is obtained by measuring the signal-to-noise ratio S / N, requiring the limit of quantification concentration ≤ 0.05%, S / N ≥ 10; the signal-to-noise ratio of the detection limit S / N ≥ 3. At the limit of quantification concentration, 6 solutions are repeatedly examined, and the RSD of the peak area in the chromatogram obtained 6 times is required to be ≤ 10% to confirm that the limit of quantification determination result has a certain degree of precision.

[0082]

[0083] Example 7: Linear

[0084] For each component, take 6 concentrations within the concentration limit range of LOQ ~ 200% and prepare 6 test solutions. Perform linear regression on the concentration and peak area, which should be linear.

[0085] Example 8: Precision

[0086] Repeatability: Repeatability is achieved by measuring 6 test sample solutions, and the difference between the 6 measurement results is required to meet the acceptance criteria.

[0087]

[0088] Intermediate precision

[0089] Intermediate precision is achieved by another inspector measuring 6 test solutions at different times and with different instruments, and the difference between the measurement results of the 6 test solutions meets the acceptance criteria. Repeatability requires that the difference between the 6 measurement results, a total of 12 measurement results, meets the acceptance criteria.

[0090] Accuracy: Accuracy is achieved by measuring the recovery between the measured and theoretical concentrations of known impurities at different concentration levels, and the recovery is required to meet the acceptance criteria.

[0091] Durability:

[0092] The changes in the test results of the reference solution, reference stock solution and test solution at room temperature and 5°C during the test period were examined to provide a basis for the placement conditions of the test solution during the test. The durability examination included the flow rate, column temperature and replacement of the chromatographic column in the chromatographic conditions and compared them with normal conditions.

[0093]

[0094] Minor changes in chromatographic conditions

[0095] Durability was tested by examining four factors: chromatographic conditions: flow rate ±0.1 ml / min, column temperature ±5 °C, mobile phase buffer pH ±0.1, and replacement of different chromatographic columns. Six chromatographic conditions were determined and compared with normal conditions.

[0096]

[0097]

Claims

1. A method for testing related substances in Olmesartan Medoxomil Hydrochlorothiazide Tablets, characterized in that: The related substances are: Benzothiadiazine related substance A: Chlorothiazide: Olmesartan: Hydrochlorothiazide dimer: Olefin impurities: Olmesartan dimer: Olmesartan Impurity 21: The inspection method comprises the following steps: (1) Prepare solutions, including blank solution, sensitivity solution, reference solution and test solution; (2) Determination method: Olmesartan medoxomil hydrochlorothiazide tablets related substances were determined by high performance liquid chromatography. After the system was stable, blank solution, sensitivity solution, reference solution and test solution were added respectively, and the chromatogram was recorded. The chromatographic conditions were as follows: Chromatographic column: octylsilane bonded silica gel as filler, detection wavelength: 250nm; flow rate: 1.0±0.1ml / min; column temperature: 25±2℃; injection volume: 5μl, injector temperature: 5℃, mobile phase: phosphoric acid solution: acetonitrile system as mobile phase, mobile phase A is phosphoric acid solution, mobile phase B is acetonitrile, gradient elution is adopted, and the gradient elution is: 。 2. The inspection method according to claim 1, characterized in that: The blank solution is 70% acetonitrile; the mobile phase is: mobile phase A: transfer 1.0 ml of phosphoric acid into 1000 ml of ultrapure water, mix well, and degas by ultrasonication; mobile phase B: acetonitrile; the reference solution: take an appropriate amount of Olmesartan Medoxomil reference substance and hydrochlorothiazide reference substance and place them in a volumetric bottle, add the blank solution to dilute to the scale, and shake well; the sensitivity solution: take an appropriate amount of the reference solution, place it in a volumetric bottle, add the blank solution to dilute to the scale, and shake well; The test solution: take an appropriate amount of the test sample, accurately weigh it, put it in a volumetric bottle, and add diluent to dilute to the scale; The chromatographic column is Waters, C84.6mm×100mm, 3.5μm.

Images