Method for detecting residual solvent in cefazolin sodium and application

Abstract

The invention discloses a method for detecting a residual solvent in cefazolin sodium, which comprises the following steps of: performing gas chromatography detection by adopting a headspace sampling mode, recording a chromatogram, and performing quantitative analysis on the chromatogram by adopting an external standard method. Wherein the chromatographic column is a capillary column taking polyethylene glycol (or similar polarity) as a stationary phase or a gas-phase capillary chromatographic column with equivalent efficiency; in the heating procedure, the initial temperature ranges from 30 DEG C to 40 DEG C and is maintained for 5 minutes, and the temperature is increased to 200 DEG C at the speed of 10 DEG C per minute and maintained for 2 minutes; the sample size is 1 microliter. The detection method provided by the invention has good specificity and system adaptability, good sample injection precision, extremely low detection limit and quantitation limit, good durability, good linearity, good accuracy and very high sensitivity, and can be widely applied to quality control of the cefazolin sodium product.

Description

Technical Field

[0001] The invention belongs to the technical field of drug analysis, and particularly relates to a detection method and application of residual solvent in cefazolin sodium. Background Art

[0002] The chemical name of cefazolin sodium is (6R,7R)-3-[[(5-methyl-1,3,4-thiadiazol-2-yl)thio]methyl]-7-[(1H-tetrazol-1-yl)acetylamino]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid sodium salt. It is a first-generation cephalosporin with a broad antibacterial spectrum and is used to treat a variety of bacterial infections. The clinical indications for listing are: 1. It is suitable for the treatment of respiratory tract infections such as otitis media, bronchitis, pneumonia, urinary tract infections, skin and soft tissue infections, bone and joint infections, sepsis, infective endocarditis, hepatobiliary system infections, and eye, ear, nose, and throat infections caused by sensitive bacteria. 2. This product can also be used as a preventive drug before surgery. 3. This product should not be used for central nervous system infections. The efficacy is poor for chronic urinary tract infections, especially those with urinary tract anatomical abnormalities. This product should not be used to treat gonorrhea and syphilis.

[0003] Organic solvents such as acetone, methanol, dichloromethane, acetonitrile, N,N-dimethylformamide, N,N-dimethylaniline, etc. are used in the production of cefazolin sodium raw materials. Since residual solvents are impurities in drugs that are harmful to the human body, their content should be controlled within a limit during the production process.

[0004] At present, the United States Pharmacopoeia and the Chinese Pharmacopoeia (2020 edition) only include the quality standards of cefazolin sodium, but neither includes the detection methods and standards for residual solvents in cefazolin sodium. In order to more comprehensively detect the content of residual solvents in cefazolin sodium, it is necessary to establish a detection method for residual solvents of acetone, methanol, dichloromethane, acetonitrile, and N,N-dimethylformamide in cefazolin sodium. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the defect of the lack of a detection method for residual solvents in cefazolin sodium in the prior art, and to provide a detection method and application of residual solvents in cefazolin sodium. The detection method of the present invention can realize the detection of residual solvents in cefazolin sodium. Methodological verification shows that the detection method of the present invention has good specificity and system adaptability, good injection precision, extremely low detection limit and quantitative limit, good durability, good linearity and good accuracy, and the method has high sensitivity, and can be widely used in the quality control of cefazolin sodium products.

[0006] The present invention provides a method for detecting residual solvents in cefazolin sodium, which is characterized in that it adopts gas chromatography detection in a headspace injection mode, records the chromatogram, and adopts an external standard method to perform quantitative analysis on the spectrum;

[0007] Among them, the detection conditions of the chromatography are:

[0008] Instrument: Gas chromatograph;

[0009] Chromatographic column: a capillary column with polyethylene glycol (or similar polarity) as the stationary phase or a gas phase capillary column with equivalent performance;

[0010] Detector: hydrogen flame ionization detector (FID); carrier gas: nitrogen;

[0011] Inlet temperature: 200°C; Detector temperature: 250°C;

[0012] Heating program: the starting temperature is in the range of 30℃~40℃, maintained for 5 minutes, and then increased to 200℃ at a rate of 10℃ per minute, and maintained for 2 minutes;

[0013] Injection volume: 1μl.

