A method for detecting 2-aminothiazole and D-7-ACA lactone, impurities in ceftriaxone sodium and its preparation

Abstract

The application discloses a method for detecting 2-aminothiazole and D-7-ACA lactone impurities in ceftriaxone sodium and a preparation thereof, and relates to the technical field of medicine detection. The method is detected by using high performance liquid chromatography-mass spectrometry, and comprises the following steps: preparing 2-aminothiazole and D-7-ACA lactone control solution and sample solution; sample injection detection: the chromatographic column is a Capcell PAK C18 AQ, 4.6*150mm, 3um; the mobile phase A is 0.005M ammonium formate-0.05% formic acid aqueous solution, and the mobile phase B is acetonitrile, gradient elution is carried out; the injection volume is 20ul, the flow rate is 1.0ml / min, and the column temperature is 40 DEG C. The method can qualitatively and quantitatively detect the possible 2-aminothiazole and D-7-ACA lactone impurities in ceftriaxone sodium and a preparation thereof, has good specificity, low quantitative limit, high sensitivity, high accuracy, good anti-interference, and can meet the detection requirements of ceftriaxone sodium.

Description

Technical Field

[0001] This invention relates to the field of pharmaceutical testing technology, and in particular to a method for detecting impurities 2-aminothiazole and D-7-ACA lactone in ceftriaxone sodium and its preparations. Background Technology

[0002] Ceftriaxone sodium is a type of cephalosporin that exerts its bactericidal activity by inhibiting bacterial cell wall synthesis. Ceftriaxone exhibits bactericidal activity against many Gram-negative and Gram-positive bacteria in vitro and demonstrates high stability against most β-lactamases (penicillinases and cephalosporinases) of both Gram-positive and Gram-negative bacteria.

[0003] Under alkaline conditions, the carbon-carbon bond at position 4 of the ceftriaxone thiazole group breaks to generate 2-aminothiazole, which has a warning structure. The Derek Nexus Report predicts a negative result, while the Sarah Nexus Report predicts a positive result.

[0004] D-7-ACA lactone may be generated during the synthesis of 7-aminocephalosporanic acid, an important raw material for the synthesis of ceftriaxone sodium. D-7-ACA lactone may be transferred to ceftriaxone sodium and may remain in the sodium. D-7-ACA lactone contains a warning structure; the Derek Nexus Report prediction result is negative, and the Sarah Nexus Report prediction result is uncertain.

[0005]

[0006] To ensure product quality, research and control are required in ceftriaxone sodium. First, qualitative and quantitative detection of 2-aminothiazole and D-7-ACA lactone in ceftriaxone sodium is necessary.

[0007] The maximum daily dose of ceftriaxone sodium for injection is 4g. Based on ICH M7 guidelines, the limits for 2-aminothiazole and D-7-ACA lactone are calculated as follows: Impurity limit = (1.5μg / day) / (4g / day) × 10 6 ≈0.375ppm; low impurity limit.

[0008] Due to the low limits of impurities and weak ultraviolet absorption, conventional HPLC-UV methods are difficult to use and have poor specificity. Therefore, it is necessary to study a highly sensitive, specific, and anti-interference method that can simultaneously perform qualitative and quantitative detection of the impurities 2-aminothiazole and D-7-ACA lactone in ceftriaxone sodium. Summary of the Invention

[0009] To address the above shortcomings, this invention provides a method for detecting the impurities 2-aminothiazole and D-7-ACA lactone in ceftriaxone sodium and its preparations. This method features high detection sensitivity, strong specificity, and strong anti-interference ability, enabling qualitative and quantitative detection of the impurities 2-aminothiazole and D-7-ACA lactone in ceftriaxone sodium and its preparations. The specific technical solution is as follows: A method for detecting impurities 2-aminothiazole and D-7-ACA lactone in ceftriaxone sodium and its preparations, using high performance liquid chromatography-mass spectrometry (HPLC-MS), includes the following steps: (1) Preparation of reference solutions of 2-aminothiazole and D-7-ACA lactone; (2) Preparation of test solution: Take the ceftriaxone sodium test sample to be tested, add ultrapure water to dissolve it, and prepare the test solution; (3) Set chromatographic conditions: Column: AQ column, 4.6×150mm, 3μm; Mobile phase A is 0.005M formate-0.05% formic acid aqueous solution, mobile phase B is methanol or acetonitrile, injection volume is 10~20μl, flow rate is 0.9~1.2ml / min, column temperature is 35~45℃; The elution gradient is:

