Detection method of related substances Ⅰ in piperacillin sodium and tazobactam sodium for injection

Abstract

The present invention provides a method for detecting related substances I in piperacillin sodium and tazobactam sodium for injection, belonging to the technical field of drug detection. The detection method comprises preparing a test solution and a reference solution by using piperacillin sodium and tazobactam sodium for injection and a piperacillin reference substance respectively, and then performing high performance liquid chromatography detection. The present invention fully takes into account the requirement of completely separating 11 impurities in piperacillin sodium and tazobactam sodium for injection by adjusting process parameters such as mobile phase and elution procedure, and successfully establishes a method for calculating the content of each impurity, so as to better control the quality of piperacillin sodium and tazobactam sodium for injection.

Description

Technical Field

[0001] The invention relates to drug detection technology, in particular to a method for detecting related substance I in piperacillin sodium and tazobactam sodium for injection. Background Art

[0002] The relationship between drug impurities and drug safety is a complex one affected by many factors. Usually, most impurities in drugs have potential biological activity, and some even interact with drugs, thus affecting the efficacy and safety of the drugs, and in severe cases may produce toxic effects.

[0003] Piperacillin sodium is a semi-synthetic penicillin antibiotic with a broad-spectrum antibacterial effect. Tazobactam sodium is a derivative of sulbactam sodium, a type II to V β-lactamase inhibitor with strong enzyme inhibitory activity, and can effectively inhibit various plasmid-mediated β-lactamases. Piperacillin sodium and tazobactam sodium for injection are widely used to treat infections caused by Staphylococcus, Escherichia coli, Citrobacter, Klebsiella, Enterobacter and Providence, sepsis caused by Pseudomonas aeruginosa, complicated cystitis, and pyelonephritis.

[0004] The detection of impurities and their contents in piperacillin sodium and tazobactam sodium for injection can effectively strengthen the quality control of piperacillin sodium and tazobactam sodium for injection. In existing studies, it was found that only the related substance Ⅰ in piperacillin sodium and tazobactam sodium for injection contained more than a dozen impurities, among which piperacillin impurity E, tazobactam impurity A, piperacillin impurity A, piperacillin impurity L, piperacillin impurity B1, piperacillin impurity M, piperacillin impurity B2, piperacillin impurity C1, piperacillin impurity C2, piperacillin impurity T, and piperacillin impurity D are all known impurities, and their corresponding structural formulas are as follows:

[0005] Impurity E of piperacillin is:

[0006]

[0007] Tazobactam impurity A is:

[0008]

[0009] Piperacillin impurity A (ampicillin) is:

[0010]

[0011] Piperacillin impurity L (ampicillin hydantoin analogue) is:

[0012]

[0013] The general structural formula of piperacillin impurity B1 / B2 (piperacillin penicillin acid) is:

[0014]

[0015] Among them, piperacillin impurity B1 is (2S,4S)-2-{(1R)-carboxy[2-(4-ethyl-2,3-dioxapiperazine-1-carboxylic acid amide)-2-phenylacetamido]methyl}-5,5-dimethylthiazolidine-4-carboxylic acid,

[0016] Piperacillin impurity B2 is (2R,4S)-2-{(1R)-carboxy[2-(4-ethyl-2,3-dioxapiperazine-1-carboxamido)-2-phenylacetamido]methyl}-5,5-dimethylthiazolidine-4-carboxylic acid;

[0017] Piperacillin impurity M (piperacillin oxalamide) is:

[0018]

[0019] The impurity C isomer 1 (i.e. C1) and isomer 2 (i.e. C2) of piperacillin (penicillin thiazole acid) are:

[0020]

[0021] Wherein, piperacillin impurity C is (4S)-2-{[2-(4-ethyl-2,3-dioxapiperazine-1-carboxamido)-2-phenylacetamido]methyl}-5,5-dimethylthiazolidine-4-carboxylic acid;

[0022] Piperacillin impurity T (piperacillin dimer) is:

[0023]

[0024] Piperacillin impurity D (piperacillin-based ampicillin) is:

[0025]

[0026] In the prior art, although it is known that the above-mentioned impurities may exist in piperacillin sodium and tazobactam sodium for injection, the prior art cannot separate and detect these impurities through a one-time detection, and can only control the total impurities through detection, which makes it difficult to better control the quality of piperacillin sodium and tazobactam sodium for injection and ensure drug safety. Summary of the invention

[0027] In view of the above problems, the present invention provides a method for detecting related substance I in piperacillin sodium and tazobactam sodium for injection.