[0014] (1) Solution preparation: (a) Solvent: dimethyl sulfoxide; (b) Test solution: take about 1.0 g of the product, accurately weigh it, put it in a 10 ml volumetric flask, add solvent to dissolve and dilute to the scale, shake well, and use it as the test solution; (c) Reference solution: accurately weigh appropriate amounts of methanol, acetonitrile, acetone, dichloromethane, and N,N-dimethylformamide, add solvent to dissolve and dilute to make a mixed solution containing about 300 μg of methanol, 41 μg of acetonitrile, 500 μg of acetone, 60 μg of dichloromethane, and 88 μg of N,N-dimethylformamide per 1 ml, and use it as the reference solution;

[0015] (2) Determination method: Take 1 μl of the reference solution and inject it into the gas chromatograph. Record the chromatogram. The order of peaks is acetone, methanol, dichloromethane, acetonitrile, and N,N-dimethylformamide. The separation between the peaks should meet the requirements.

[0016] The contents of residual solvents such as acetone, methanol, dichloromethane, acetonitrile and N,N-dimethylformamide were calculated by peak area according to the external standard method.

[0017] Calculated by peak area using the external standard method, the methanol content should not exceed 0.3%, the acetone content should not exceed 0.5%, the acetonitrile content should not exceed 0.041%, the dichloromethane content should not exceed 0.06%, and the N,N-dimethylformamide content should not exceed 0.088%.

[0018] The calculation formula of external standard method is:

[0019]

[0020] Where: As is the peak area of ​​the corresponding residual solvent in the test solution;

[0021] Wr is the weight of the reference substance, mg;

[0022] Ar is the peak area of ​​the corresponding reference solvent in the reference solution;

[0023] Ws is the weight of the test sample, mg;

[0024] Sr is the dilution multiple of the reference solution;

[0025] Ss is the dilution factor of the test solution.

[0026] In a certain embodiment of the present invention, the specification of the chromatographic column is preferably DB-WAX, 30m×0.32mm×1.0μm, or a gas capillary chromatographic column with equivalent performance.

[0027] In a certain embodiment of the present invention, the column flow rate varies in the range of 1.8 ml / min to 2.2 ml / min, preferably 2 ml / min.

[0028] In a certain embodiment of the present invention, the split ratio is 5:1.

[0029] In a certain embodiment of the present invention, the temperature of the starting column varies in the range of 30°C to 40°C, preferably 35°C.

[0030] In a certain embodiment of the present invention, the detector is a hydrogen flame ionization detector.

[0031] The detection method of the present invention, the results of the method verification show that:

[0032] (1) Specificity: The blank solvent does not interfere with the residual solvent determination; the resolution of each peak is greater than 1.5; this method has good specificity.

[0033] (2) Durability: When the column flow rate was changed from 1.8 ml / min to 2.2 ml / min and the initial column temperature was 30°C and 40°C, the blank solvent did not interfere with the determination. In the reference solution, the resolution of each peak was greater than 1.5. According to the external standard method, the number of residual solvents detected in the test solution was consistent, and the range of the residual solvent content was less than 0.02%, indicating that the column flow rate was between 1.8 ml / min and 2.2 ml / min. When the initial column temperature was between 30°C and 40°C, the method had good durability.

[0034] (3) Linearity and range: Acetone: y = 1,517,540x-10,918,390, r = 0.9999, range: 51.320 μg / ml to 769.800 μg / ml, ratio: 1.43; Methanol: y = 977998x + 386382, r = 0.9998, range: 32.340 μg / ml to 485.100 μg / ml, ratio: 0.12; Dichloromethane: y = 400,351x + 2,471,419, r = 0.9968, range: 6.290 μg / ml to 94.350 μg / ml, ratio: 9 .11; acetonitrile: y=1,593,381x+2,290,489, r=0.9997, range: 4.440μg / ml~66.600μg / ml, ratio: 3.12; N,N-dimethylformamide: y=838,234x+1,310,689, r=0.9998, range: 11.270μg / ml~169.050μg / ml, ratio: 1.36; Conclusion: The correlation coefficient r of each solvent is greater than 0.990, and the ratio is less than 25%. The linear relationship of each solvent is good within the range of 10% to 150% of the concentration limit of the test solution.

