Synchronous detection method for impurities contained in candesartan cilexetil and amlodipine besylate

Abstract

The invention relates to a synchronous detection method for impurities contained in candesartan cilexetil and amlodipine besylate, which is suitable for quality control of compound preparations. According to the method, a high performance liquid chromatography technology is adopted, an octadecyl silane bonded silica gel column is used as a chromatographic column, gradient elution conditions are optimized, a water-acetonitrile-trifluoroacetic acid mixed solution is used as a mobile phase A, and an acetonitrile-water-trifluoroacetic acid mixed solution is used as a mobile phase B; according to the method, the impurity contents of amlodipine besylate and candesartan cilexetil are respectively detected under the wavelengths of 240 nm and 253 nm through gradient elution, the separation degree R value is greater than 1.5, the detection sensitivity is high, and the lower quantification limit reaches 0.05%. The method can simultaneously separate and quantify various process impurities and degradation impurities of candesartan cilexetil and amlodipine besylate in the compound preparation, and has the characteristics of high efficiency, accuracy and stability. The method is easy and convenient to operate, low in cost and suitable for compound preparation quality control under the industrial production condition, and scientific support can be provided for improving the medicine quality standard.

Description

Technical Field

[0001] The invention relates to the technical field of drug analysis, in particular to a method for synchronously detecting impurities contained in candesartan cilexetil and amlodipine besylate. Background Art

[0002] Compound drug preparations play an increasingly important role in clinical treatment due to their synergistic therapeutic effects, simplified medication regimens, and improved patient compliance. The compound preparation of candesartan cilexetil and amlodipine besylate is one of the classic combinations used to treat hypertension and its complications. It has been widely used because of its significant antihypertensive effect, stable onset, and low side effects. However, the quality control of compound preparations is more complicated than that of single-ingredient drugs, especially the detection technology of impurities contained in candesartan cilexetil and amlodipine besylate. The existing technology still has many shortcomings.

[0003] Currently, independent detection methods are usually used for the detection of impurities in candesartan cilexetil and amlodipine besylate. These methods are mainly targeted at a single component and cannot achieve simultaneous detection of two components and their impurities in a compound preparation. This method has the following disadvantages:

[0004] Low detection efficiency: The two components in the compound preparation need to be tested separately. The operation process is complicated and time-consuming, and cannot meet the needs of rapid detection and high-throughput analysis.

[0005] High cost: The detection of different components requires the use of different instruments, mobile phases and chromatographic columns, which increases the experimental cost.

[0006] Inconsistent results: Due to differences in testing conditions and methods, the test results of different ingredients may lack consistency, affecting the evaluation of the overall quality of the compound preparation.

[0007] Impurities in candesartan cilexetil and amlodipine besylate combination drugs come from a wide range of sources, including:

[0008] Impurities in API process: Unreacted intermediates, by-products or catalyst residues may be produced during the synthesis of API. These impurities exist in trace amounts in the final product, but may have potential effects on drug safety and stability.

[0009] Degradation impurities: The two main components may degrade during storage and use due to the influence of light, humidity, temperature and other factors, generating new impurities.

[0010] Impurities introduced by the formulation process: During the preparation of compound drugs, chemical reactions may occur between the excipients and the main drug, further increasing the types and quantities of impurities.

[0011] Existing detection methods mostly focus on routine impurity detection of single ingredients, which is difficult to comprehensively cover all impurities that may appear in compound preparations, especially the insufficient sensitive detection capability for specific impurities in compound preparations.

[0012] Candesartan cilexetil and amlodipine besylate have significant differences in chemical structure and physicochemical properties, which puts higher requirements on the simultaneous separation and detection of their impurities:

[0013] Difficult to separate: The two components and their impurities may produce overlapping peaks or tailing under chromatographic conditions, resulting in inaccurate quantification.

[0014] Insufficient sensitivity: Existing detection methods have low sensitivity to trace impurities and cannot meet the requirements of high-precision analysis.

[0015] Poor method stability: Due to the complexity of compound preparations, existing methods have certain deficiencies in repeatability and stability, especially in different batches of samples and under complex storage conditions.