[0028] To achieve the above purpose, the technical solution adopted by the present invention is:

[0029] A method for detecting related substance I in piperacillin sodium and tazobactam sodium for injection, characterized in that the detection method comprises the following steps:

[0030] Prepare the test solution with piperacillin sodium and tazobactam sodium for injection;

[0031] Take piperacillin reference substance to prepare reference substance solution;

[0032] Take the test solution and the reference solution respectively, use a solution obtained by mixing methanol, 10% tetrabutylammonium hydroxide solution, 27.6 g / L sodium dihydrogen phosphate dihydrate solution and water in a volume ratio of 285:3:100:612 as mobile phase A, and use a solution obtained by mixing methanol, 10% tetrabutylammonium hydroxide solution, 27.6 g / L sodium dihydrogen phosphate dihydrate solution and water in a volume ratio of 615:3:100:282 as mobile phase B, and perform high performance liquid chromatography detection to obtain the corresponding chromatographic peaks for separating the impurities in the related substance I;

[0033] Among them, related substance Ⅰ includes piperacillin impurity E, tazobactam impurity A, piperacillin impurity A, piperacillin impurity L, piperacillin impurity B1, piperacillin impurity M, piperacillin impurity B2, piperacillin impurity C1, piperacillin impurity C2, piperacillin impurity T and piperacillin impurity D.

[0034] Furthermore, the elution mode of the high performance liquid chromatography detection is gradient elution;

[0035] The conditions of the gradient elution are:

[0036] 0-6 min, 100% mobile phase A, 0% mobile phase B;

[0037] 6-55 min, 100% → 71% mobile phase A, 0% → 29% mobile phase B;

[0038] 55-73 min, 71% → 10% mobile phase A, 29% → 90% mobile phase B;

[0039] 73-85 min, 10% mobile phase A, 90% mobile phase B;

[0040] 85-86 min, 10% → 100% mobile phase A, 90% → 0% mobile phase B;

[0041] 86-105min, 100% mobile phase A, 0% mobile phase B.

[0042] Furthermore, the detection method can also use the external standard method to calculate the content of any impurity in the related substance I.

[0043] Furthermore, the method for calculating the content of any impurity in the related substance I is to calculate the peak area according to the main component external standard method with a correction factor, specifically:

[0044] The content of any impurity in the relevant substance I (%) = (A t-相应的杂质 / A s )×(C s / C t )×P×F 相应的杂质 ×100%;

[0045] In the formula, A t-相应杂质 is the peak area of ​​any impurity peak in the chromatogram obtained from the test solution;

[0046] A s is the peak area of ​​piperacillin peak in the chromatogram obtained from the reference solution;

[0047] C t is the concentration of piperacillin in the test solution;

[0048] C s is the concentration of piperacillin in the reference solution;

[0049] P is the content of piperacillin in the reference substance;

[0050] F 相应的杂质 is the correction factor of any impurity relative to piperacillin;

[0051] Among them, the correction factor of piperacillin impurity E is 0.42;

[0052] The correction factor for impurity A of tazobactam is 1.9;

[0053] The correction factor for piperacillin impurity A is 1.3;

[0054] The values ​​of piperacillin impurity L, piperacillin impurity B1, piperacillin impurity M, piperacillin impurity B2, piperacillin impurity C1, piperacillin impurity C2, piperacillin impurity T and piperacillin impurity D are all 1.0.

