Method for detecting content of isomer impurities in sacubitril-valsartan sodium tablet

Abstract

The invention provides a method for detecting the content of stereoisomer impurities in sacubitril-valsartan sodium tablets by adopting a high performance liquid chromatography. Chromatographic conditions are as follows: Chiralcel OJ-RH, 150 * 4.6 mm, 5 [mu] m chromatographic columns and an ultraviolet detector are adopted, the detection wavelength is 254 nm, the column temperature is 35 DEG C, the flow rate is 0.75 ml / min, and the sample injection volume is 20 [mu] l. Gradient elution is adopted, and a mobile phase A is a mixed solution of water, acetonitrile and trifluoroacetic acid in a ratio of 800: 200: 1; and the mobile phase B is a mixed solution of acetonitrile and methanol in a ratio of 450: 550.

Description

Technical Field

[0001] The present invention relates to the field of pharmaceutical analysis, and particularly to a method for detecting the content of isomeric impurities in sacubitril / valsartan sodium tablets. Background Art

[0002] Sacubitril / valsartan sodium tablets are a compound drug developed by Novartis for the treatment of chronic heart failure with reduced ejection fraction, and its composition is a sodium hydrate composed of sacubitril and valsartan. Both sacubitril and valsartan in sacubitril / valsartan sodium are compounds with asymmetric centers, and their structures are as follows: Among them, there is 1 chiral center on the valine residue part of valsartan, and its enantiomer is: There are 2 chiral centers at positions 2 and 4 of sacubitril, and its enantiomers and diastereomers are: These isomeric impurities may come from unseparated isomeric impurities in intermediate production, or may be generated due to improper storage or unreasonable processes in the preparation. Such isomeric impurities may be difficult to completely remove due to their similar properties, resulting in residues in the product. According to the relevant records in ICH M7, generally for a single impurity without special genotoxicity, its identification limit is 0.1%, and the total impurity content should be less than 1%. In view of the existence of the above-mentioned various isomeric impurities, a dedicated method is needed to detect the content of isomers in sacubitril / valsartan sodium preparations to meet the requirements of drug quality control. Summary of the Invention

[0003] Based on the above technical background, we provide a method for detecting isomeric impurities in sacubitril / valsartan sodium preparations in the present invention, wherein the isomeric impurities include valsartan isomers and sacubitril isomers 1-3, and their structures are as follows;

[0004] The specific content includes the following steps: (1) Solution preparation Diluent: water - acetonitrile (50:50); Blank solution: water - acetonitrile (50:50); Valsartan isomer stock solution: Take about 12.5 mg of valsartan isomer reference substance, accurately weigh it, place it in a 50 ml volumetric flask, dissolve it with methanol and dilute to the scale, shake well, then accurately measure 5 ml, place it in a 50 ml volumetric flask, and dilute to the scale with the diluent, shake well.

[0005] Sacubitril Isomer Reference Stock Solution: Weigh accurately about 14 mg of each of the sacubitril isomer 1 - 3 reference substances, place them in the same 50 ml volumetric flask, dissolve with the diluent and dilute to the mark, then shake well. Pipette accurately 5 ml of the above solution, place it in a 50 ml volumetric flask, dilute to the mark with the diluent, and shake well.

[0006] Reference Solution: Pipette accurately 5 ml of the valsartan isomer stock solution and 1 ml of the sacubitril isomer reference stock solution, place them in a 50 ml volumetric flask, dilute to the mark with the diluent, and shake well.

[0007] Test Solution: Take the sacubitril valsartan sodium tablets, place them in a volumetric flask, add purified water, let it stand for 30 minutes, then sonicate for 5 minutes until the tablets are completely disintegrated. Add an appropriate amount of diluent, sonicate for about 5 minutes to dissolve, dilute to the mark with the diluent, shake well, and centrifuge to obtain the test stock solution. Then pipette accurately 5 ml, place it in a 100 ml volumetric flask, dilute to the mark with the diluent, and shake well.