[0010] Preferably, the elution gradient is:

[0011] (4) Set the mass spectrometry conditions; (5) Injection detection: Take the reference solution and the test solution, inject them for analysis, and record the chromatogram. When the chromatogram of the test solution has the same retention time as that of 2-aminothiazole and D-7-ACA lactone in the reference solution, it indicates that it contains 2-aminothiazole and D-7-ACA lactone. The content of impurities 2-aminothiazole and D-7-ACA lactone can be calculated by peak area according to the external standard method.

[0012] Preferably, in step (1), the reference solution is prepared by weighing 2-aminothiazole and D-7-ACA lactone reference standards respectively, dissolving them in ultrapure water to prepare a solution containing 10 ng of 2-aminothiazole and D-7-ACA lactone per 1 ml, which is used as the reference solution.

[0013] Preferably, in step (2), the test solution is prepared by accurately weighing 250-300 mg of the ceftriaxone sodium test sample to be tested, placing it in a 10 ml volumetric flask, adding ultrapure water to dissolve and dilute to the mark, and shaking well to obtain the test solution.

[0014] Preferably, in step (3), the AQ column is Shiseido Capcell PAK C18 AQ.

[0015] Preferably, in step (3), the mobile phase A is 0.005M ammonium formate-0.05% formic acid aqueous solution, the mobile phase B is acetonitrile, the injection volume is 20 μl, the flow rate is 1.0 ml / min, and the column temperature is 40℃.

[0016] Preferably, in step (4), the mass spectrometry conditions are: SIM mode, positive ion mode; SIM ions: 2-aminothiazole 101.0, D-7-ACA lactone 213.1; collision-induced dissociation: 2-aminothiazole 85~90, D-7-ACA lactone 90~100; split flow rate into the mass spectrometer detector: 0.1~0.2 ml / min; drying gas flow rate: 5~13 L / min; drying gas temperature: 320~350℃; nebulizing gas pressure: 1039~2599 Torr; capillary voltage: 1900~2100 V.

[0017] Preferably, in step (4), the mass spectrometry conditions are: SIM mode, positive ion mode; SIM ions: 2-aminothiazole 101.0, D-7-ACA lactone 213.1; collision-induced dissociation: 2-aminothiazole 90, D-7-ACA lactone 95; drying gas flow rate: 12 L / min, drying gas temperature: 350℃, nebulizing gas pressure: 1811 Torr, capillary voltage: 2000 V.

[0018] Preferably, in step (5), the contents of impurities 2-aminothiazole and D-7-ACA lactone are calculated by peak area using the external standard method, and the calculation formula is as follows: In the formula: W S W T Weigh the reference standard and test sample (mg) respectively; D S D T These are the dilution factors for the reference standard and the test sample, respectively; A S A T These represent the peak areas of the reference standard and the test sample, respectively; P represents the purity of the reference standard.

[0019] The present invention also provides a method for detecting impurities 2-aminothiazole and D-7-ACA lactone in ceftriaxone sodium and its preparations, and its application in the quality control of ceftriaxone sodium and its preparations.

