Amlodipine besylate composition, and preparation method and organic impurity detection method thereof

Abstract

The present application provides amlodipine besylate composition and its preparation method and organic impurity detection method, the impurity 1 in the amlododipine besylate composition is not more than 0.2%, the impurity 2 is not more than 0.5%, and the impurity 3 is not more than 0.5%.The preparation method comprises the following steps: raw materials are sequentially added into a reactor in the order of ethanol, butyl hydroxy anisole, amlodipine besylate, glycerol, maltitol and essence for mixing.The detection method adopts high performance liquid chromatography, and the chromatographic conditions comprise that the chromatographic column is octadecyl bonded silica gel chromatographic column, the mobile phase A is a mixed phase of phosphate buffer, methanol and acetonitrile, and the mobile phase B is a mixed phase of methanol and acetonitrile;gradient elution is carried out by using the gradient elution procedure in Table 1.The amlodipine besylate composition of the present application has good amlodipine besylate stability and low impurity content, the detection method of the present application is simple in operation, high in specificity, high in sensitivity, good in durability and repeatability.

Description

Technical Field

[0001] This invention belongs to the field of pharmaceutical and analytical technology, specifically relating to an amlodipine besylate composition, its preparation method, and a method for detecting organic impurities. Background Technology

[0002] Amlodipine is a dihydropyridine calcium channel blocker used to treat hypertension, coronary heart disease, and angina. It can be used alone or in combination with other medications to treat hypertension. It is particularly effective for angina, especially spontaneous angina, and can also be used alone or in combination with other drugs. Currently, the main formulations containing amlodipine are amlodipine besylate tablets and amlodipine besylate oral solution.

[0003] The current Chinese Pharmacopoeia (ChP), United States Pharmacopoeia (USP), British Pharmacopoeia (BP), European Pharmacopoeia (EP), and Japanese Pharmacopoeia (JP) all include quality standards for amlodipine raw materials. Only the current edition of the British Pharmacopoeia includes quality standards for amlodipine besylate oral solution; the other pharmacopoeias do not. However, the related substances methods in the quality standards for amlodipine besylate raw materials included in these pharmacopoeias only control impurities A, B, D, E, F, G, and H. The related substances methods in the quality standards for amlodipine besylate oral solution included in the British Pharmacopoeia only control known impurities D, E, and F. However, when the inventors conducted stability analysis on the original product NORLIQVA, which was first launched in the United States by CMP Development LLC on February 24, 2022, they found that the impurity spectrum contained significantly more impurities than those listed in the British Pharmacopoeia quality standards. Among them, there were three impurities that exceeded the identification limits (named Impurity 1, Impurity 2, and Impurity 3, respectively). These three impurities were not studied or mentioned in the current version of the British Pharmacopoeia's quality standards for oral solutions. Furthermore, when the amlodipine besylate oral solution was analyzed using the quality standards for amlodipine besylate oral solution listed in the British Pharmacopoeia, the obtained spectrum showed that Impurity 2 overlapped with the main peak. Impurity 2 is one of the main degradation impurities of amlodipine besylate. In summary, existing drugs with amlodipine as the main drug, especially amlodipine besylate oral solution, still have the following problems: (1) the production process is not perfect and the product stability is poor, with high content of impurities (especially degradation impurities of amlodipine besylate), and (2) the current quality standard cannot accurately and comprehensively detect the impurities in amlodipine besylate oral solution, which poses a hidden danger to the safety of clinical use.

[0004] The inventors consulted some relevant literature and found that: (1) Regarding the production process, the production process described in the existing literature has unreasonable feeding sequence, which can easily lead to high impurity content and a small number of impurities monitored during product quality control. (2) Regarding the detection of organic impurities, the detection methods described in the existing literature are still unable to comprehensively assess the organic impurities in drugs with amlodipine as the main drug. For example: 1) The method described by Jiang Yunxiao, Song Bin, et al. in "Simultaneous Determination of 13 Impurities in Amlodipine Besylate Tablets by High Performance Liquid Chromatography" has the following problems: the separation degree between the main peak and the impurities does not meet the requirements, the impurity detection ability is insufficient, and it interferes with the detection of impurities. 2) Petr Gibala, Michal Douˇsa. Identification and structure elucidation of a new degradation impurity in the multi-component tablets of amlodipine besylate; the literature mentions that impurity 2 is a high-temperature degradation impurity, but the analytical method in the literature only studies this one impurity and cannot accurately and comprehensively control all organic impurities in the drug. 3) The method described by Liang Jun, Sun Jinxia, ​​et al. in "Simultaneous Determination of the Content of 7 Impurities in Amlodipine Besylate Tablets by HPLC" has problems such as a limited number of impurity types studied, poor analytical method specificity, and inability to accurately and comprehensively control all organic impurities in the drug.

[0005] In summary, there is an urgent need to provide an amlodipine besylate composition with good stability and low impurity content, as well as a method for its preparation, and a detection method that can comprehensively and effectively detect organic impurities in the amlodipine besylate composition, so as to ensure the safety of clinical use of the amlodipine besylate composition. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide an amlodipine besylate composition, its preparation method, and an organic impurity detection method. The amlodipine besylate composition of the present invention exhibits good stability and low impurity content. The detection method of the present invention is simple to operate, highly specific, highly sensitive, and has good durability and repeatability.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] In a first aspect, the present invention provides an amlodipine besylate composition, wherein impurity 1 in the amlodipine besylate composition does not exceed 0.2%, impurity 2 does not exceed 0.5%, and impurity 3 does not exceed 0.5%; wherein the molecular structures of impurity 1, impurity 2, and impurity 3 are as shown in Formula I, Formula II, and Formula III, respectively.

[0009]

[0010] In some embodiments of the present invention, the finished amlodipine besylate composition meets the following impurity limits after being stored for more than 7 days, preferably more than 30 days, more preferably more than 180 days, and most preferably within its shelf life:

[0011] Impurity 1 shall not exceed 0.2%, impurity 2 shall not exceed 0.5%, and impurity 3 shall not exceed 0.5%.

[0012] In some embodiments of the present invention, the finished amlodipine besylate composition meets the following impurity limits after being stored for more than 7 days, preferably more than 30 days, more preferably more than 180 days, and most preferably within its shelf life:

[0013] Impurity D shall not exceed 1.0%, impurity 1 shall not exceed 0.2%, impurity 2 shall not exceed 0.5%, and impurity 3 shall not exceed 0.5%.

[0014] In some embodiments of the present invention, the finished amlodipine besylate composition meets the following impurity limits after being stored for more than 7 days, preferably more than 30 days, more preferably more than 180 days, and most preferably within its shelf life:

[0015] Impurity D shall not exceed 0.7%, impurity 1 shall not exceed 0.2%, impurity 2 shall not exceed 0.5%, and impurity 3 shall not exceed 0.5%.

[0016] In some embodiments of the present invention, the finished amlodipine besylate composition meets the following impurity limits after being stored for more than 7 days, preferably more than 30 days, more preferably more than 180 days, and most preferably within its shelf life:

[0017] Impurity D shall not exceed 0.6%, impurity 1 shall not exceed 0.2%, impurity 2 shall not exceed 0.5%, and impurity 3 shall not exceed 0.5%.

[0018] In some embodiments of the present invention, the finished amlodipine besylate composition contains impurity A not exceeding 0.2%, impurity B not exceeding 0.2%, impurity E not exceeding 0.5%, impurity F not exceeding 0.5%, and impurity G + impurity H not exceeding 0.2%, and the finished product is stored for more than 7 days, preferably more than 30 days, more preferably more than 180 days, and most preferably within its shelf life, meeting the following impurity limits:

[0019] Impurity F shall not exceed 0.5%, impurity D shall not exceed 1.0%, impurity 1 shall not exceed 0.2%, impurity 2 shall not exceed 0.5%, and impurity 3 shall not exceed 0.5%.

[0020] In some embodiments of the present invention, the finished amlodipine besylate composition contains impurity A not exceeding 0.2%, impurity B not exceeding 0.2%, impurity E not exceeding 0.5%, impurity F not exceeding 0.5%, and impurity G + impurity H not exceeding 0.2%, and the finished product is stored for more than 7 days, preferably more than 30 days, more preferably more than 180 days, and most preferably within its shelf life, meeting the following impurity limits:

[0021] Impurity F shall not exceed 0.5%, impurity D shall not exceed 0.7%, impurity 1 shall not exceed 0.2%, impurity 2 shall not exceed 0.5%, and impurity 3 shall not exceed 0.5%.