[0035] (4) Quantification limit and detection limit: Acetone quantification limit: 2.005 ng, equivalent to 0.0020% of the test solution concentration; methanol quantification limit: 1.992 ng, equivalent to 0.0020% of the test solution concentration; dichloromethane quantification limit: 3.050 ng, equivalent to 0.0031% of the test solution concentration; acetonitrile quantification limit: 0.623 ng, equivalent to 0.0006% of the test solution concentration; N,N-dimethylformamide quantification limit: 1.824 ng, equivalent to 0.0018% of the test solution concentration. The detection limit of acetone is 0.827ng, which is equivalent to 0.0008% of the concentration of the test solution; the detection limit of methanol is 0.560ng, which is equivalent to 0.0006% of the concentration of the test solution; the detection limit of dichloromethane is 0.915ng, which is equivalent to 0.0009% of the concentration of the test solution; the detection limit of acetonitrile is 0.208ng, which is equivalent to 0.0002% of the concentration of the test solution; the detection limit of N,N-dimethylformamide is 1.368ng, which is equivalent to 0.0014% of the concentration of the test solution. The detection limit of each solvent is between 0.208ng and 1.368ng, which is equivalent to 0.0002% to 0.0014% of the concentration of the test solution, and can be effectively detected. The detection limit concentration of each solvent is less than 1 / 5 of the limit concentration; the quantitative limit of each solvent is between 0.623ng and 1.824ng, which is equivalent to 0.0006% to 0.0031% of the test sample concentration and can be effectively quantified. The quantitative limit concentration of each solvent is less than 1 / 2 of the limit concentration.

[0036] (5) Accuracy: The recoveries of three different concentrations, high (120%), medium (100%), and low (80%), were all within the range of 80% to 120%. According to the external standard method, the recoveries of each solvent were within the range of 92.55% to 116.13%; the RSDs were all less than 10.0% (n=9). This method has good accuracy.

[0037] (6) Precision: 1) Injection precision: After 6 consecutive measurements, the RSD of the peak area of ​​each solvent was less than 10.0%; 2) Repeatability: The RSD of the detected amount of each solvent was less than 10.0%; 3) Intermediate precision: The RSD of the detected amount of each solvent was less than 10.0%. The results show that this method has good precision.

[0038] The present invention also provides an application of the above-mentioned method for detecting the residual solvent in cefazolin sodium to detecting the residual solvent content in a cefazolin sodium raw material or preparation.

[0039] In the present invention, the term "external standard method" refers to a method of using a pure product of the component to be measured as a reference substance and comparing the response signals of the reference substance and the component to be measured in the sample for quantitative analysis.

[0040] Without violating the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0041] The reagents and raw materials used in the present invention are commercially available.

[0042] The positive and progressive effects of the present invention are:

[0043] (1) The method of the present invention can simply, quickly and accurately detect the residual amounts of acetone, methanol, dichloromethane, acetonitrile and N,N-dimethylformamide in cefazolin sodium. The method has good separation of each solvent, suitable peak elution time and good peak shape.

[0044] (2) The present invention has good specificity, and the blank solvent does not interfere with the residual solvent determination; the separation degree of each peak is greater than 1.5.

[0045] (3) The method described in the present invention is highly sensitive and has extremely low detection limits and quantification limits. The detection limits of each solvent are between 0.208ng and 1.368ng, which is equivalent to 0.0002% to 0.0014% of the test sample concentration and can be effectively detected. The detection limit concentration of each solvent is less than 1 / 5 of the limit concentration; the quantification limit of each solvent is between 0.623ng and 1.824ng, which is equivalent to 0.0006% to 0.0031% of the test sample concentration and can be effectively quantified.

[0046] (4) The method described in the present invention has good linearity, good precision and durability.

[0047] (5) The method described in the present invention has good accuracy. The recovery rates of three different concentrations, high (120%), medium (100%), and low (80%), are all in the range of 80% to 120%. Calculated by the external standard method: the recovery rate of each solvent is in the range of 92.55% to 116.13%; the RSDs are all less than 10.0% (n=9). BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is the GC spectrum of the triethylamine-fixed solution used in the exploration of chromatographic conditions for determining residual solvent in Example 1 (with severe tailing).