[0016] High-performance liquid chromatography (HPLC): Current HPLC methods are mostly developed for single ingredients and cannot adapt to the simultaneous detection of two ingredients in compound preparations. For example, some literature proposes the use of a specific mobile phase to detect candesartan cilexetil impurities, but this method cannot effectively separate amlodipine besylate and its impurities.

[0017] Insufficient optimization of gradient elution: The detection of compound preparations requires the separation of two components and their impurities under the same gradient elution conditions. However, most existing studies have failed to provide an optimized gradient elution scheme, making it difficult for the test results to cover both main components and impurities at the same time.

[0018] Insufficient impurity standard control: The development of standard reference substances for candesartan cilexetil and amlodipine besylate impurities is still incomplete, which limits the promotion and application of the detection method.

[0019] With the improvement of drug quality standards and increasingly stringent regulatory requirements, the development of an efficient and accurate simultaneous detection method has become a key requirement for the quality control of compound preparations. The ideal detection method should meet the following characteristics:

[0020] Simultaneous detection capability: Ability to simultaneously separate and detect candesartan cilexetil, amlodipine besylate and their impurities under single analytical conditions, reducing detection steps and improving detection efficiency.

[0021] High sensitivity and high precision: can accurately identify and quantify trace impurities to meet the requirements of drug safety assessment.

[0022] Strong stability and repeatability: Good separation effect and accuracy can be maintained in different batches and under different conditions.

[0023] Economical and efficient: Simplify experimental operation, reduce detection costs, and be suitable for industrial production conditions.

[0024] In summary, the prior art still has many deficiencies in detection efficiency, sensitivity, coverage and stability, and an optimized synchronous detection method is urgently needed to better meet the quality control requirements of compound preparations. In view of the defects of the prior art, the present invention develops a synchronous detection method for impurities in candesartan cilexetil and amlodipine besylate. Summary of the invention

[0025] The invention provides a synchronous detection method for impurities contained in candesartan cilexetil and amlodipine besylate, so as to solve the defects in the prior art.

[0026] On the one hand, the present invention provides a method for synchronous detection of impurities in candesartan cilexetil and amlodipine besylate, the method comprising the following steps:

[0027] Prepare the test solution by dispersing the fine powder of the compound drug of candesartan cilexetil and amlodipine besylate (such as obtained by grinding the tablets) in the diluent, ultrasonically treat for 10 minutes, and then centrifuge to take the supernatant as the test solution;

[0028] An octadecylsilane bonded silica gel column was used as the chromatographic column;

[0029] A mixed solution of water-acetonitrile-trifluoroacetic acid was used as mobile phase A, and a mixed solution of acetonitrile-water-trifluoroacetic acid was used as mobile phase B;

[0030] Set the detection wavelengths to 240 nm and 253 nm, the flow rate to 1.0 mL / min, and the column temperature to 30 °C;

[0031] The analysis was performed according to the following gradient elution program:

[0032] Time 0 min, mobile phase A is 100%, mobile phase B is 0%;

[0033] Time 15 minutes, mobile phase A is 50%, mobile phase B is 50%;

[0034] time 50 min, mobile phase A 0%, mobile phase B 100%;

[0035] Time 60 min, mobile phase A 0%, mobile phase B 100%;

[0036] Time 60.01 min, mobile phase A 100%, mobile phase B 0%;

[0037] The time was 70 minutes, the mobile phase A was 100%, and the mobile phase B was 0%.

[0038] On the other hand, the preparation method of the diluent comprises:

[0039] Add 3.5 mL of triethylamine to 500 mL of water;

[0040] Adjust the pH of the solution to 3.0 with phosphoric acid;

[0041] Take 400 mL of the above solution, add 450 mL of acetonitrile and 150 mL of methanol, mix well and set aside.

[0042] On the other hand, the steps for preparing the test solution specifically include:

[0043] Accurately weigh 260 mg of compound drug fine powder, which contains 16 mg of candesartan cilexetil and 10 mg of amlodipine besylate;

[0044] Add appropriate amount of diluent and shake to disperse;

[0045] After ultrasonic treatment for 10 minutes, the volume was adjusted to the mark with diluent;

[0046] Centrifuge at 10,000 rpm for 5 min and take the supernatant as the test solution.