[0020] Compared with the prior art, the beneficial effects of the present invention are: This invention utilizes 0.005M formate-0.05% formic acid aqueous solution and acetonitrile as the mobile phase, and optimizes the elution program to achieve qualitative and quantitative detection of the impurities 2-aminothiazole and D-7-ACA lactone in ceftriaxone sodium. The method exhibits good specificity, low detection limit, high sensitivity, and high accuracy (recoveries of 99.38% and 101.69%, respectively). Furthermore, even with minor changes in column temperature, collision-induced dissociation, and capillary voltage, the recoveries of 2-aminothiazole and D-7-ACA lactone show minimal difference compared to results obtained under the basic conditions, demonstrating good robustness. In addition, the regression equations for the peak areas of 2-aminothiazole and D-7-ACA lactone and their concentrations show a linear correlation with good linearity, making the method convenient to use. This detection method can effectively control drug quality, reduce potential adverse reactions in clinical trials and treatment, and ensure the efficacy and safety of medication for patients. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 The detection spectrum is for the blank solution; Figure 2 The detection chromatogram of D-7-ACA lactone localization solution; Figure 3 The detection chromatogram for 2-aminothiazolinone localization solution; Figure 4 The detection chromatogram of the test solution; Figure 5 The detection chromatogram for the reference solution; Figure 6 This is a standard curve for 2-aminothiazole. Figure 7 This is a standard curve of D-7-ACA lactone. Detailed Implementation

[0023] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. Unless otherwise defined, all technical terms used below have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the scope of protection of the present invention. Unless otherwise specifically stated, all raw materials, reagents, instruments, and equipment used in the present invention are commercially available or can be prepared by existing methods.

[0024] The instruments, equipment, and sources of some reagents used in the following specific implementation methods are shown in Table 1.

[0025] Table 1. Models and sources of instruments, consumables and reagents

[0026] Example 1 A method for detecting the impurities 2-aminothiazole and D-7-ACA lactone in ceftriaxone sodium, comprising the following steps: (1) Preparation of solution Preparation of reference stock solution: Weigh 1 mg each of 2-aminothiazole and D-7-ACA lactone reference standards accurately, place them in the same 100 ml volumetric flask, dissolve and dilute to the mark with 50% acetonitrile, and shake well; measure 1 ml, place it in a 100 ml volumetric flask, dilute to the mark with ultrapure water, and shake well to obtain the reference stock solution. Preparation of reference solution: Measure 1 ml of the reference stock solution, place it in a 10 ml volumetric flask, dilute with ultrapure water to the mark, and shake well to obtain the reference solution; Preparation of test solution: Weigh 270 mg of the ceftriaxone sodium test sample to be tested accurately, place it in a 10 ml volumetric flask, add ultrapure water to dissolve and dilute to the mark, and shake well to obtain the test solution; (2) Chromatographic conditions Chromatographic column: Shiseido Capcell Pak C18 AQ, 4.6×150mm, 3μm; mobile phase A was 0.005M ammonium formate-0.05% formic acid aqueous solution, mobile phase B was acetonitrile, injection volume was 20μl, flow rate was 1.0ml / min, column temperature was 40℃; gradient elution program by volume percentage is shown in Table 2; Table 2 Gradient elution program

[0027] Mass spectrometry conditions: SIM mode, positive ion mode; collision-induced dissociation (Fragmentor): SIM Mode: Polarity: Positive SIM ions and collision-induced dissociation (Fragmentor):

[0028] Capillary voltage (VCap): 2000V; Drying gas flow rate: 12.0L / min; Gas temperature: 350℃; Atomizing gas pressure: 1811Torr.

[0029] (3) Chromatographic detection Accurately measure 20 μl each of the reference solution and the test solution, inject them for analysis, and record the chromatograms. If the chromatogram of the test solution shows a peak with the same retention time as 2-aminothiazole and D-7-ACA lactone in the reference solution, it indicates the presence of 2-aminothiazole and D-7-ACA lactone. Calculate the impurity amount based on peak area using the external standard method, as follows: In the formula: W S W T Weigh the reference standard and test sample (mg) respectively; D S D T These are the dilution factors for the reference standard and the test sample, respectively; A S A T These represent the peak areas of the reference standard and the test sample, respectively; P represents the purity of the reference standard.

[0030] The test sample, ceftriaxone sodium, must contain no more than 0.375 ppm of 2-aminothiazole and D-7-ACA lactone.