[0055] Furthermore, the limit of piperacillin impurity E in the piperacillin sodium and tazobactam sodium for injection is 0.5%, the limit of tazobactam impurity A is 1.0%, the limit of piperacillin impurity A is 0.3%, the limit of piperacillin impurity L is 0.3%, the total limit of piperacillin impurities B1 and B2 is 3.0%, the limit of piperacillin impurity M is 0.2%, the total limit of piperacillin impurities C1 and C2 is 1.0%, the limit of piperacillin impurity T is 0.5%, and the limit of piperacillin impurity D is 1.0%.

[0056] Furthermore, the mobile phase A needs to be adjusted to a pH value of 5.50±0.05 with phosphoric acid; and the mobile phase B needs to be adjusted to a pH value of 5.50±0.05 with phosphoric acid.

[0057] Furthermore, the concentration of piperacillin in the test solution is 5.0-5.3 mg / mL, and the concentration of tazobactam is 0.62-0.66 mg / mL.

[0058] Furthermore, the concentration of piperacillin in the reference solution is 0.05-0.10 mg / mL.

[0059] Furthermore, the solvent for preparing the reference solution is mobile phase B.

[0060] Furthermore, the chromatographic conditions of the HPLC detection also include: column temperature of 40-45°C, detection wavelength of 220nm, injection volume of 10μL, and flow rate of 0.8-1.2mL / min.

[0061] The beneficial effects of the method for detecting related substance I in piperacillin sodium and tazobactam sodium for injection of the present invention are:

[0062] The present invention establishes a method for detecting related substances I in piperacillin sodium and tazobactam sodium for injection by high performance liquid chromatography, and can successfully separate and detect the contents of 11 impurities including piperacillin impurity E, tazobactam impurity A, piperacillin impurity A, piperacillin impurity L, piperacillin impurity B1, piperacillin impurity M, piperacillin impurity B2, piperacillin impurity C1, piperacillin impurity C2, piperacillin impurity T and piperacillin impurity D, thereby realizing the detection and control of multiple impurities in piperacillin sodium and tazobactam sodium for injection;

[0063] The detection method of the present invention fully takes into account the requirement of completely separating 11 impurities in piperacillin sodium and tazobactam sodium for injection by adjusting process parameters such as mobile phase and elution program, and successfully establishes a method for calculating the content of each impurity, so as to better control the quality of piperacillin sodium and tazobactam sodium for injection;

[0064] The detection method of the present invention can quickly, simply, accurately and reliably obtain the quality of piperacillin sodium and tazobactam sodium for injection, solves the problem that multiple impurities cannot be detected at one time in the prior art, and further realizes comprehensive control of the quality of piperacillin sodium and tazobactam sodium for injection, and provides a new reference standard for the quality control of piperacillin sodium and tazobactam sodium for injection. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 is a chromatogram of the test solution in Example 1 of the present invention;

[0066] Figure 2is a chromatogram of the system suitability solution in Experimental Example 1 of the present invention;

[0067] Figure 3 It is the chromatogram of the sensitivity solution in Experimental Example 1 of the present invention. DETAILED DESCRIPTION

[0068] The technical solutions in the embodiments of the present invention are described clearly and completely below. In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention can also be implemented in other ways different from those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0069] Example 1 A method for detecting related substance I in piperacillin sodium and tazobactam sodium for injection

[0070] This embodiment is a method for detecting related substance I in piperacillin sodium and tazobactam sodium for injection, comprising the following specific steps:

[0071] 1) Preparation of test solution and reference solution

[0072] 11) Preparation of test solution

[0073] Take an appropriate amount of piperacillin sodium and tazobactam sodium for injection, weigh accurately, dissolve in water and quantitatively dilute to prepare a test solution containing 5.1 mg of piperacillin and 0.64 mg of tazobactam per 1 mL. The concentration of piperacillin in the test solution is C t =5.1mg / mL.