[0022] In some embodiments of the present invention, the finished amlodipine besylate composition contains impurity A not exceeding 0.2%, impurity B not exceeding 0.2%, impurity E not exceeding 0.5%, impurity F not exceeding 0.5%, and impurity G + impurity H not exceeding 0.2%, and the finished product is stored for more than 7 days, preferably more than 30 days, more preferably more than 180 days, and most preferably within its shelf life, meeting the following impurity limits:

[0023] Impurity F shall not exceed 0.5%, impurity D shall not exceed 0.6%, impurity 1 shall not exceed 0.2%, impurity 2 shall not exceed 0.5%, and impurity 3 shall not exceed 0.5%.

[0024] In some embodiments of the present invention, impurities A, B, E, G, and H are process impurities, impurities D, 1, 2, and 3 are degradation impurities, and impurity F is both a process impurity and a degradation impurity. Information on impurities A, B, D, E, F, G, H, 1, 2, and 3 is shown in Table 2.

[0025] Table 2 Summary of Organic Impurities

[0026]

[0027]

[0028]

[0029] In some embodiments of the present invention, impurities D, 1, 2, and 3 are all degradation products of amlodipine besylate. As the storage time of the amlodipine besylate composition is prolonged, impurities D, 1, 2, and 3 may appear or even accumulate in the amlodipine besylate composition. The statement that "the amlodipine besylate composition meets the following impurity limits after being stored for more than 180 days: impurity D not exceeding 1.0%, impurity 1 not exceeding 0.2%, impurity 2 not exceeding 0.5%, and impurity 3 not exceeding 0.5%" means that the amlodipine besylate composition is within its shelf life and has been stored for more than 180 days, for example, on the 180th, 190th, 200th, 250th, and 300th days of storage, and that every day and every hour during the storage period, impurity D does not exceed 1.0%, impurity 1 does not exceed 0.2%, impurity 2 does not exceed 0.5%, and impurity 3 does not exceed 0.5%." The phrase "stored for more than 180 days" means the 180th day or more, but not exceeding any day within the expiration date (e.g., the 190th, 200th, 250th, or 300th day). When "more than 180 days" refers to the 200th day, the phrase "the finished amlodipine besylate composition meets the following impurity limits after being stored for more than 180 days: impurity D not exceeding 1.0%, impurity 1 not exceeding 0.2%, impurity 2 not exceeding 0.5%, and impurity 3 not exceeding 0.5%" means that when the finished amlodipine besylate composition is 200 days away from the production date, every moment of every day within those 200 days meets the following limits: impurity D not exceeding 1.0%, impurity 1 not exceeding 0.2%, impurity 2 not exceeding 0.5%, and impurity 3 not exceeding 0.5%. In the first aspect, "more than 7 days" and "more than 30 days" have similar meanings to "more than 180 days," differing only in time. For example, when the validity period is 730 days, "more than 7 days" means any day from the 7th, 8th, 9th, ..., 730th day, and "more than 30 days" means any day from the 30th, 31st, 32nd, ..., 730th day.

[0030] In some embodiments of the present invention, the storage conditions described above include a temperature between 0 and 100°C, preferably between 0 and 60°C, more preferably between 0 and 40°C, and even more preferably between 10 and 30°C.

[0031] In some embodiments of the present invention, the amlodipine besylate composition refers to a formulation containing amlodipine besylate, the active ingredient of which may be amlodipine besylate alone, or a combination of amlodipine besylate and other active ingredients; in addition, the dosage form of the formulation includes, but is not limited to, tablets, oral solutions, and capsules.

[0032] In some embodiments of the present invention, a formulation of an amlodipine besylate oral solution (an amlodipine besylate composition in oral solution form) comprises: 1-10 wt% ethanol, 0.01-0.05 wt% butylated hydroxyanisole, 0.09-0.15 wt% amlodipine besylate, 80-85 wt% glycerin, 5-15 wt% maltitol, and 0.005-0.020 wt% flavoring; preferably comprising: 4-6 wt% ethanol, 0.02-0.04 wt% butylated hydroxyanisole, 0.10-0.12 wt% amlodipine besylate, 80-85 wt% glycerin, 10-13 wt% maltitol, and 0.010-0.018 wt% flavoring.

[0033] In some embodiments of the present invention, the formulation of the amlodipine besylate oral solution is: 1-10 wt% ethanol, 0.01-0.05 wt% butylated hydroxyanisole, 0.09-0.15 wt% amlodipine besylate, 80-85 wt% glycerin, 5-15 wt% maltitol, and 0.005-0.020 wt% flavoring; preferably: 4-6 wt% ethanol and 0.02-0.05 wt% butylated hydroxyanisole. 0.04 wt%, amlodipine besylate 0.10–0.12 wt%, glycerin 80–85 wt%, maltitol 10–13 wt%, and flavor 0.010–0.018 wt%; more preferably: ethanol 5.51 wt%, butylated hydroxyanisole 0.032 wt%, amlodipine besylate 0.11 wt%, glycerin 83.20 wt%, maltitol 11.14 wt%, and flavor 0.015 wt%.

[0034] In some embodiments of the present invention, the ethanol is anhydrous ethanol.

[0035] In some embodiments of the present invention, the maltitol is liquid maltitol.

[0036] In some embodiments of the present invention, the flavoring is a pharmaceutically acceptable flavoring, including peppermint flavoring and / or fruit flavoring.

[0037] In some embodiments of the present invention, the fruit flavoring includes one or more of the following: peach flavoring, orange juice flavoring, blackberry flavoring, strawberry flavoring, pineapple flavoring, apple flavoring, lychee flavoring, mango flavoring, and lemon flavoring.

[0038] In a second aspect, the present invention provides a method for preparing the amlodipine besylate composition described in the first aspect, the method comprising the following steps: adding raw materials in the order of ethanol, butylated hydroxyanisole, amlodipine besylate, glycerin, maltitol, and fragrance into a reactor for mixing, wherein the mixing temperature is between 25 and 60°C, preferably between 30 and 50°C, and more preferably between 30 and 40°C.

[0039] In some embodiments of the invention, the mixing is carried out by stirring.

[0040] In some embodiments of the present invention, the formulation of the amlodipine besylate composition comprises: 1-10 wt% ethanol, 0.01-0.05 wt% butylated hydroxyanisole, 0.09-0.15 wt% amlodipine besylate, 80-85 wt% glycerin, 5-15 wt% maltitol, and 0.005-0.020 wt% fragrance; preferably comprising: 4-6 wt% ethanol, 0.02-0.04 wt% butylated hydroxyanisole, 0.10-0.12 wt% amlodipine besylate, 80-85 wt% glycerin, 10-13 wt% maltitol, and 0.010-0.018 wt% fragrance.

[0041] In some embodiments of the present invention, the formulation of the amlodipine besylate composition is: 1-10 wt% ethanol, 0.01-0.05 wt% butylated hydroxyanisole, 0.09-0.15 wt% amlodipine besylate, 80-85 wt% glycerin, 5-15 wt% maltitol, and 0.005-0.020 wt% fragrance; preferably: 4-6 wt% ethanol and 0.02-0.05 wt% butylated hydroxyanisole. 0.04 wt%, amlodipine besylate 0.10–0.12 wt%, glycerin 80–85 wt%, maltitol 10–13 wt%, and flavor 0.010–0.018 wt%; more preferably: ethanol 5.51 wt%, butylated hydroxyanisole 0.032 wt%, amlodipine besylate 0.11 wt%, glycerin 83.20 wt%, maltitol 11.14 wt%, and flavor 0.015 wt%.

[0042] In some embodiments of the present invention, the ethanol is anhydrous ethanol.

[0043] In some embodiments of the present invention, the maltitol is liquid maltitol.

[0044] In some embodiments of the present invention, the flavoring is a pharmaceutically acceptable flavoring, including peppermint flavoring and / or fruit flavoring.

[0045] In some embodiments of the present invention, the fruit flavoring includes one or more of the following: peach flavoring, orange juice flavoring, blackberry flavoring, strawberry flavoring, pineapple flavoring, apple flavoring, lychee flavoring, mango flavoring, and lemon flavoring.