[0031] Example 2: Specificity Experiment of the Detection Method (1) Preparation of solution D-7-ACA lactone reference standard stock solution: Weigh approximately 1 mg of D-7-ACA lactone reference standard accurately, place it in a 100 ml volumetric flask, add 50% acetonitrile, sonicate to dissolve and dilute to the mark, shake well, and the solution is ready. 2-Aminothiazole reference standard stock solution: Weigh approximately 1 mg of 2-aminothiazole reference standard accurately, place it in a 100 ml volumetric flask, add 50% acetonitrile, sonicate to dissolve and dilute to the mark, shake well to obtain the solution; Reference stock solution: Accurately measure 1 ml each of D-7-ACA lactone reference stock solution and 2-aminothiazole reference stock solution, place them in the same 100 ml volumetric flask, dilute to the mark with diluent, and shake well to obtain the solution.

[0032] Reference solution: Accurately measure 1.0 ml of the mixed reference stock solution, place it in a 10 ml volumetric flask, dilute to the mark with diluent, and shake well to obtain the solution.

[0033] D-7-ACA lactone positioning solution: Accurately measure 1.0 ml of D-7-ACA lactone reference standard stock solution, place it in a 100 ml volumetric flask, dilute to the mark with diluent, and shake well; accurately measure 1.0 ml, place it in a 10 ml volumetric flask, dilute to the mark with diluent, and shake well to obtain the solution.

[0034] 2-Aminothiazole positioning solution: Accurately measure 1.0 ml of 2-aminothiazole reference stock solution, place it in a 100 ml volumetric flask, dilute to the mark with diluent, and shake well; accurately measure 1.0 ml, place it in a 10 ml volumetric flask, dilute to the mark with diluent, and shake well to obtain the solution.

[0035] According to the preparation method of the test solution, accurately weigh 270 mg of ceftriaxone sodium test sample, place it in a 10 ml volumetric flask, add ultrapure water to dissolve and dilute to the mark, and shake well to obtain the test solution.

[0036] Sample loading solution: Weigh 270 mg of ceftriaxone sodium test sample accurately, place it in a 10 ml volumetric flask, add 1 ml of reference stock solution, dissolve and dilute to the mark with ultrapure water, and shake well.

[0037] (2) Chromatographic conditions Same as Example 1.

[0038] (3) Chromatographic detection Take blank solution (ultrapure water), reference solution, D-7-ACA lactone positioning solution, 2-aminothiazole positioning solution, test solution, and spiking solution respectively for detection, and record the chromatograms.

[0039] The results are as follows Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, blank solution, test solution and other impurities do not interfere with the detection of impurities 2-aminothiazole and D-7-ACA lactone, indicating good method specificity.

[0040] Example 3: Limit of Detection and Limit of Quantification Experiment The reference standard stock solution was prepared according to the method described in Example 1. An appropriate amount of the reference standard stock solution was measured and serially diluted with ultrapure water. The limit of quantitation (LOQ) concentration was determined using a signal-to-noise ratio (SNR) ≥ 10. The LQ concentration for 2-aminothiazole was 0.9976 ng / ml, and the LQ concentration for D-7-ACA lactone was 1.0010 ng / ml. The method's LQ met the requirements. An appropriate amount of the reference standard stock solution was measured and serially diluted with ultrapure water. The limit of detection (LOD) concentration was determined using a SNR ≥ 3. The LOD concentration for 2-aminothiazole was 0.499 ng / ml, and the LOD concentration for D-7-ACA lactone was 0.500 ng / ml. The detection limits were low, indicating high method sensitivity.

[0041] Example 4: Linear Methodology Experiment of the Detection Method (1) Preparation of solution The reference standard stock solution was prepared according to the method for preparing the reference standard stock solution in Example 1.

[0042] Accurately measure 0.3 ml, 0.5 ml, 1.0 ml, 1.5 ml, and 2.0 ml of the reference standard stock solution and place them in 10 ml volumetric flasks respectively. Dilute to the mark with diluent and shake well to obtain 30%, 50%, 100%, 150%, and 200% linear solutions.