[0047] On the other hand, the impurity content of amlodipine besylate is detected at a wavelength of 240 nm, and the impurity content of candesartan cilexetil is detected at a wavelength of 253 nm; the separation R value between the impurity peak and the main peak is greater than 1.5.

[0048] On the other hand, the impurities of candesartan cilexetil include process impurities and degradation impurities, specifically including impurities A, B, C, D, E, F, G, H, and I; the impurities of amlodipine besylate include process impurities and degradation impurities, specifically including impurities A, B, C, D, E, F, G, and H.

[0049] On the other hand, the detection limit of the candesartan cilexetil impurity is no more than 0.1%, and the lower limit of quantification is 0.05%; the detection limit of the amlodipine besylate impurity is no more than 0.1%, and the lower limit of quantification is 0.05%.

[0050] On the other hand, in the analytical method, the concentration range of the impurity reference substance for drawing the standard curve is 0.05 μg / mL to 10 μg / mL, and the linear fitting method is used to calculate the relevant impurity content.

[0051] On the other hand, the separation R value of the method is greater than 1.5, and the relative standard deviation (RSD) of the analysis result is less than 2%, which has good repeatability.

[0052] On the other hand, the total analysis time of the method does not exceed 70 minutes, which can significantly improve the analysis efficiency and is suitable for the quality control of compound preparations under industrial production conditions.

[0053] On the other hand, the method is applicable to tablets, capsules or other solid preparations containing candesartan cilexetil and amlodipine besylate, and is particularly applicable to product quality control in compound pharmaceutical preparations with a main drug content ranging from 1 mg to 100 mg.

[0054] Beneficial effects: The present invention realizes the simultaneous detection of candesartan cilexetil and amlodipine besylate and their impurities, avoiding the cumbersome operation of separately detecting the two components in the traditional method. The optimized detection conditions have high sensitivity, the impurity detection limit does not exceed 0.1%, and the quantitative lower limit is 0.05%. It can accurately identify and quantify low-concentration impurities, greatly improving the detection efficiency and accuracy.

[0055] By optimizing the gradient elution conditions, the separation R values ​​of candesartan cilexetil, amlodipine besylate and their impurities were all greater than 1.5, ensuring the reliability of the test data. The method showed good repeatability and stability under different batches of samples, storage conditions (such as high temperature and high humidity) and a variety of main drug content ranges (1 mg to 100 mg), and the relative standard deviation (RSD) was less than 2%, which is suitable for quality control under industrial conditions.

[0056] This method is applicable to the quality inspection of candesartan cilexetil and amlodipine besylate compound preparations (including tablets, capsules, etc.), and covers the comprehensive inspection of process impurities and degradation impurities. The simplified operation process and reduced requirements for reagents and equipment not only save the inspection cost, but also improve the inspection efficiency of laboratories and industrial production, providing scientific support for the improvement of the quality standards of compound preparations and the standardization of the industry, and has broad application prospects and significant economic value. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] The specific implementation of the present invention is described in detail below in conjunction with multiple embodiments.

[0059] Example 1: Detection of candesartan cilexetil and amlodipine besylate impurities in conventional samples;

[0060] Preparation of test solution:

[0061] Weigh 260 mg of candesartan cilexetil and amlodipine besylate compound tablets (containing 16 mg of candesartan cilexetil and 10 mg of amlodipine besylate), add an appropriate amount of diluent, shake to disperse and ultrasonicate for 10 minutes, make up to 20 mL with diluent, centrifuge (10000 rpm, 5 minutes), and take the supernatant.

[0062] Chromatographic conditions:

[0063] Chromatographic column: octadecylsilane bonded silica gel column;

[0064] Mobile phase: A (water-acetonitrile-trifluoroacetic acid, 4000:1000:1), B (acetonitrile-water-trifluoroacetic acid, 4750:250:1);

[0065] Flow rate: 1.0 mL / min; column temperature: 30°C; detection wavelength: 240 nm (amlodipine besylate), 253 nm (candesartan cilexetil);

[0066] Gradient elution: time 0 min, A 100%, B 0%; 15 min, A 50%, B 50%; 50 min, A 0%, B 100%; 60 min, A 0%, B 100%; 60.01 min, A 100%, B 0%; 70 min, A 100%, B 0%.