[0074] 12) Preparation of reference solution

[0075] Methanol, 10% tetrabutylammonium hydroxide solution, 27.6 g / L sodium dihydrogen phosphate dihydrate solution and water were mixed in a volume ratio of 615:3:100:282, and the pH value was adjusted to 5.50±0.05 (the pH value after adjustment in this embodiment was 5.50) with phosphoric acid to prepare mobile phase B for use;

[0076] Take an appropriate amount of piperacillin reference substance (the content of piperacillin in the piperacillin reference substance in this embodiment is P=96.1%), accurately weigh it, add mobile phase B to dissolve it and quantitatively dilute it to prepare a reference substance solution containing about 0.06 mg of piperacillin per 1 mL, wherein the concentration of piperacillin in the reference substance solution is C s =0.06mg / mL.

[0077] 2) High performance liquid chromatography detection

[0078] 21) Methanol, 10% tetrabutylammonium hydroxide solution, 27.6 g / L sodium dihydrogen phosphate dihydrate solution and water were mixed in a volume ratio of 285:3:100:612, and the pH value was adjusted to 5.50±0.05 (the pH value after adjustment in this embodiment was 5.50) with phosphoric acid to prepare mobile phase A for use;

[0079] Take the reference solution and perform high performance liquid chromatography to obtain a chromatogram of the reference solution, in which the peak area A of piperacillin sodium s .

[0080] Among them, the HPLC conditions for detecting the reference solution are:

[0081] Chromatographic column: Octadecylsilane bonded silica gel (Waters XTerra MS C18 column, 4.6 mm × 250 mm, 5 μm or a chromatographic column with equivalent performance) is used as filler;

[0082] Mobile phase: the above mobile phase A and the above mobile phase B;

[0083] The elution method is gradient elution; elution program:

[0084] 0-6 min, 100% mobile phase A, 0% mobile phase B;

[0085] 6-55 min, 100% → 71% mobile phase A, 0% → 29% mobile phase B;

[0086] 55-73 min, 71% → 10% mobile phase A, 29% → 90% mobile phase B;

[0087] 73-85 min, 10% mobile phase A, 90% mobile phase B;

[0088] 85-86 min, 10% → 100% mobile phase A, 90% → 0% mobile phase B;

[0089] 86-105 min, 100% mobile phase A, 0% mobile phase B;

[0090] Flow rate: 1.0 mL / min;

[0091] Column temperature: 42°C;

[0092] Detection wavelength: 220nm;

[0093] Injection volume: 10 μL.

[0094] 22) Take the test solution and perform HPLC under the above chromatographic conditions. The chromatogram of the test solution is shown in Figure 1 According to the chromatogram, the peak area A of the corresponding impurity contained in the test solution is obtained. t-相应的杂质; That is, the peak areas corresponding to piperacillin impurity E, tazobactam impurity A, piperacillin impurity A, piperacillin impurity L, piperacillin impurity B1, piperacillin impurity M, piperacillin impurity B2, piperacillin impurity C1, piperacillin impurity C2, piperacillin impurity T and piperacillin impurity D contained in the test solution are obtained respectively, that is, A t-哌拉西林杂质E , A t-他唑巴坦杂质A , A t-哌拉西林杂质A , A t-哌拉西林杂质L , A t-哌拉西林杂质B1 , A t-哌拉西林杂质M , A t-哌拉西林杂质B2 , A t-哌拉西林杂质C1 , A t-哌拉西林杂质C2 , A t-哌拉西林杂质T , A t-哌拉西林杂质D .

[0095] 23) If there are impurity peaks in the chromatogram of the test solution, calculate the peak area using the main component external standard method with correction factors, specifically:

[0096] The content of any impurity in the relevant substance I (%) = (A t-相应的杂质 / A s )×(C s / C t )×P×F 相应的杂质 ×100%;

[0097] In the formula, A t-相应的杂质 is the peak area of ​​any impurity peak in the chromatogram obtained from the test solution;

[0098] A s is the peak area of ​​piperacillin peak in the chromatogram obtained from the reference solution;

[0099] C t is the concentration of piperacillin in the test solution;

[0100] C s is the concentration of piperacillin in the reference solution;

[0101] P is the content of piperacillin in the piperacillin reference substance;

[0102] F 相应的杂质 is the correction factor of any impurity relative to piperacillin;