[0043] Prepare linear solutions at the specified limit level according to the limit of quantitation solution method in Example 3.

[0044] (2) Chromatographic conditions Same as Example 1.

[0045] (3) Chromatographic detection Linear solutions at different concentration levels were tested, and linear regression analysis was performed with concentration as the x-axis and peak area as the y-axis. The square of the correlation coefficient (R²) of the regression line was calculated. 2 The results are shown in Table 3.

[0046] Table 3 Results of Linearity Study

[0047] The results are as follows Figure 6 , Figure 7 As shown in Table 3, the correlation coefficient R between 2-aminothiazole and D-7-ACA lactone is greater than 0.999, indicating a good linear relationship. The linear range of the impurities is from the limit of quantitation to 200% of the concentration, which meets the detection requirements.

[0048] Example 5 Accuracy Experiment (1) Preparation of solution Recovery experiments were conducted by spiking within 50% to 150% of the limits for 2-aminothiazole and D-7-ACA lactone (0.375 ppm).

[0049] The reference standard stock solution was prepared according to the method for preparing the reference standard stock solution in Example 1.

[0050] Reference solution: Accurately measure 1.0 ml of the reference stock solution, place it in a 10 ml volumetric flask, dilute to the mark with diluent, and shake well to obtain the solution.

[0051] Sample blank: Weigh approximately 270 mg of ceftriaxone sodium raw material accurately, place it in a 10 ml volumetric flask, add diluent, sonicate to dissolve and dilute to the mark, shake well, and the sample blank is obtained.

[0052] 50% recovery solution: Weigh approximately 270 mg of ceftriaxone sodium raw material and place it in a 10 ml volumetric flask. Add 0.5 ml of the reference stock solution, dissolve and dilute to the mark with diluent, and shake well. Prepare 3 parallel portions.

[0053] 100% recovery solution: Weigh approximately 270 mg of ceftriaxone sodium raw material, place it in a 10 ml volumetric flask, add 1 ml of reference stock solution, dissolve and dilute to the mark with diluent, shake well, and prepare 3 parallel portions.

[0054] 150% recovery solution: Weigh approximately 270 mg of ceftriaxone sodium raw material and place it in a 10 ml volumetric flask. Add 1.5 ml of the reference stock solution, dissolve and dilute to the mark with diluent, and shake well. Prepare 3 parallel portions.

[0055] (2) Chromatographic conditions Same as Example 1.

[0056] (3) Chromatographic detection The reference solution, sample blank, 50% recovery solution, 100% recovery solution, and 150% recovery solution were injected for analysis. The recoveries of 2-aminothiazole and D-7-ACA lactone were calculated, and the results are shown in Table 4.

[0057] Table 4: Accuracy Test Results

[0058] Results: Accuracy tests were conducted by adding reference standards at concentrations of 50%–150% of the limit to the test solution. The average recoveries were 99.38% and 101.69%, respectively, with RSD values ​​less than 8%, indicating good method accuracy.

[0059] Example 6 Precision Experiment (1) Preparation of solution Prepare a repeatable solution according to the method for preparing the 100% recovery solution in Example 4, and prepare 6 replicates.

[0060] (2) Chromatographic conditions Same as Example 1.

[0061] (3) Chromatographic detection Repeated solutions were injected for analysis, and the recoveries of 2-aminothiazole and D-7-ACA lactone were calculated. The results are shown in Table 5.

[0062] Table 5: Recovery Rate Results of Repeatability Tests

[0063] Conclusion: The average recovery rates of the six reproducible solutions were all between 75% and 120%, and the RSD values ​​were all less than 8%, indicating that the method has good reproducibility.

[0064] Example 7 Solution stability experiment (1) Preparation of solution The reference solution was prepared according to the method for preparing the reference solution in Example 1.

[0065] The test sample spiking solution was prepared according to the method for preparing the 100% recovery solution in Example 4.

[0066] (2) Chromatographic conditions Same as Example 1.