[0067] Result analysis: The total impurity content of amlodipine besylate was 0.07%, which was lower than the prescribed limit;

[0068] The total impurity content of candesartan cilexetil is 0.06%, which meets the quality standards.

[0069] Example 2: Effect of different dilutions on detection results;

[0070] Preparation of diluent: Preparation A: Add 3.5 mL of triethylamine to 500 mL of water, adjust the pH to 3.0 with phosphoric acid, take 400 mL of the solution, add 450 mL of acetonitrile and 150 mL of methanol;

[0071] Preparation B: only water-acetonitrile (1:1) was used;

[0072] Preparation scheme C: pure methanol is used as the solvent.

[0073] Test solution detection: The test solution was prepared with the same tablet sample (260 mg), and the diluents of Schemes A, B, and C were used respectively, and the test was carried out according to the chromatographic conditions of Example 1.

[0074] Result analysis:

[0075] Scheme A has the best separation, and the separation R value between the impurity peak and the main peak is >1.5;

[0076] In scheme B, tailing of the main peak occurs, which affects the quantitative accuracy;

[0077] In scheme C, the impurity peak overlaps with the main peak, resulting in poor separation effect.

[0078] Example 3: Detection of high and low content compound tablets;

[0079] Sample source: Preparation of compound tablets with different contents:

[0080] Sample 1: candesartan cilexetil 8 mg, amlodipine besylate 5 mg;

[0081] Sample 2: candesartan cilexetil 16 mg, amlodipine besylate 10 mg;

[0082] Sample 3: candesartan cilexetil 32 mg, amlodipine besylate 20 mg.

[0083] Detection method: Referring to the test solution preparation method and chromatographic conditions of Example 1, the impurity content in the three samples was detected.

[0084] Result analysis: Sample 1: The total impurity content of candesartan cilexetil was 0.08%, and the total impurity content of amlodipine besylate was 0.05%;

[0085] Sample 2: The total impurity content of candesartan cilexetil was 0.06%, and the total impurity content of amlodipine besylate was 0.07%;

[0086] Sample 3: The total impurity content of candesartan cilexetil is 0.09%, and the total impurity content of amlodipine besylate is 0.08%.

[0087] The results showed that this method was applicable to different main drug concentration ranges.

[0088] Example 4: Spike recovery test;

[0089] Experimental design: Known amounts of candesartan cilexetil impurity A and amlodipine besylate impurity B were added to the tablets, and the impurity concentrations were 0.05%, 0.1%, and 0.2%, respectively.

[0090] Detection steps: Referring to the test solution preparation and chromatographic conditions of Example 1, the recovery rate of impurities in the spiked sample was detected.

[0091] Result analysis:

[0092] The recovery rate of impurity A is 98.5%-101.2%;

[0093] The recovery rate of impurity B is 99.0%-100.8%.

[0094] The recovery rate was in line with the methodological requirements (95%-105%), verifying the accuracy of the method.

[0095] Example 5: Long-term stability test;

[0096] Experimental design: Tablet samples were placed at room temperature (25°C), high temperature (40°C), and high humidity (75% RH) for 1, 3, and 6 months, respectively, and the impurity content was regularly tested during this period.

[0097] Testing method: Samples were taken every other month and tested according to the conditions of Example 1.

[0098] Result analysis: The impurities did not change significantly within 6 months at room temperature, and the total impurity content remained below 0.08%;

[0099] Under high temperature and high humidity conditions, the total amount of impurities increased to 0.12% and 0.15% respectively after 6 months, and the formation of impurities C and impurity D was more obvious.

[0100] The results showed that this method is suitable for long-term stability study.

[0101] Example 6: Industrial production scale sample testing

[0102] Sample source

[0103] Take batch samples of industrially produced compound tablets and randomly select 10 tablets from each batch for testing.

[0104] Detection steps: Prepare the test solution and detect the impurity content of each batch of samples according to the chromatographic conditions of Example 1.