[0103] The limits of each impurity and the corresponding correction factors are shown in the following table:

[0104] Table 1 List of impurity limits and correction factors

[0105]

[0106] In this embodiment, the content of piperacillin impurity E in the related substance I of piperacillin sodium and tazobactam sodium for injection is 0.09%, the content of tazobactam impurity A is 0.04%, the content of piperacillin impurity A is 0.07%, the content of piperacillin impurity L is 0.11%, the total content of piperacillin impurities B1 and B2 is 0.20%, the content of piperacillin impurity M is 0.03%, the total content of piperacillin impurities C1 and C2 is 0.01%, the content of piperacillin impurity T is 0.10% and the content of piperacillin impurity D is 0.12%.

[0107] Examples 2 to 5 Detection Method for Related Substance I in Piperacillin Sodium and Tazobactam Sodium for Injection

[0108] Examples 2 to 5 are respectively a method for detecting related substance I in piperacillin sodium and tazobactam sodium for injection, and their steps are basically the same as those in Example 1, and the only difference is the different process parameters, as shown in Table 2 for details:

[0109] Table 2 List of process parameters in Examples 2 to 5

[0110]

[0111] The process parameters and steps of other parts of Examples 2 to 5 are the same as those of Example 1.

[0112] Experimental Example 1 Methodological Investigation

[0113] In this experimental example, the detection method of related substance Ⅰ in piperacillin sodium and tazobactam sodium for injection was investigated, mainly focusing on the system applicability, sensitivity, accuracy, precision, detection limit and quantification limit, and durability of the content determination method.

[0114] 1. System Applicability

[0115] Take appropriate amounts of tazobactam impurity A reference substance, tazobactam reference substance and piperacillin peak identification reference substance (purchased EP), add mobile phase B to dissolve and quantitatively dilute to prepare a system suitability solution containing approximately 0.1 mg of tazobactam impurity A, 0.76 mg of tazobactam, and 6 mg of piperacillin peak identification reference substance per 1 mL.

[0116] The chromatographic conditions of Example 1 were used to perform HPLC detection, and the chromatogram of the obtained system suitability solution was shown in Figure 2As can be seen from the figure, the peak order is piperacillin impurity E, tazobactam impurity A, tazobactam, piperacillin impurity A, piperacillin impurity L, piperacillin impurity B1, piperacillin impurity M, piperacillin impurity B2, piperacillin impurity C1, piperacillin impurity C2, piperacillin, piperacillin impurity T, piperacillin impurity D. The resolution between the main peak and the adjacent known impurities, the piperacillin impurity E peak and the tazobactam impurity A peak should be no less than 1.5; the resolution between other known impurity peaks should be no less than 1.0; the tailing factor of piperacillin in the control solution should be no more than 2.0.

[0117] 2. Sensitivity

[0118] Accurately measure an appropriate amount of the reference solution prepared in Example 1, and quantitatively dilute it with mobile phase B to make a solution containing approximately 2.4 μg of piperacillin sodium per 1 mL to obtain a sensitivity solution.

[0119] The chromatographic conditions of Example 1 were used to perform HPLC detection, and the chromatogram of the obtained sensitive solution was shown in FIG. Figure 3 , where the signal-to-noise ratio of piperacillin sodium is 406 (should be greater than 10).

[0120] 3. Accuracy

[0121] Accurately measure an appropriate amount of the test solution prepared in Example 1, and add three mixed impurity reference solutions containing 50%, 100% and 150% of the known impurity limits, respectively. Prepare 3 portions of each concentration in parallel, for a total of 9 portions, to obtain 9 portions of accuracy solution. Take the above 9 portions of accuracy solution, perform HPLC detection using the chromatographic conditions of Example 1, and calculate the amount and recovery rate of each impurity in the test sample.