[0067] (3) Chromatographic detection Both the reference solution and the test sample solution were tested at 0 h, 2.5 h, 6.5 h, 13.5 h, and 18 h. The RSD values ​​of the peak areas of 2-aminothiazole and D-7-ACA lactone in the reference solution and the RSD values ​​of the changes in the contents of 2-aminothiazole and D-7-ACA lactone in the test sample solution were calculated. The results are shown in Table 6.

[0068] Table 6: Results of Solution Stability Test

[0069] Results: The RSD values ​​of the peak area changes of 2-aminothiazole and D-7-ACA lactone in the reference solution were both less than 10%, and the RSD values ​​of the content changes of 2-aminothiazole and D-7-ACA lactone in the test sample solution were both less than 10%, indicating that the solutions of the reference solution and the test sample solution had good stability within 18 hours at room temperature.

[0070] Example 8 Durability Test (1) Preparation of solution The reference solution was prepared according to the method for preparing the reference solution in Example 1.

[0071] The test sample spiking solution was prepared according to the method for preparing the 100% recovery solution in Example 4.

[0072] Test solution: Accurately weigh 270 mg of the ceftriaxone sodium test sample to be tested, place it in a 10 ml volumetric flask, dissolve and dilute to the mark with ultrapure water, and shake well to obtain the test solution. (2) Chromatographic conditions The standard conditions are the same as in Example 1.

[0073] Experiments were conducted under standard conditions by changing a single variable, namely, column temperature, collision-induced dissociation, and capillary voltage.

[0074] (3) Chromatographic detection Reference solution, test solution and test sample solution were injected and analyzed under different chromatographic conditions. The RSD values ​​of the recoveries of 2-aminothiazole and D-7-ACA lactone were calculated. The results are shown in Table 7.

[0075] Table 7: Durability Test Results

[0076] Results: Under slight changes in chromatographic conditions (column temperature ±5℃, collision-induced dissociation ±5℃, capillary voltage ±100V), the average recoveries of D-7-ACA lactone and 2-aminothiazole in the sample solution were 91.55% and 102.97%, respectively, with RSD values ​​of 5.3% and 2.4%, respectively, both less than 8%, indicating good robustness of the method.

[0077] Example 9: Detection results of impurities 2-aminothiazole and D-7-ACA lactone in ceftriaxone sodium The impurities 2-aminothiazole and D-7-ACA lactone in seven batches of ceftriaxone sodium were detected according to the detection method in Experiment Example 1. The experimental results are shown in Table 8. As can be seen from Table 8, the contents of impurities 2-aminothiazole and D-7-ACA lactone in the seven batches of samples meet the product requirements.

[0078] Table 8. Detection results of impurities 2-aminothiazole and D-7-ACA lactone in ceftriaxone sodium.

[0079] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A method for detecting the impurities 2-aminothiazole and D-7-ACA lactone in ceftriaxone sodium and its preparations, characterized in that, The detection was performed using high-performance liquid chromatography-mass spectrometry (HPLC-MS), including the following steps: (1) Preparation of reference solutions of 2-aminothiazole and D-7-ACA lactone; (2) Preparation of test solution: Take the ceftriaxone sodium test sample to be tested, add ultrapure water to dissolve it, and prepare the test solution; (3) Set chromatographic conditions: Column: AQ column, 4.6×150mm, 3μm; Mobile phase A is 0.005M formate-0.05% formic acid aqueous solution, mobile phase B is methanol or acetonitrile, injection volume is 10~20μl, flow rate is 0.9~1.2ml / min, column temperature is 35~45℃; The gradient elution program was as follows (by volume percentage): 0–1 min, mobile phase A was 100% and mobile phase B was 0%; 1–3 min, mobile phase A decreased from 100% to 95% and mobile phase B decreased from 0% to 5%; 3–8 min, mobile phase A decreased from 95% to 70% and mobile phase B decreased from 5% to 30%; 8–13 min, mobile phase A decreased from 70% to 10% and mobile phase B decreased from 30% to 90%; 13–17 min, mobile phase A remained at 10% and mobile phase B remained at 90%; 17–18 min, mobile phase A decreased from 10% to 100% and mobile phase B decreased from 90% to 0%; 18–23 min, mobile phase A remained at 100% and mobile phase B remained at 0%. (4) Set the mass spectrometry conditions; (5) Injection detection: Take the reference solution and the test solution, inject them for analysis, and record the chromatogram. When the chromatogram of the test solution has the same retention time as that of 2-aminothiazole and D-7-ACA lactone in the reference solution, it indicates that it contains 2-aminothiazole and D-7-ACA lactone. The content of impurities 2-aminothiazole and D-7-ACA lactone can be calculated by peak area according to the external standard method.