[0105] Result analysis: The impurity content of candesartan cilexetil and amlodipine besylate in each batch of samples was less than 0.1%, and the main peak separation R value was greater than 1.5;

[0106] This method is suitable for quality control on an industrial scale.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for synchronously detecting impurities in candesartan cilexetil and amlodipine besylate, characterized in that: The method comprises the following steps: Prepare the test solution by dispersing the fine powder of candesartan cilexetil and amlodipine besylate in the diluent, ultrasonically treat for 10 minutes, and then centrifuge to take the supernatant as the test solution; An octadecylsilane bonded silica gel column was used as the chromatographic column; A mixed solution of water-acetonitrile-trifluoroacetic acid was used as mobile phase A, and a mixed solution of acetonitrile-water-trifluoroacetic acid was used as mobile phase B; Set the detection wavelengths to 240 nm and 253 nm, the flow rate to 1.0 mL / min, and the column temperature to 30 °C; The analysis was performed according to the following gradient elution program: Time 0 min, mobile phase A is 100%, mobile phase B is 0%; Time 15 minutes, mobile phase A is 50%, mobile phase B is 50%; time 50 min, mobile phase A 0%, mobile phase B 100%; Time 60 min, mobile phase A 0%, mobile phase B 100%; Time 60.01 min, mobile phase A 100%, mobile phase B 0%; The time was 70 minutes, the mobile phase A was 100%, and the mobile phase B was 0%.

2. The method for simultaneous detection of impurities in candesartan cilexetil and amlodipine besylate according to claim 1, characterized in that: The preparation method of the diluent comprises: Add 3.5 mL of triethylamine to 500 mL of water; Adjust the pH of the solution to 3.0 with phosphoric acid; Take 400 mL of the above solution, add 450 mL of acetonitrile and 150 mL of methanol, mix well and set aside.

3. The method for simultaneous detection of impurities in candesartan cilexetil and amlodipine besylate according to claim 1, characterized in that: The steps for preparing the test solution specifically include: Accurately weigh 260 mg of compound drug fine powder, which contains 16 mg of candesartan cilexetil and 10 mg of amlodipine besylate; Add appropriate amount of diluent and shake to disperse; After ultrasonic treatment for 10 minutes, the volume was adjusted to the mark with diluent; Centrifuge at 10,000 rpm for 5 min and take the supernatant as the test solution.

4. The method for simultaneous detection of impurities in candesartan cilexetil and amlodipine besylate according to claim 1, characterized in that: The impurity content of amlodipine besylate is detected at a wavelength of 240 nm, and the impurity content of candesartan cilexetil is detected at a wavelength of 253 nm; the separation R value between the impurity peak and the main peak is greater than 1.

5.

5. The method for simultaneous detection of impurities in candesartan cilexetil and amlodipine besylate according to claim 1, characterized in that: The candesartan cilexetil impurities include process impurities and degradation impurities, specifically including impurities A, B, C, D, E, F, G, H, and I; the amlodipine besylate impurities include process impurities and degradation impurities, specifically including impurities A, B, C, D, E, F, G, and H.

6. The method for simultaneous detection of impurities in candesartan cilexetil and amlodipine besylate according to claim 1, characterized in that: The detection limit of the candesartan cilexetil impurity is no more than 0.1%, and the lower limit of quantification is 0.05%; the detection limit of the amlodipine besylate impurity is no more than 0.1%, and the lower limit of quantification is 0.05%.

7. The method for simultaneous detection of impurities in candesartan cilexetil and amlodipine besylate according to claim 1, characterized in that: In the analytical method, the concentration range of the impurity reference substance for drawing the standard curve is 0.05 μg / mL to 10 μg / mL, and the linear fitting method is used to calculate the relevant impurity content.

8. The method for simultaneous detection of impurities in candesartan cilexetil and amlodipine besylate according to claim 1, characterized in that: The separation R value of this method is greater than 1.5, and the relative standard deviation (RSD) of the analysis result is less than 2%, which has good repeatability.

9. The method for simultaneous detection of impurities in candesartan cilexetil and amlodipine besylate according to claim 1, characterized in that: The total analysis time of the method does not exceed 70 minutes, which can significantly improve the analysis efficiency and is suitable for the quality control of compound preparations under industrial production conditions.

10. The method for simultaneous detection of impurities in candesartan cilexetil and amlodipine besylate according to claim 1, characterized in that: The method is applicable to tablets, capsules or other solid preparations containing candesartan cilexetil and amlodipine besylate, and is particularly applicable to product quality control in compound pharmaceutical preparations with a main drug content ranging from 1 mg to 100 mg.