[0046] In some embodiments of the present invention, the preparation method further includes filtering the mixed pharmaceutical solution.

[0047] In some embodiments of the present invention, the filtration is performed using a filter membrane with a pore size of 20 μm; preferably, the filter membrane is made of polypropylene; and / or, the filtration is performed by sequentially passing the drug solution through multiple sets of filter membranes, preferably three sets, and recovering the final filtrate.

[0048] In some embodiments of the present invention, filtration is performed when the temperature of the liquid medicine is ≤30°C.

[0049] In some embodiments of the present invention, the preparation method further includes filling the mixed liquid, preferably the filtered liquid (filtrate), into a container.

[0050] In some embodiments of the present invention, the filling includes filling the liquid medicine into a soda-lime glass molded medicine bottle; preferably, the filling volume is controlled within the range of 160.0±5.0 mL during the filling process.

[0051] Thirdly, the present invention provides an amlodipine besylate composition prepared by the preparation method described in the second aspect; preferably, the amlodipine besylate composition is an oral solution of amlodipine besylate.

[0052] Fourthly, the present invention provides a method for detecting organic impurities in an amlodipine besylate composition. The method employs high-performance liquid chromatography (HPLC), and the chromatographic conditions include: an octadecyl-bonded silica column; mobile phase A being a mixture of phosphate buffer, methanol, and acetonitrile, with a volume ratio of (70–80):(12–18):(12–18); mobile phase B being a mixture of methanol and acetonitrile, with a volume ratio of (30–70):(70–30); elution time of 90 min; and a gradient change of mobile phase A from 95% to 5%, and a gradient change of mobile phase B from 5% to 95%.

[0053] In some embodiments of the present invention, the volume ratio of phosphate buffer, methanol, and acetonitrile in mobile phase A is 75:12.5:12.5.

[0054] In some embodiments of the present invention, the volume ratio of methanol to acetonitrile in mobile phase B is (40-60):(60-40), preferably (45-55):(55-45), and more preferably 50:50.

[0055] In some embodiments of the present invention, gradient elution is performed using the gradient elution procedure in Table 1.

[0056] Table 1 Gradient elution program

[0057]

[0058] In some embodiments of the present invention, the pH value of the phosphate buffer solution is 5.0 to 5.5; preferably 5.3.

[0059] In some embodiments of the present invention, an alkaline reagent is used to adjust the pH of the phosphate buffer solution to 5.0 to 5.5, wherein the alkaline reagent is selected from one or more of sodium hydroxide, potassium hydroxide, and ammonia water; preferably, the alkaline reagent is potassium hydroxide, and / or the concentration of the alkaline reagent is 0.5 to 1.0 mol / L.

[0060] In some embodiments of the present invention, the concentration of phosphate in the phosphate buffer solution is 20-50 mmol / L; preferably, the phosphate is sodium phosphate and / or potassium phosphate.

[0061] In some embodiments of the present invention, the chromatographic conditions further include: a flow rate of 0.75 to 0.85 mL / min; and / or a column temperature of 43 to 47°C, preferably 45°C; and / or a detection wavelength of 238 nm; and / or an injection volume of 10 to 20 μL.

[0062] In some embodiments of the present invention, the chromatographic column has a length of 100 mm, an inner diameter of 4.6 mm, and a particle size of 2.6 μm.

[0063] In some embodiments of the present invention, the chromatographic column is a Kinetex C18 100A, 100mm × 4.6mm, 2.6μm.

[0064] In some embodiments of the present invention, the organic impurities include one or more of impurity A, impurity B, impurity D, impurity E, impurity F, impurity G, impurity H, impurity 1, impurity 2 and impurity 3.

[0065] In some embodiments of the present invention, the amlodipine besylate composition comprises amlodipine besylate tablets and / or amlodipine besylate oral solution. In some specific embodiments, the amlodipine besylate oral solution is the amlodipine besylate oral solution described in the first aspect or the amlodipine besylate oral solution prepared by the preparation method described in the second aspect.

[0066] In some embodiments of the present invention, the detection method further includes the step of preparing a test solution.

[0067] In some embodiments of the present invention, when the amlodipine besylate composition is amlodipine besylate tablets, the step of preparing the test solution includes dissolving the amlodipine besylate tablets in mobile phase A; preferably, the concentration of the amlodipine besylate tablets in the test solution is 0.8 to 1.5 mg / mL.

[0068] In some embodiments of the present invention, when the amlodipine besylate composition is an oral solution of amlodipine besylate, the step of preparing the test solution includes dispersing the oral solution of amlodipine besylate in mobile phase A; preferably, the concentration of the oral solution of amlodipine besylate in the test solution is 0.8 to 1.5 mg / mL.

[0069] In some embodiments of the present invention, the detection method further includes the step of preparing a reference solution; preferably, the step of preparing the reference solution includes dissolving amlodipine besylate reference standard in mobile phase A; more preferably, the concentration of amlodipine besylate in the reference solution is 0.7 μg / mL.

[0070] In some embodiments of the present invention, the detection method further includes the step of preparing a negative sample solution; preferably, the step of preparing a negative sample solution includes dissolving a negative sample in mobile phase A; more preferably, the concentration of the negative sample in the negative sample solution is 0.8 to 1.5 mg / mL.

[0071] Fifthly, the detection method described in the fourth aspect is provided for the application of controlling the content of organic impurities in amlodipine besylate compositions.

[0072] In some embodiments of the present invention, the organic impurities include one or more of impurity A, impurity B, impurity D, impurity E, impurity F, impurity G, impurity H, impurity 1, impurity 2 and impurity 3.

[0073] In some embodiments of the invention, the application includes controlling impurity 1 in the amlodipine besylate composition to not exceed 0.2% and / or impurity 2 to not exceed 0.5% and / or impurity 3 to not exceed 0.5%.

[0074] In some embodiments of the present invention, the application includes controlling the impurity A in the amlodipine besylate composition to be no more than 0.2%, impurity B to be no more than 0.2%, impurity D to be no more than 1.0%, impurity E to be no more than 0.5%, impurity F to be no more than 0.5%, impurity G + impurity H to be no more than 0.2%, impurity 1 to be no more than 0.2%, impurity 2 to be no more than 0.5%, and impurity 3 to be no more than 0.5%.

[0075] In some embodiments of the present invention, the application includes controlling the impurity A in the amlodipine besylate composition to be no more than 0.2%, impurity B to be no more than 0.2%, impurity D to be no more than 0.7%, impurity E to be no more than 0.5%, impurity F to be no more than 0.5%, impurity G + impurity H to be no more than 0.2%, impurity 1 to be no more than 0.2%, impurity 2 to be no more than 0.5%, and impurity 3 to be no more than 0.5%.

[0076] In some embodiments of the present invention, the application includes controlling the impurity A in the amlodipine besylate composition to be no more than 0.2%, impurity B to be no more than 0.2%, impurity D to be no more than 0.6%, impurity E to be no more than 0.5%, impurity F to be no more than 0.5%, impurity G + impurity H to be no more than 0.2%, impurity 1 to be no more than 0.2%, impurity 2 to be no more than 0.5%, and impurity 3 to be no more than 0.5%.

[0077] In some embodiments of the present invention, the application includes controlling the following impurities in amlodipine besylate oral solution to be no more than 0.2% for A, no more than 0.2% for B, no more than 0.6% for D, no more than 0.5% for E, no more than 0.5% for F, no more than 0.2% for G and H, no more than 0.2% for 1, no more than 0.2% for 2, no more than 0.5% for 3.

[0078] The beneficial effects of this invention are as follows:

[0079] The amlodipine besylate composition of the present invention has good stability and low impurity content, and the preparation method is simple. It has good application prospects in the treatment of hypertension, coronary heart disease, and angina pectoris.

[0080] The detection method of this invention is simple to operate, highly specific, highly sensitive, durable, and has good repeatability. When all conditions in the detection method of this invention are preferred, the method can detect multiple organic impurities in the amlodipine besylate composition in a single step, especially when impurities 1, 2, or 3 are present, and the detection results are accurate. The detection method of this invention has good application prospects in controlling the content of organic impurities in amlodipine besylate compositions. Attached Figure Description

[0081] Figure 1 This indicates the results of the specificity test of the detection method of the present invention.

[0082] Figure 2 This indicates the results of the investigation into the types of chromatographic columns.