[0049] Figure 2 This is the GC spectrum of the test solution in the method verification-specificity for solvent residue in Example 2.

[0050] Figure 3 This is the GC spectrum of the mixed solution in the method verification-specificity for solvent residue in Example 2.

[0051] Figure 4 This is the linear correlation diagram of acetone in Example 4.

[0052] Figure 5 This is the linear correlation diagram of methanol in Example 4.

[0053] Figure 6 This is the linear correlation diagram of dichloromethane in Example 4.

[0054] Figure 7 It is the linear correlation diagram of acetonitrile in Example 4.

[0055] Figure 8 This is the linear correlation diagram of N,N-dimethylformamide in Example 4.

[0056] Fig. 9 This is the GC spectrum of the 120% high concentration solution in the method verification-accuracy for residual solvent in Example 7.

[0057] Fig.10 This is the GC spectrum of the reference solution in the method verification-intermediate precision for solvent residue in Example 8.

[0058] Fig.11 This is the GC spectrum of the test solution in the method verification-intermediate precision for solvent residue in Example 8. DETAILED DESCRIPTION

[0059] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. The experimental methods in the following examples without specifying specific conditions are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0060] Sample: Cefazolin sodium (manufacturer: North China Pharmaceutical; batch number: K2501905022). Methanol (grade: HPLC, source manufacturer: MREDA), acetonitrile (grade: HPLC, source manufacturer: MREDA), dichloromethane (grade: HPLC, source manufacturer: MREDA), acetone (grade: HPLC, source manufacturer: Beijing Chemical Reagent), N,N-dimethylformamide (grade: HPLC, source manufacturer: MREDA), dimethyl sulfoxide (grade: HPLC, source manufacturer: MREDA). The remaining reagents in the present invention are all analytically pure.

[0061] Instruments: gas chromatograph (model Trace1300, manufacturer: Thermo), electronic balance (model XS105DU, manufacturer: Mettler-Toledo Instrument Co., Ltd.), electronic balance (model CP214, manufacturer: OHVAS).

[0062] Example 1 Detection method development

[0063] Chromatographic conditions:

[0064] Chromatographic column: a capillary column with polyethylene glycol (or similar polarity) as the stationary phase (DB-WAX, 30m×0.32mm×1.0μm, or a chromatographic column with similar polarity);

[0065] Detector: FID; Carrier gas: nitrogen;

[0066] Inlet temperature: 200°C; Detector temperature: 250°C;

[0067] Heating program: starting temperature at 35°C, maintained for 5 minutes, then increased to 200°C at a rate of 10°C per minute, maintained for 2 minutes;

[0068] Flow rate: 2ml / min; split flow rate: 10ml / min;

[0069] Injection volume: 1μl; Hydrogen: 40ml / min;

[0070] Air: 40ml / min; Nitrogen: 40ml / min;

[0071] Solution preparation:

[0072] Solvent: dimethyl sulfoxide.

[0073] Reference substance positioning solution: accurately weigh approximately 3000 mg of methanol, 5000 mg of triethylamine, 410 mg of acetonitrile, 5000 mg of acetone, 600 mg of dichloromethane, and 880 mg of N,N-dimethylformamide, respectively, place in different 100 ml volumetric flasks, dilute to the scale with solvent, shake well, and prepare the reference substance positioning solution.

[0074] Reference solution: Take 1 ml of each reference solution and place it in a 100 ml volumetric flask, add solvent to dilute to the scale, shake well, and obtain the reference solution.

[0075] Take 1 μl of each of the above samples, inject into the gas chromatograph, and record the chromatogram. The results are shown in Table 1 and the spectrum is shown in Appendix. Figure 1 .

[0076] Table 1 Residual solvent method validation - mixed solution test results

[0077]

[0078] The results show that this method has good separation of each solvent (except triethylamine), appropriate peak elution time, and good peak shape (triethylamine has serious tailing, and it is considered to replace the chromatographic column to control triethylamine separately in the future). Therefore, this method is temporarily used as the residual solvent detection method for this product for subsequent verification.

[0079] Example 2 Detection Method Verification - Specificity

[0080] Solvent: dimethyl sulfoxide.