2. The method for detecting impurities 2-aminothiazole and D-7-ACA lactone in ceftriaxone sodium and its preparations according to claim 1, characterized in that, In step (1), the reference solution is prepared by weighing 2-aminothiazole and D-7-ACA lactone reference standards respectively, dissolving them in ultrapure water to prepare a solution containing 10 ng of 2-aminothiazole and D-7-ACA lactone per 1 ml, which is used as the reference solution.

3. The method for detecting impurities 2-aminothiazole and D-7-ACA lactone in ceftriaxone sodium and its preparations according to claim 1, characterized in that, In step (2), the test solution is prepared by accurately weighing 250-300 mg of the ceftriaxone sodium test sample to be tested, placing it in a 10 ml volumetric flask, adding ultrapure water to dissolve and dilute to the mark, and shaking well to obtain the test solution.

4. The method for detecting impurities 2-aminothiazole and D-7-ACA lactone in ceftriaxone sodium and its preparations according to claim 1, characterized in that, In step (3), the AQ column is Shiseido Capcell PAK C18 AQ.

5. The method for detecting impurities 2-aminothiazole and D-7-ACA lactone in ceftriaxone sodium and its preparations according to claim 1, characterized in that, In step (3), the mobile phase A is 0.005M ammonium formate-0.05% formic acid aqueous solution, the mobile phase B is acetonitrile, the injection volume is 20μl, the flow rate is 1.0ml / min, and the column temperature is 40℃.

6. The method for detecting impurities 2-aminothiazole and D-7-ACA lactone in ceftriaxone sodium and its preparations according to claim 1, characterized in that, In step (4), the mass spectrometry conditions are as follows: SIM mode, positive ion mode; SIM ions: 2-aminothiazole 101.0, D-7-ACA lactone 213.1; collision-induced dissociation: 2-aminothiazole 85~90, D-7-ACA lactone 90~100; split flow rate into the mass spectrometer detector: 0.1~0.2 ml / min; drying gas flow rate: 5~13 L / min; drying gas temperature: 320~350℃; nebulizer gas pressure: 1039~2599 Torr; capillary voltage: 1900~2100 V.

7. The method for detecting impurities 2-aminothiazole and D-7-ACA lactone in ceftriaxone sodium and its preparations according to claim 6, characterized in that, The mass spectrometry conditions were as follows: SIM mode, positive ion mode; SIM ions: 2-aminothiazole 101.0, D-7-ACA lactone 213.1; collision-induced dissociation: 2-aminothiazole 90, D-7-ACA lactone 95; drying gas flow rate: 12 L / min, drying gas temperature: 350 °C, nebulizer gas pressure: 1811 Torr, capillary voltage: 2000 V.

8. The method for detecting impurities 2-aminothiazole and D-7-ACA lactone in ceftriaxone sodium and its preparations according to claim 1, characterized in that, In step (5), the contents of impurities 2-aminothiazole and D-7-ACA lactone are calculated by peak area using the external standard method. The calculation formula is as follows: In the formula: W S W T Weigh the reference standard and test sample (mg) respectively; D S D T These are the dilution factors for the reference standard and the test sample, respectively; A S A T These represent the peak areas of the reference standard and the test sample, respectively; P represents the purity of the reference standard.

9. The application of the method for detecting impurities 2-aminothiazole and D-7-ACA lactone in ceftriaxone sodium and its preparations as described in any one of claims 1 to 8 in the quality control of ceftriaxone sodium and its preparations.

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