[0083] Figure 3 This indicates the results of the investigation into the type and proportion of mobile phase B.

[0084] Figure 4 The spectrum shows the characteristic peaks of impurities 1, 2, and 3.

[0085] Figure 5 This indicates the results obtained using the relevant substances detection method for amlodipine besylate oral solution as specified in the British Pharmacopoeia.

[0086] Figure 6The results of gradient elution obtained by using the gradient elution procedure in Table 14 in Comparative Example 2 represent the detection methods and their applications.

[0087] Figure 7 The results of gradient elution obtained by using the gradient elution procedure in Table 15 in Comparative Example 2 represent the detection methods and their applications. Detailed Implementation

[0088] The following examples further illustrate the technology of the present invention. These examples are illustrative and exemplary of the present invention and do not limit the scope of the invention in any way.

[0089] Product Example 1

[0090] An amlodipine besylate oral solution, wherein the formulation of the amlodipine besylate oral solution is as follows: amlodipine besylate 0.11 wt%; anhydrous ethanol 5.51 wt%; butylated hydroxyanisole 0.032 wt%; liquid maltitol 11.14 wt%; peppermint flavor 0.015 wt%; glycerin 83.20 wt%.

[0091] The preparation method of amlodipine besylate oral solution includes the following steps:

[0092] (1) Solution preparation: While stirring, add anhydrous ethanol, butylated hydroxyanisole, amlodipine benzyl sulfonate, glycerin, liquid maltitol and peppermint flavoring to the reactor in sequence and mix evenly. The mixing temperature is 40℃.

[0093] (2) Packaging: After the temperature of the medicine solution obtained in step (1) drops to below 30°C, the medicine solution is filtered through three sets of 20μm pore size polypropylene filter elements and the filtrate is transported to the medicine solution buffer tank. Finally, the filtrate is filled into cleaned and dried sodium-calcium glass molded medicine bottles. During the filling process, the filling volume is controlled within the range of 160.0±5.0mL. After filling, the cap is screwed on and labeled.

[0094] Product Example 2

[0095] The prescription components and preparation method of amlodipine besylate oral solution are the same as those in Example 1, except that the mixing temperature in step (1) of the preparation method is 25°C.

[0096] Product Example 3

[0097] The prescription components and preparation method of amlodipine besylate oral solution are the same as those in Example 1, except that the mixing temperature in step (1) of the preparation method is 50°C.

[0098] Product Example 4

[0099] The prescription components and preparation method of amlodipine besylate oral solution are the same as those in Example 1, except that the mixing temperature in step (1) of the preparation method is 60°C.

[0100] Product Comparison Example 1

[0101] The prescription components and preparation method of amlodipine besylate oral solution are the same as in Example 1, except that step (1) in the preparation method is: while stirring, anhydrous ethanol, butylated hydroxyanisole, glycerin, amlodipine besylate, liquid maltitol and peppermint flavoring are added to the reactor in sequence and mixed evenly at a temperature of 40°C.

[0102] Product Comparison Example 2

[0103] The prescription components and preparation method of amlodipine besylate oral solution are the same as in Example 1, except that step (1) in the preparation method is: while stirring, anhydrous ethanol, butylated hydroxyanisole, glycerin, liquid maltitol, amlodipine besylate and peppermint flavoring are added to the reactor in sequence and mixed evenly at a temperature of 40°C.

[0104] Product Comparison Example 3

[0105] The prescription components and preparation method of amlodipine besylate oral solution are the same as in Example 1, except that step (1) in the preparation method is: while stirring, anhydrous ethanol, butylated hydroxyanisole, liquid maltitol, amlodipine besylate, glycerin and peppermint flavoring are added to the reactor in sequence and mixed evenly at a temperature of 40°C.

[0106] Product Comparison Example 4

[0107] The prescription components and preparation method of amlodipine besylate oral solution are the same as in Example 1, except that step (1) in the preparation method is: while stirring, glycerin, liquid maltitol, amlodipine besylate, anhydrous ethanol, butylated hydroxyanisole and peppermint flavoring are added to the reactor in sequence and mixed evenly at a mixing temperature of 40°C.

[0108] Detection Example 1

[0109] A method for detecting organic impurities in amlodipine besylate oral solution, wherein the method employs high-performance liquid chromatography (HPLC). Chromatographic conditions: Column: Kinetex C18 100A, 100 mm × 4.6 mm, 2.6 μm; Mobile phase A: 0.03 mol / L potassium dihydrogen phosphate solution (pH adjusted to 5.3 with 0.5 mol / L KOH solution) - methanol - acetonitrile (volume ratio 75:12.5:12.5); Mobile phase B: methanol - acetonitrile (volume ratio 50:50); Flow rate: 0.80 mL / min; Column temperature: 45 °C; Detection wavelength: 238 nm; Injection volume: 10 μL. Gradient elution was performed using the gradient elution program shown in Table 1.

[0110] Table 1 Gradient elution program

[0111]

[0112] Preparation of the test solution: Accurately weigh 3.1496 g of amlodipine besylate oral solution, place it in a 10 mL volumetric flask, dilute to the mark with mobile phase A, shake well, filter through a 0.45 μm filter membrane, and collect the filtrate to obtain the test solution.

[0113] Detection: The prepared test solution is injected into the chromatographic conditions described above for testing to obtain the test results.

[0114] Application Example 1 of the Detection Method

[0115] Following the method described in Example 1, the drug solutions obtained from steps (1) of Examples 1-4 were stored at their respective mixing temperatures for 0, 4, and 6 hours, and samples were taken for testing. The results are shown in Table 3. Table 3 shows that as the mixing temperature increases, the total time required for solution preparation decreases significantly. However, the amlodipine besylate oral solution has a high proportion of organic solvents, and excessively high filtration temperatures will increase the risk of compatibility issues between the drug solution and the filter. Therefore, when using high-temperature mixing for solution preparation, the temperature must be lowered to a suitable level, such as below 30°C, after preparation before filtration. The time required for cooling the drug solution is much greater than the time shortened during preparation. Therefore, it is recommended that the mixing temperature not exceed 40°C, which ensures both a low total impurity content in the product and high efficiency throughout the production process.

[0116] Table 3. Effects of different mixing temperatures on product stability and total preparation time.

[0117]

[0118]

[0119] Application Example 2 of the Detection Method

[0120] Following the method described in Example 1, organic impurity analysis was performed on the amlodipine besylate oral solutions obtained in Product Example 1 and Comparative Examples 1-4. The amlodipine besylate oral solutions obtained in Product Example 1 and Comparative Examples 1-4 were simultaneously stored at 60°C, and samples were taken for organic impurity analysis after 7, 14, and 30 days of storage. The results are shown in Table 4. Table 4 shows that the product produced using the feeding sequence of Product Example 1 has a lower total impurity content after long-term storage, indicating good product stability. However, the product produced using the feeding sequence of Comparative Examples 1-4, after 30 days of storage at 60°C, already showed impurity D content very close to the limit of 1.0% set by the British Pharmacopoeia for impurity D, meaning that impurity D poses a high risk of exceeding the limit during the product's shelf life.

[0121] Table 4. The impact of different feeding sequences on product stability

[0122]

[0123]

[0124] Application Example 3 of the Detection Method

[0125] Six portions of the same batch of amlodipine besylate oral solution (batch number 23091661) prepared according to Product Example 1 were taken and processed as follows: Sample 1 was directly tested according to the method of Detection Example 1; Samples 2, 3, and 4 were stored at 60℃ for 7, 14, and 30 days, respectively, and then tested according to the method of Detection Example 1; Samples 5 and 6 were stored at 40℃±2℃ and RH 75%±5% for 90 and 180 days, respectively, and then tested according to the method of Detection Example 1. The test results are shown in Table 5. The results in Table 5 show that degradation impurity D, impurity 1, impurity 2, and impurity 3 were all detected to varying degrees after being stored at high temperature for a certain period of time. However, the content of each of the detected impurities was within the limits required by this invention, indicating that the amlodipine besylate oral solution prepared by the method of this invention has good stability, and the detection method of this invention can detect multiple organic impurities at once, especially when the amlodipine besylate oral solution contains impurities 1, 2, and 3, these three impurities can also be detected.

[0126] Table 5. Stability test results of amlodipine besylate oral solution stored under high temperature conditions.