[0122] Among them, recovery rate (%) = (measured amount - original amount of each impurity in the test sample) / added amount × 100%;

[0123] The recovery rate experimental results obtained are: recovery rate of piperacillin impurity E: 101.8%, recovery rate of tazobactam impurity A: 99.4%, recovery rate of piperacillin impurity A: 98.7%, recovery rate of piperacillin impurity L: 100.1%, recovery rate of piperacillin impurity B1 / B2: 103.2%, recovery rate of piperacillin impurity M: 99.3%, recovery rate of piperacillin impurity C (C1 / C2): 105.6%, recovery rate of piperacillin impurity T: 99.5%, and recovery rate of piperacillin impurity D: 98.2%.

[0124] The accuracy recovery rate standard is: if in a 100% recovery solution, when 1% ≤ impurity content < 10%, the recovery rate of the impurity content should be within the range of 92% to 105%; when 0.1% ≤ impurity content < 1%, the recovery rate of the impurity content should be within the range of 90% to 108%.

[0125] It can be seen that the recovery rates of each impurity content in the present invention are all within the accuracy recovery rate standard range.

[0126] 4. Precision

[0127] Accurately measure an appropriate amount of the test solution prepared in Example 1, add mixed impurity reference solutions containing known impurity concentrations, prepare 6 portions in parallel, and obtain 6 precision solutions. Take the above 6 precision solutions, perform HPLC detection using the chromatographic conditions of Example 1, and calculate the amount and RSD of each impurity in the test sample.

[0128] The obtained RSD results are: RSD of piperacillin impurity E: 1.3%, RSD of tazobactam impurity A: 1.5%, RSD of piperacillin impurity A: 1.1%, RSD of piperacillin impurity L: 0.9%, RSD of piperacillin impurity B1 / B2: 1.9%, RSD of piperacillin impurity M: 3.4%, RSD of piperacillin impurity C (C1 / C2): 2.9%, RSD of piperacillin impurity T: 1.2%, RSD of piperacillin impurity D: 1.2%.

[0129] Precision RSD standard: The RSD of each impurity content in 6 precision solutions should not be greater than 5%.

[0130] It can be seen that the RSD of each impurity in the present invention is within the precision RSD standard range.

[0131] Obviously, the described embodiments are only some embodiments of the present invention, not all 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.

Claims

1. A method for detecting related substance I in piperacillin sodium and tazobactam sodium for injection, characterized in that: The detection method comprises the following steps: Prepare the test solution with piperacillin sodium and tazobactam sodium for injection; Take piperacillin reference substance to prepare reference substance solution; Take the test solution and the reference solution respectively, use a solution obtained by mixing methanol, 10% tetrabutylammonium hydroxide solution, 27.6 g / L sodium dihydrogen phosphate dihydrate solution and water in a volume ratio of 285:3:100:612 as mobile phase A, and use a solution obtained by mixing methanol, 10% tetrabutylammonium hydroxide solution, 27.6 g / L sodium dihydrogen phosphate dihydrate solution and water in a volume ratio of 615:3:100:282 as mobile phase B, and perform high performance liquid chromatography detection to obtain the corresponding chromatographic peaks for separating the impurities in the related substance I; Among them, related substances Ⅰ include piperacillin impurity E, tazobactam impurity A, piperacillin impurity A, piperacillin impurity L, piperacillin impurity B1, piperacillin impurity M, piperacillin impurity B2, piperacillin impurity C1, piperacillin impurity C2, piperacillin impurity T and piperacillin impurity D; Impurity E of piperacillin is: Tazobactam impurity A is: Piperacillin impurity A is: The impurity L of piperacillin is: The general structural formula of piperacillin impurity B1 / B2 is: Among them, piperacillin impurity B1 is (2S,4S)-2-{(1R)-carboxy[2-(4-ethyl-2,3-dioxapiperazine-1-carboxylic acid amide)-2-phenylacetamido]methyl}-5,5-dimethylthiazolidine-4-carboxylic acid, Piperacillin impurity B2 is (2R,4S)-2-{(1R)-carboxy[2-(4-ethyl-2,3-dioxapiperazine-1-carboxamido)-2-phenylacetamido]methyl}-5,5-dimethylthiazolidine-4-carboxylic acid; Piperacillin impurity M is: Piperacillin impurity C1 is isomer 1, and piperacillin impurity C2 is isomer 2, specifically: The impurity T of piperacillin is: Piperacillin impurity D is: The elution mode of the high performance liquid chromatography detection is gradient elution; The conditions of the gradient elution are: 0-6 min, 100% mobile phase A, 0% mobile phase B; 6-55 min, 100% → 71% mobile phase A, 0% → 29% mobile phase B; 55-73 min, 71% → 10% mobile phase A, 29% → 90% mobile phase B; 73-85 min, 10% mobile phase A, 90% mobile phase B; 85-86 min, 10% → 100% mobile phase A, 90% → 0% mobile phase B; 86-105 min, 100% mobile phase A, 0% mobile phase B; The chromatographic column is octadecylsilane bonded silica gel; The mobile phase A also needs to be adjusted to a pH value of 5.50±0.05 with phosphoric acid; the mobile phase B also needs to be adjusted to a pH value of 5.50±0.05 with phosphoric acid.