[0008] System Suitability Solution: Pipette accurately 2.5 ml of the test stock solution, place it in a 50 ml volumetric flask. Take 5 ml of the valsartan isomer stock solution and 1 ml of the sacubitril isomer reference stock solution, place them in this flask, dilute to the mark with the diluent, and shake well.

[0009] (2) Inject the reference solution and the test solution into the ultra - high performance liquid chromatograph respectively, and record the chromatograms. The chromatographic conditions are as follows: Chromatographic column: Daicel Corporation, Chiralcel OJ - RH, 150×4.6 mm, 5 μm; Detection wavelength: 254 nm; Column temperature: 35 °C; Flow rate: 0.75 ml / min; Injection volume: 20 μl; Gradient elution is adopted. Mobile phase A: water - acetonitrile - trifluoroacetic acid = 800:200:1; Mobile phase B: acetonitrile - methanol = 450:550.

[0010] The elution gradient is as follows:

[0011] After the system is stable, inject 6 needles of the reference solution and 1 needle of the test solution, record the chromatograms, and calculate the results according to the following formula: Isomer Content (%) =

[0012] Where: A S — Peak area of the isomer in the test solution; N s — Dilution factor of the test solution; M R — Sampling amount (mg) of each isomer of the reference substance; CR — Content of each isomer of the reference substance; A R — Average peak area of each isomer in the reference substance solution; N R — Dilution factor of the isomer in the reference substance solution; Q — Labeled content (mg / tablet) of sacubitril / valsartan in this product; The solution provided by the present invention provides a method for detecting valsartan isomers and sacubitril isomers in sacubitril / valsartan sodium preparations by high performance liquid chromatography using an octadecylsilane-bonded silica column, with high detection sensitivity. The method has passed the validation experiment, and the validation results show that the system suitability, specificity, etc. of this method meet the requirements. Specific embodiments

[0013] The present invention is further illustrated by the following examples, but is not limited to the present invention. Example 1

[0014] System suitability Solution preparation

[0015] The chromatographic conditions are as follows: chromatographic column: Daicel Corporation, Chiralcel OJ-RH, 150×4.6mm, 5μm, detection wavelength: 254nm, column temperature: 35°C, flow rate: 0.75ml / min, injection volume: 20μl; gradient elution is used, mobile phase A: water - acetonitrile - trifluoroacetic acid = 800:200:1; mobile phase B: acetonitrile - methanol = 450:550.

[0016] The elution gradient is:

[0017] Example 2

[0018] Specificity Solution preparation

[0019] The valsartan isomer stock solution, sacubitril isomer 1 reference substance stock solution, sacubitril isomer 2 reference substance stock solution, sacubitril isomer 3 stock solution, mixed reference substance stock solution, reference substance solution, and system suitability solution used are the same as in Example 1; the chromatographic conditions are the same as in Example 1;

[0020] Example 3

[0021] Quantitation Limit and Detection Limit Solution Preparation

[0022] The chromatographic conditions are the same as those in Example 1;

[0023] The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for detecting the content of isomeric impurities in sacubitril / valsartan sodium tablets, characterized in that, The isomeric impurities include valsartan isomers and sacubitril isomers. The valsartan isomers are the enantiomers of valsartan, and the sacubitril isomers are the enantiomers and diastereoisomers of sacubitril, including the following steps: (1) Solution preparation: Take the valsartan sacubitril sodium tablets to be tested, add water for disintegration, and dilute with 50% aqueous acetonitrile solution to obtain the test solution; (2) Inject the test solution into a high performance liquid chromatograph. The chromatographic conditions are as follows: chromatographic column: Daicel Corporation, Chiralcel OJ-RH, 150×4.6 mm, 5 μm; detection wavelength: 254 nm; column temperature: 35°C; flow rate: 0.75 ml / min; injection volume: 20 μl; gradient elution is adopted. Mobile phase A is a solution prepared by mixing water, acetonitrile and trifluoroacetic acid in a volume ratio of 800:200:1; mobile phase B is a solution prepared by mixing acetonitrile and methanol in a volume ratio of 450:

550.

2. The method according to claim 1, characterized in that, The elution gradient of the gradient elution is as follows: 。

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