[0127]

[0128] Application Example 4 of the Detection Method

[0129] Five samples of the original amlodipine besylate oral solution formulation (produced by CMP Development LLC) were tested directly according to the method in Example 1. Samples 2 and 3 were stored at 60°C for 14 and 30 days, respectively, and then tested according to the method in Example 1. Samples 4 and 5 were stored at 40°C ± 2°C and RH 75% ± 5% for 90 and 180 days, respectively, and then tested according to the method in Example 1. The test results are shown in Table 6. The results in Table 6 show that degradation impurities D, impurity 1, impurity 2, and impurity 3 in the original amlodipine besylate oral solution formulation were detected to varying degrees after being stored at high temperature for a certain period of time. The detection amount of impurity D reached 0.87% after 30 days of storage at 60°C, which is very close to the limit of 1.0% set by the British Pharmacopoeia for impurity D. That is, impurity D poses a high risk of exceeding the limit during the product's shelf life. Furthermore, a comparison of the impurity detection amounts in Tables 5 and 6 shows that the impurity detection amount of the amlodipine besylate oral solution prepared using the preparation method of the present invention is significantly lower than that of the original amlodipine besylate oral solution formulation, indicating that the amlodipine besylate oral solution of the present invention has better stability and lower impurity content.

[0130] Table 6. Stability test results of the original formulation of amlodipine besylate oral solution stored under high temperature conditions.

[0131]

[0132] Methodological validation (all amlodipine besylate oral solutions used were obtained from product Example 1).

[0133] (I) Specificity Investigation Experiment

[0134] 1. Chromatographic conditions for high performance liquid chromatography (HPLC): The column was a Kinetex C18 100A, 100 mm × 4.6 mm, 2.6 μm; mobile phase A was 0.03 mol / L potassium dihydrogen phosphate solution (adjusted to pH 5.3 with 0.5 mol / L KOH solution) - methanol - acetonitrile (volume ratio 75:12.5:12.5); mobile phase B was methanol - acetonitrile (volume ratio 50:50); flow rate was 0.80 mL / min; column temperature was 45 ℃; detection wavelength was 238 nm; injection volume was 10 μL. Gradient elution was performed using the gradient elution program shown in Table 1.

[0135] 2. Prepare each solution according to the following steps, and inject each solution into a 10 μL sample for analysis. Simultaneously, inject 10 μL of mobile phase A as a solvent blank control. The results are as follows: Figure 1As shown; the detection results indicate that mobile phase A and the negative sample do not interfere with the detection of known organic impurities, the separation of each impurity is good, and the detection method has good specificity. The preparation steps of each solution are as follows:

[0136] (1) Preparation of test solution: Accurately weigh 3.1496 g of amlodipine besylate oral solution, place it in a 10 mL volumetric flask, dilute to the mark with mobile phase A, shake well, filter through a 0.45 μm filter membrane, and take the filtrate to obtain the test solution.

[0137] (2) Preparation of negative sample solution: Accurately weigh 3.1409 g of negative sample (i.e., an oral solution containing only the prescription ingredients other than amlodipine besylate, prepared according to the prescription and preparation method of amlodipine besylate oral solution described in Product Example 1), place it in a 10 mL volumetric flask, dilute to the mark with mobile phase A, shake well, filter through a 0.45 μm filter membrane, and take the filtrate to obtain the negative sample solution.

[0138] (3) Preparation of spiked test solution: Accurately weigh appropriate amounts of reference standards A, B, D, E, F, G, H, 1, 2 and 3, add them to mobile phase A to dissolve and dilute them to prepare reference standard stock solutions containing approximately 0.4 mg / mL of each reference standard (each organic impurity corresponds to one organic impurity reference standard stock solution, and 10 organic impurities yield 10 organic impurity reference standard stock solutions). Accurately measure 0.2 mL each of impurity A, impurity B, impurity G, and impurity 1 reference stock solutions and place them in a 10 mL volumetric flask. Add 1 mL each of impurity 2, impurity 3, and impurity D reference stock solutions, and 0.5 mL each of impurity E and impurity F reference stock solutions. Dilute to the mark with mobile phase A and shake well to obtain a mixed organic impurity dilution. Accurately weigh 3.1359 g of amlodipine besylate oral solution and place it in a 10 mL volumetric flask. Accurately add 1 mL of the mixed organic impurity dilution and dilute to the mark with mobile phase A. Shake well and filter through a 0.45 μm filter membrane. Collect the filtrate to obtain the spiked test solution.

[0139] (II) Durability Testing

[0140] 1. Chromatographic conditions for high-performance liquid chromatography (HPLC): The column was a Kinetex C18 100A, 100 mm × 4.6 mm, 2.6 μm; mobile phase A was 0.03 mol / L potassium dihydrogen phosphate solution-methanol-acetonitrile (v / v ratio 75:12.5:12.5); mobile phase B was methanol-acetonitrile (v / v ratio 50:50); the detection wavelength was 238 nm; the injection volume was 10 μL. The robustness of different flow rates (0.75 mL / min, 0.80 mL / min, 0.85 mL / min), different column temperatures (43℃, 45℃, and 47℃), different pH values ​​of potassium dihydrogen phosphate solution (5.2, 5.3, 5.4, and 3.5), and different Kinetex C18 columns (size: 100A, 100 mm × 4.6 mm, 2.6 μm) was investigated. Gradient elution was performed using the gradient elution program shown in Table 1.

[0141] 2. Preparation of System Suitability Solutions: Accurately weigh appropriate amounts of reference standards A, B, D, E, F, G, H, 1, 2, and 3, respectively. Add mobile phase A to dissolve and dilute the organic impurity reference standards to prepare reference standard stock solutions containing approximately 0.4 mg / mL of each organic impurity reference standard (one organic impurity reference standard stock solution corresponds to one organic impurity reference standard stock solution; 10 organic impurities yield 10 organic impurity reference standard stock solutions). Accurately measure 0.2 mL each of the reference standard stock solutions for impurities A, B, G, and 1, and place them in a 10 mL volumetric flask. Add 1 mL each of the reference standard stock solutions for impurities 2, 3, and D, and 0.5 mL each of the reference standard stock solutions for impurities E and F. Dilute to the mark with mobile phase A and mix well to obtain a mixed organic impurity diluted solution. Accurately weigh 36.07 mg of amlodipine besylate raw material, place it in a 10 mL volumetric flask, add mobile phase A to dissolve and dilute to the mark, and mix well to obtain an amlodipine besylate raw material stock solution. Accurately measure 1 mL of the mixed organic impurity dilution solution and place it in a 10 mL volumetric flask. Accurately add 1 mL of amlodipine besylate raw material stock solution, dilute to the mark with mobile phase A, and shake well to obtain the system suitability solution.

[0142] 3. The system suitability solution prepared in step 2 was injected at a volume of 10 μL and detected under the chromatographic conditions of step 1. The detection results are shown in Tables 7 to 10. The results show that the chromatographic conditions of the present invention are robust. The pH value test results also show that when the pH value is 5.2 to 5.4, the separation effect of each impurity peak is better, while when the pH value is 3.5, impurity 2 overlaps with the main peak.

[0143] Table 7 Results of the investigation at different column temperatures (peak resolution in system suitability solution)

[0144] Column temperature (°C) Impurity D impurity F Amlodipine Impurity 2 Impurity E Impurity G Impurity B Impurity 3 Impurity 1 Impurity A 43 N / A 7.40 13.66 5.24 10.78 11.58 22.15 4.72 17.23 24.41 45 N / A 7.10 13.58 5.76 10.92 11.20 23.68 4.34 17.18 24.05 47 N / A 6.71 13.42 6.43 10.96 10.97 26.16 3.90 17.21 23.62

[0145] Table 8. Results of the investigation of potassium dihydrogen phosphate solution at different pH values ​​(peak separation in system suitability solution)

[0146]

[0147] Table 9. Results of the investigation at different flow rates (peak separation in the system suitability solution)

[0148] Flow rate (mL / min) Impurity D impurity F Amlodipine Impurity 2 Impurity E Impurity G Impurity B Impurity 3 Impurity 1 Impurity A 0.75 N / A 7.06 13.41 5.77 10.84 11.51 21.08 4.64 16.84 23.52 0.80 N / A 7.10 13.58 5.76 10.92 11.20 23.68 4.34 17.18 24.05 0.85 N / A 7.12 13.5 5.65 10.94 10.95 26.79 4.06 17.53 24.51

[0149] Table 10 Results of the evaluation of different Kinetex C18 columns (system suitability, peak resolution in solution)

[0150] chromatographic column Impurity D impurity F Amlodipine Impurity 2 Impurity E Impurity G Impurity B Impurity 3 Impurity 1 Impurity A Column 1 N / A 7.10 13.58 5.76 10.92 11.20 23.68 4.34 17.18 24.05 Column 2 N / A 5.83 10.28 4.18 9.93 8.24 27.19 2.75 15.70 20.55

[0151] (III) Sensitivity Testing

[0152] 1. Chromatographic conditions for high performance liquid chromatography (HPLC): The column was a Kinetex C18 100A, 100 mm × 4.6 mm, 2.6 μm; mobile phase A was 0.03 mol / L potassium dihydrogen phosphate solution (adjusted to pH 5.3 with 0.5 mol / L KOH solution) - methanol - acetonitrile (volume ratio 75:12.5:12.5); mobile phase B was methanol - acetonitrile (volume ratio 50:50); flow rate was 0.80 mL / min; column temperature was 45 ℃; detection wavelength was 238 nm; injection volume was 10 μL. Gradient elution was performed using the gradient elution program shown in Table 1.