2. The method for detecting related substance I in piperacillin sodium and tazobactam sodium for injection according to claim 1, characterized in that: The detection method can also use the external standard method to calculate the content of any impurity in the related substance I.

3. The method for detecting related substance I in piperacillin sodium and tazobactam sodium for injection according to claim 2, characterized in that: The method for calculating the content of any impurity in the related substance I is to calculate the peak area using the main component external standard method with a correction factor, specifically: The content of any impurity in the relevant substance Ⅰ / % = A t-相应的杂质 / A s ×C s / C t ×P×F 相应的杂质 ×100%; where A t-相应杂质 is the peak area of ​​any impurity peak in the chromatogram obtained from the test solution; A s is the peak area of ​​piperacillin peak in the chromatogram obtained from the reference solution; C t is the concentration of piperacillin in the test solution; C s is the concentration of piperacillin in the reference solution; P is the content of piperacillin in the piperacillin sodium reference substance; F 相应的杂质 is the correction factor of any impurity relative to piperacillin; Among them, the correction factor of piperacillin impurity E is 0.42; The correction factor for impurity A of tazobactam is 1.9; The correction factor for piperacillin impurity A is 1.3; The values ​​of piperacillin impurity L, piperacillin impurity B1, piperacillin impurity M, piperacillin impurity B2, piperacillin impurity C1, piperacillin impurity C2, piperacillin impurity T and piperacillin impurity D are all 1.

0.

4. The method for detecting related substance I in piperacillin sodium and tazobactam sodium for injection according to claim 3, characterized in that: The limit of piperacillin impurity E in the piperacillin sodium and tazobactam sodium for injection is 0.5%, the limit of tazobactam impurity A is 1.0%, the limit of piperacillin impurity A is 0.3%, the limit of piperacillin impurity L is 0.3%, the total limit of piperacillin impurities B1 and B2 is 3.0%, the limit of piperacillin impurity M is 0.2%, the total limit of piperacillin impurities C1 and C2 is 1.0%, the limit of piperacillin impurity T is 0.5%, and the limit of piperacillin impurity D is 1.0%.

5. The method for detecting related substance I in piperacillin sodium and tazobactam sodium for injection according to claim 1, 3 or 4, characterized in that: The concentration of piperacillin in the test solution is 5.0-5.3 mg / mL, and the concentration of tazobactam is 0.62-0.66 mg / mL.

6. The method for detecting related substance I in piperacillin sodium and tazobactam sodium for injection according to claim 1, 3 or 4, characterized in that: The concentration of piperacillin in the reference solution is 0.05-0.10 mg / mL.

7. The method for detecting related substance I in piperacillin sodium and tazobactam sodium for injection according to claim 1, 3 or 4, characterized in that: The solvent for preparing the reference solution is mobile phase B.

8. The method for detecting related substance I in piperacillin sodium and tazobactam sodium for injection according to claim 1, 3 or 4, characterized in that: The chromatographic conditions of the high performance liquid chromatography detection also include: column temperature of 40-45° C., detection wavelength of 220 nm, injection volume of 10 μL, and flow rate of 0.8-1.2 mL / min.

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