[0153] 2. Accurately weigh appropriate amounts of reference standards A, B, D, E, F, G, H, 1, 2, and 3, respectively. Add each to mobile phase A to dissolve and dilute the organic impurity reference standards to prepare stock solutions containing approximately 0.4 mg / mL of each organic impurity reference standard (one stock solution for each organic impurity, yielding 10 stock solutions for 10 organic impurities). Simultaneously, accurately weigh 7.021 mg of amlodipine besylate reference standard, place it in a 20 mL volumetric flask, add mobile phase A to dissolve the reference standard, and dilute to the mark. Shake well to obtain the amlodipine besylate stock solution. Take appropriate amounts of the amlodipine besylate stock solution and each organic impurity stock solution, and dilute with mobile phase A until the signal-to-noise ratio (S / N) of amlodipine and each organic impurity is greater than 10. This is the limit of quantitation, and the limit of detection is greater than 3. The detection results are shown in Table 11. As shown in Table 11, all organic impurities and amlodipine can be accurately quantified at concentrations above 0.05% of the test solution concentration, and can be effectively detected at concentrations above 0.025% of the test solution concentration. This indicates that the detection method of the present invention has good sensitivity.

[0154] Table 11 Summary of sensitivity test results for each component

[0155]

[0156] (iv) Investigation of Chromatographic Column Types

[0157] 1. Chromatographic conditions for high performance liquid chromatography (HPLC): Mobile phase A was 0.03 mol / L potassium dihydrogen phosphate solution (adjusted to pH 5.3 with 0.5 mol / L KOH solution) - methanol - acetonitrile (volume ratio 75:12.5:12.5); mobile phase B was methanol - acetonitrile (volume ratio 50:50); detection wavelength was 238 nm; injection volume was 10 μL; the detection results of different types of columns (column ① Kinetex C18 100A, 100 mm × 4.6 mm, 2.6 μm; column ② Waters SPHERISORB ODS1 C18, 250 mm × 4.0 mm, 5 μm; column ③ GL Inertsil ODS-3C18, 250 mm × 4.6 mm, 5 μm) were investigated. Gradient elution was performed using the gradient elution program shown in Table 1.

[0158] 2. Preparation of System Suitability Solutions: Accurately weigh appropriate amounts of reference standards A, B, D, E, F, G, H, 1, 2, and 3, respectively. Add each to mobile phase A to dissolve and dilute the organic impurity reference standards to prepare stock solutions containing approximately 0.4 mg / mL of each organic impurity reference standard (one stock solution corresponds to each organic impurity; 10 stock solutions are obtained for 10 organic impurities). Accurately measure 0.2 mL each of the stock solutions of impurity A, impurity B, impurity G, and impurity 1, place them in a 10 mL volumetric flask, add 1 mL each of the stock solutions of impurities 2, 3, and D, and 0.5 mL each of the stock solutions of impurities E and F, dilute to the mark with mobile phase A, and shake well to obtain a mixed organic impurity diluted solution. Accurately weigh 36.07 mg of amlodipine besylate raw material and place it in a 10 mL volumetric flask. Add mobile phase A to dissolve and dilute to the mark, then shake well to obtain amlodipine besylate raw material stock solution. Accurately measure 1 mL of the mixed organic impurity dilution solution and place it in a 10 mL volumetric flask. Accurately add 1 mL of amlodipine besylate raw material stock solution, dilute to the mark with mobile phase A, and shake well to obtain a system suitability solution.

[0159] 3. Inject the system suitability solution prepared in step 2 at a volume of 10 μL and detect it using columns ①, ②, and ③ respectively, according to the chromatographic conditions described in step 1. The detection results are as follows: Figure 2 As shown; the detection results indicate that: when the chromatographic column is column ②, the known impurities are not separated; when the chromatographic column is column ③, the separation degree of impurities B and impurities 3 is poor; and when the chromatographic column is column ①, all organic impurities can be completely separated.

[0160] (V) Investigation on the type and proportion of mobile phase B

[0161] 1. Chromatographic conditions for high performance liquid chromatography (HPLC): The column was a Kinetex C18 100A, 100 mm × 4.6 mm, 2.6 μm; mobile phase A was 0.03 mol / L potassium dihydrogen phosphate solution (adjusted to pH 5.3 with 0.5 mol / L KOH solution) - methanol - acetonitrile (volume ratio 75:12.5:12.5); mobile phase B was methanol - acetonitrile (volume ratios of 100:0, 60:40, 50:50, 45:55, 30:70); the detection wavelength was 238 nm; the injection volume was 10 μL. Gradient elution was performed using the gradient elution program shown in Table 1.

[0162] 2. Preparation of System Suitability Solutions: Accurately weigh appropriate amounts of reference standards A, B, D, E, F, G, H, 1, 2, and 3, respectively. Add mobile phase A to dissolve and dilute the organic impurity reference standards to prepare reference standard stock solutions containing approximately 0.4 mg / mL of each organic impurity reference standard (one organic impurity reference standard stock solution corresponds to one organic impurity reference standard stock solution; 10 organic impurities yield 10 organic impurity reference standard stock solutions). Accurately measure 0.2 mL each of the reference standard stock solutions of impurity A, impurity B, impurity G, and impurity 1, and place them in a 10 mL volumetric flask. Add 1 mL each of the reference standard stock solutions of impurities 2, 3, and D, and 0.5 mL each of the reference standard stock solutions of impurities E and F. Dilute to the mark with mobile phase A, and shake well to obtain a mixed organic impurity diluted solution. Accurately weigh 36.07 mg of amlodipine besylate raw material, place it in a 10 mL volumetric flask, add mobile phase A to dissolve and dilute to the mark, and shake well to obtain an amlodipine besylate raw material stock solution. Accurately measure 1 mL of the mixed organic impurity dilution solution and place it in a 10 mL volumetric flask. Accurately add 1 mL of amlodipine besylate raw material stock solution, dilute to the mark with mobile phase A, and shake well to obtain the system suitability solution.

[0163] 3. Inject the system suitability solution prepared in step 2 at a volume of 10 μL and detect it using different mobile phases B under the chromatographic conditions described in step 1. The detection results are as follows: Figure 3 As shown in the figure. The detection results indicate that when mobile phase B is 100% methanol, only 3 organic impurities can be detected, while the remaining organic impurities cannot be effectively detected; when the volume ratio of methanol to acetonitrile is 30:70, only 8 out of 10 organic impurities can be detected; when the volume ratio of methanol to acetonitrile is 45:55 and 60:40, the separation of impurity G and impurity H is poor, and the separation of impurity B and impurity 3 is also poor; when the volume ratio of methanol to acetonitrile is 50:50, all organic impurities can be well separated and the separation effect from the main peak is good.

[0164] (vi) Qualitative analysis of impurities 1, 2, and 3.

[0165] 1. High-performance liquid chromatography (HPLC) conditions: The chromatographic column was Aglient Bonus-RP, 150 mm × 4.6 mm, 3.5 μm; mobile phase A was 2.3 g / L ammonium acetate-methanol-acetonitrile (v / v 60:10:30); mobile phase B was methanol-acetonitrile (v / v 50:50); the flow rate was 1.0 mL / min; the column temperature was 45 ℃; the detection wavelength was 237 nm; and the injection volume was 50 μL. Gradient elution was performed using the gradient elution program shown in Table 12.

[0166] Table 12 Gradient elution program

[0167]

[0168] High performance liquid chromatography-mass spectrometry conditions: Ion source: ESI, positive ion mode; Nebulizer gas flow rate: 2.0 L / min; Drying gas flow rate: 5.0 L / min; Heating gas flow rate: 7.0 L / min; Desolvation temperature: 450℃; Desolvation line temperature: 200℃; Q1 mode scanning program is shown in Table 13.

[0169] Table 13 Q1 Pattern Scanning Procedure

[0170]

[0171] 2. Preparation of test solution: Accurately weigh 3.1496 g of sample 4 (i.e., amlodipine besylate oral solution sample stored at 60℃ for 30 days) from the application example 3 of the detection method, place it in a 10 mL volumetric flask, dilute to the mark with 50% v / v acetonitrile, shake well, filter through a 0.45 μm filter membrane, and collect the filtrate to obtain the test solution.

[0172] 3. Take 50 μL of the test solution prepared in step 2 and analyze it using high performance liquid chromatography-mass spectrometry. The results are as follows: Figure 4 As shown. From Figure 4 As can be seen, the mass spectra of the three degradation impurities show that the m / z of impurity 1 is 392, the m / z of impurity 2 is 421, and the m / z of impurity 3 is 392, which are consistent with the molecular weights of the three impurities (compounds with CAS numbers 496024-43-2, 2387405-44-7, and 194472-27-0).

[0173] In addition, the inventors conducted stability and repeatability tests on the solutions (including the test solution and the amlodipine besylate reference solution). The results of the solution stability test showed that the test solution (RSD of amlodipine besylate = 1.0%, and no impurities were detected) and the amlodipine besylate reference solution (RSD = 2.2%) had good stability. The results of the repeatability test showed that the detection method of the present invention had good repeatability (six test solutions were prepared in parallel and tested, and no impurities were detected in each sample).

[0174] Detection methods and their applications Comparative Example 1

[0175] The organic impurities in amlodipine besylate oral solution were detected using the method (high performance liquid chromatography) described in the British Pharmacopoeia quality standards.

[0176] 1. High-performance liquid chromatography (HPLC) conditions: The chromatographic column was a Kinetex C18 100A, 100 mm × 4.6 mm, 2.6 μm; mobile phase A was 0.03 mol / L potassium dihydrogen phosphate solution (adjusted to pH 3.0 with phosphoric acid) - methanol (v / v ratio 45:55); mobile phase B was 0.03 mol / L potassium dihydrogen phosphate solution (adjusted to pH 3.0 with phosphoric acid) - methanol (v / v ratio 30:70); the flow rate was 0.60 mL / min; the column temperature was room temperature; the detection wavelength was 238 nm; and the injection volume was 10 μL. Gradient elution was performed using the gradient elution program shown in Table 14.

[0177] Table 14 Gradient elution program

[0178]

[0179] 2. Prepare each solution according to the following steps, and inject each solution at a volume of 10 μL for analysis. Simultaneously, inject 10 μL of mobile phase A (0.03 mol / L potassium dihydrogen phosphate solution (adjusted to pH 3.0 with phosphoric acid) - methanol (volume ratio 45:55). (Note: In this comparative example, mobile phase A is always 0.03 mol / L potassium dihydrogen phosphate solution (adjusted to pH 3.0 with phosphoric acid) - methanol (volume ratio 45:55)) as a solvent blank control. The results are as follows: Figure 5 As shown; the detection results indicate that: the peak position of impurity 2 coincides with the main peak; the excipient peak interferes with the accurate integration of the impurity peak; the separation between impurity H and impurity B peaks is poor. Therefore, the detection method for organic impurities in amlodipine besylate oral solution described in the British Pharmacopoeia quality standards cannot effectively detect and control the novel degradation impurity 2, which has not been studied or mentioned, in amlodipine besylate oral solution. The preparation steps for each solution are as follows:

[0180] (1) Preparation of impurity H reference solution: Accurately weigh 2.444 mg of impurity H reference standard, place it in a 10 mL volumetric flask, dilute to the mark with mobile phase A, and shake well to obtain impurity H reference solution.

[0181] (2) Preparation of impurity 2 reference solution: Accurately weigh 1.002 g of impurity 2 reference standard, place it in a 10 mL volumetric flask, dilute to the mark with mobile phase A, and shake well to obtain impurity 2 reference solution.

[0182] (3) Preparation of organic impurity reference standard mixed solution: Accurately weigh appropriate amounts of impurity A, B, D, E, F, G, H, 1, 2 and 3 reference standards, place them in the same 10 mL volumetric flask, dilute to the mark with mobile phase A, shake well, and you will get an organic impurity reference standard mixed solution containing approximately 0.4 mg / mL of each reference standard.

[0183] (4) Preparation of negative sample solution: Accurately weigh 3.1409 g of the negative sample (i.e., an oral solution containing only the prescription ingredients other than amlodipine besylate) that has been stored at 60℃ for 30 days (i.e., an oral solution prepared according to the prescription and preparation method of amlodipine besylate oral solution described in Product Example 1), place it in a 10 mL volumetric flask, dilute to the mark with mobile phase A, shake well, filter through a 0.45 μm filter membrane, and take the filtrate to obtain the negative sample solution.

[0184] (5) Preparation of spiked test solution: Accurately weigh appropriate amounts of reference standards A, B, D, E, F, G, H, 1, 2 and 3, add each to mobile phase A to dissolve and dilute the reference standards to prepare an organic impurity reference standard stock solution containing approximately 0.4 mg / mL of each reference standard (each organic impurity corresponds to one organic impurity reference standard stock solution, and 10 organic impurities will yield 10 organic impurity reference standard stock solutions). Accurately measure 0.2 mL each of impurity A, impurity B, impurity G, and impurity 1 reference stock solutions and place them in a 10 mL volumetric flask. Add 1 mL each of impurity 2, impurity 3, and impurity D reference stock solutions and 0.5 mL each of impurity E and impurity F reference stock solutions. Dilute to the mark with mobile phase A and shake well to obtain a mixed organic impurity dilution. Accurately weigh 3.1359 g of amlodipine besylate oral solution obtained from product example 1 and place it in a 10 mL volumetric flask. Accurately add 1 mL of the mixed impurity dilution and dilute to the mark with mobile phase A. Shake well and filter through a 0.45 μm filter membrane. Take the filtrate to obtain the spiked test solution.

[0185] Detection methods and their applications Comparative Example 2

[0186] The detection was performed according to the chromatographic conditions described in the literature "Simultaneous Determination of the Content of 7 Impurities in Amlodipine Besylate Tablets by HPLC".

[0187] 1. High-performance liquid chromatography conditions: The chromatographic column is C10. 18 The column was 250 mm × 4.6 mm, 5 μm in diameter; mobile phase A was 0.1% phosphoric acid solution (pH adjusted to 3.5 with ammonia) - acetonitrile - methanol (volume ratio 80:10:10); mobile phase B was acetonitrile - methanol (volume ratio 70:30); flow rate was 1.2 mL / min; column temperature was 30 °C; detection wavelength was 237 nm; injection volume was 20 μL. Gradient elution was performed using the gradient elution program in Table 15.

[0188] Table 15 Gradient elution program

[0189]

[0190] 2. Prepare each solution according to the following steps, and inject each solution into a 20 μL sample for analysis. The results are as follows: Figure 6 As shown; the detection results indicate that impurity 2 is wrapped together with the main peak, impurity G and impurity H are poorly separated, and the negative sample solution interferes with the detection of known impurities.

[0191] (1) Preparation of system suitability solution: Accurately weigh appropriate amounts of impurity reference standards A, B, D, E, F, G, H, 1, 2, and 3, and place them in the same 10 mL volumetric flask. Dilute to the mark with mobile phase A (0.1% phosphoric acid solution (adjusted to pH 3.5 with ammonia) - acetonitrile - methanol (volume ratio 80:10:10)), and shake well to obtain a mixed solution of organic impurity reference standards containing approximately 0.4 mg / mL of each reference standard. Accurately weigh 14.165 mg of amlodipine besylate reference standard and place it in a 10 mL volumetric flask. Accurately add 1 mL of the mixed solution of organic impurity reference standards, and dilute to the mark with mobile phase A (0.1% phosphoric acid solution (adjusted to pH 3.5 with ammonia) - acetonitrile - methanol (volume ratio 80:10:10)), shake well, filter through a 0.45 μm filter membrane, and collect the filtrate to obtain the system suitability solution.

[0192] (2) Preparation of negative sample solution: Accurately weigh 3.2693 g of negative sample (i.e., an oral solution containing only the prescription ingredients other than amlodipine besylate, prepared according to the prescription and preparation method of amlodipine besylate oral solution described in Product Example 1), place it in a 10 mL volumetric flask, dilute to the mark with mobile phase A (0.1% phosphoric acid solution (adjusted to pH 3.5 with ammonia water) - acetonitrile - methanol (volume ratio of 80:10:10)), shake well, filter through a 0.45 μm filter membrane, and take the filtrate to obtain the negative sample solution.

[0193] 3. To verify the detection results obtained in step 2 (e.g.) Figure 6(As shown) Whether this was due to a relatively short gradient elution time, the inventors extended the gradient elution time to 90 min, as shown in Table 16. Then, the two solutions prepared in step 2 were injected separately at a volume of 20 μL for detection (only the gradient elution program in Table 15 was replaced with that in Table 16; other chromatographic conditions remained the same as in step 1). The detection results are as follows: Figure 7 As shown; the detection results indicate that even when the elution time is extended to 90 min, impurity 2 is still wrapped together with the main peak. The separation of impurities G and H is slightly improved, but the separation degree is still poor, and the negative sample solution still interferes with the detection of known impurities.

[0194] The results of this comparative example show that the chromatographic conditions in step 1 of this comparative example have the problem of poor specificity and inability to accurately and comprehensively control 10 kinds of organic impurities.

[0195] Table 16 Gradient Elution Procedure

[0196]

[0197] It should be noted that the embodiments described above are only for explaining the present invention and do not constitute any limitation on the present invention. The present invention has been described with reference to embodiments, but it should be understood that the terms used therein are descriptive and explanatory terms, not limiting terms. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention. Although the present invention described herein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed herein; on the contrary, the present invention can be extended to all other methods and applications having the same function.

Claims

1. A composition of amlodipine benzylsulfonate, characterized in that, The amlodipine besylate composition contains impurity 1 not exceeding 0.2%, impurity 2 not exceeding 0.5%, and impurity 3 not exceeding 0.5%; wherein the molecular structures of impurity 1, impurity 2, and impurity 3 are shown in Formula I, Formula II, and Formula III, respectively.

2. The amlodipine besylate composition according to claim 1, characterized by, The finished amlodipine besylate composition, after being stored for more than 7 days, preferably more than 30 days, more preferably more than 180 days, and most preferably within its shelf life, meets the following impurity limits: Impurity 1 shall not exceed 0.2%, impurity 2 shall not exceed 0.5%, and impurity 3 shall not exceed 0.5%.

3. The amlodipine besylate composition according to claim 2, characterized by, The finished amlodipine besylate composition contains impurities A not exceeding 0.2%, impurity B not exceeding 0.2%, impurity E not exceeding 0.5%, impurity F not exceeding 0.5%, and impurities G and H not exceeding 0.2%. Furthermore, the finished product meets the following impurity limits after being stored for at least 7 days, preferably at least 30 days, more preferably at least 180 days, and most preferably within its shelf life: Impurity F shall not exceed 0.5%, impurity D shall not exceed 1.0%, impurity 1 shall not exceed 0.2%, impurity 2 shall not exceed 0.5%, and impurity 3 shall not exceed 0.5%.

4. The ambrisentan composition of claim 2 or 3, wherein The storage conditions include a temperature between 0 and 100°C, preferably between 0 and 60°C, and more preferably between 0 and 40°C; And / or, the formulation of the amlodipine besylate composition comprises: 1-10 wt% ethanol, 0.01-0.05 wt% butylated hydroxyanisole, 0.09-0.15 wt% amlodipine besylate, 80-85 wt% glycerin, 5-15 wt% maltitol, and 0.005-0.020 wt% fragrance; preferably: 4-6 wt% ethanol, 0.02-0.04 wt% butylated hydroxyanisole, 0.10-0.12 wt% amlodipine besylate, 80-85 wt% glycerin, 10-13 wt% maltitol, and 0.010-0.018 wt% fragrance.

5. The process for preparing the amlodipine besylate composition according to any one of claims 1 to 4, characterized by, The preparation method includes the following steps: adding raw materials in the order of ethanol, butylated hydroxyanisole, amlodipine benzyl sulfonate, glycerin, maltitol, and flavoring into a reactor and mixing them. The mixing temperature is between 25 and 60°C, preferably between 30 and 50°C, and more preferably between 30 and 40°C.

6. The production method according to claim 5, characterized by, The formulation of the amlodipine besylate composition comprises: 1-10 wt% ethanol, 0.01-0.05 wt% butylated hydroxyanisole, 0.09-0.15 wt% amlodipine besylate, 80-85 wt% glycerin, 5-15 wt% maltitol, and 0.005-0.020 wt% fragrance; preferably: 4-6 wt% ethanol, 0.02-0.04 wt% butylated hydroxyanisole, 0.10-0.12 wt% amlodipine besylate, 80-85 wt% glycerin, 10-13 wt% maltitol, and 0.010-0.018 wt% fragrance; And / or, the ethanol is anhydrous ethanol; And / or, the maltitol is liquid maltitol; And / or, the flavoring is a pharmaceutically acceptable flavoring, including peppermint flavoring and / or fruit flavoring; And / or, the preparation method further includes filtering and / or filling the mixed drug solution; preferably, the filtration is performed using a filter membrane with a pore size of 20 μm, and / or the filtration is performed when the drug solution temperature is ≤30°C.

7. An amlodipine besylate composition prepared by the preparation method according to claim 5 or 6; preferably, the amlodipine besylate composition is an oral solution of amlodipine besylate.

8. The method for detecting organic impurities in the amlodipine besylate composition according to any one of claims 1 to 4, 7, characterized by, The detection method employs high-performance liquid chromatography (HPLC), and the chromatographic conditions include: an octadecyl bonded silica column; mobile phase A is a mixture of phosphate buffer, methanol, and acetonitrile, with a volume ratio of (70-80):(12-18):(12-18), preferably 75:12.5:12.5; mobile phase B is a mixture of methanol and acetonitrile, with a volume ratio of (30-70):(70-30), preferably (40-60):(60-40), more preferably (45-55):(55-45), and even more preferably 50:

50. Gradient elution was performed using the gradient elution procedure shown in Table 1: Table 1 Gradient elution program 9. The detection method according to claim 8, characterized in that, The organic impurities include one or more of the following: impurity A, impurity B, impurity D, impurity E, impurity F, impurity G, impurity H, impurity 1, impurity 2, and impurity 3. And / or, the pH value of the phosphate buffer solution is 5.0 to 5.5; preferably, the concentration of phosphate in the phosphate buffer solution is 20 to 50 mmol / L; more preferably, the phosphate is sodium phosphate and / or potassium phosphate. And / or, the chromatographic conditions further include: a flow rate of 0.75–0.85 mL / min; and / or, a column temperature of 43–47 °C, preferably 45 °C; and / or, a detection wavelength of 238 nm; and / or, an injection volume of 10–20 μL; and / or, the column length of the chromatographic column is 100 mm, the inner diameter is 4.6 mm, and the silica gel particle size is 2.6 μm.

10. The detection method according to claim 8 or 9, characterized in that, The detection method further includes the step of preparing a test solution; preferably, the step of preparing the test solution includes dispersing the amlodipine besylate composition in the mobile phase A; preferably, the concentration of the amlodipine besylate composition in the test solution is 0.8-1.5 mg / mL; And / or, the detection method further includes the step of preparing a reference solution; preferably, the step of preparing the reference solution includes dissolving amlodipine besylate reference standard in the mobile phase A; more preferably, the concentration of amlodipine besylate in the reference solution is 0.7 μg / mL; And / or, the detection method further includes the step of preparing a negative sample solution; preferably, the step of preparing a negative sample solution includes dissolving a negative sample in the mobile phase A; more preferably, the concentration of the negative sample in the negative sample solution is 0.8 to 1.5 mg / mL.

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