[0081] Reference substance stock solution: Weigh approximately 300 mg of methanol, 41 mg of acetonitrile, 500 mg of acetone, 60 mg of dichloromethane, and 88 mg of N,N-dimethylformamide respectively, accurately weigh them, place them in different 100 ml volumetric flasks, add solvent to dilute to the scale, shake well, and use them as reference substance stock solution.

[0082] Triethylamine reference stock solution: Weigh about 500 mg of triethylamine, accurately weigh it, place it in a 100 ml volumetric flask, add water to dilute to the scale, shake well, and use it as the triethylamine reference stock solution.

[0083] Mixed solution: Accurately measure 5 ml of each reference substance stock solution and triethylamine reference substance stock solution, place them in the same 50 ml volumetric flask, add solvent to dilute to the scale, shake well, and use as the mixed solution.

[0084] Reference substance solution: Accurately measure 5 ml of each reference substance stock solution and place it in the same 50 ml volumetric flask. Add solvent to dilute to the scale and shake well to prepare the reference substance solution.

[0085] Positioning solution: Take the stock solution of each reference substance and the stock solution of triethylamine reference substance as the positioning solution.

[0086] Test solution: Take about 1.0g of the product, weigh accurately, place in a 10ml volumetric flask, add solvent to dissolve and dilute to the scale, shake well, and use as the test solution.

[0087] Take 1 μl of blank solvent, positioning solution, reference solution, mixed solution, and test solution respectively, inject them into the gas chromatograph, record the chromatogram, and examine the separation between the residual solvents. The results are shown in Table 2 and the spectrum is shown in the attached Figure 2 ~Attached Figure 3 .

[0088] Table 2 Residual solvent method validation - mixed solution test results

[0089]

[0090] Conclusion: The blank solvent does not interfere with the determination of residual solvents; the resolution of each peak is greater than 1.5, indicating that this method has good specificity.

[0091] Example 3 Detection Method Verification - Durability

[0092] In order to investigate the stability of the measurement results when the measurement conditions fluctuate slightly, the influence of changing the following conditions on the measurement results while keeping other conditions unchanged was investigated.

[0093] (1) Change the column flow rate by ±0.2 ml / min (1: 1.8 ml / min; 2: 2.2 ml / min).

[0094] (2) Change the starting column temperature by ±5°C (1: 30°C; 2: 40°C).

[0095] Solvent: dimethyl sulfoxide.

[0096] Reference substance stock solution: Weigh approximately 300 mg of methanol, 41 mg of acetonitrile, 500 mg of acetone, 60 mg of dichloromethane, and 88 mg of N,N-dimethylformamide, accurately weigh them, place them in different 100 ml volumetric flasks, add solvent to dilute to the scale, shake well, and use them as reference substance stock solution.

[0097] Reference substance solution: Accurately measure 5 ml of each reference substance stock solution and place it in the same 50 ml volumetric flask. Add solvent to dilute to the scale and shake well to prepare the reference substance solution.

[0098] Test solution: Take about 1.0g of the product, weigh accurately, place in a 10ml volumetric flask, add solvent to dissolve and dilute to the scale, shake well, and use as the test solution.

[0099] Accurately measure 1 μl of blank solvent, reference solution and test solution, inject them into gas chromatograph, and record the chromatogram.

[0100] The experiment changed the column flow rate and the initial column temperature in the chromatographic conditions, and used the separation between the peaks of the residual solvents in the reference solution as an indicator, and the change in the residual solvent inspection amount (external standard method) in the test solution as an indicator to investigate the durability of the method. The results are shown in Tables 3 and 4.

[0101] Table 3 Residual solvent method validation - durability test system suitability separation results

[0102]

[0103] Conclusion: When the column flow rate was changed to 1.8ml / min and 2.2ml / min and the initial column temperature was 30℃ and 40℃, the blank solvent did not interfere with the determination; in the reference solution, the separation degree of each peak was greater than 1.5.

[0104] Table 4 Residual solvent method validation - Durability test test sample solution results

[0105]

[0106]

[0107] Note: “*” represents normal conditions

[0108] Conclusion: When the column flow rate was changed to 1.8ml / min and 2.2ml / min and the initial column temperature was 30℃ and 40℃, the number of residual solvents detected in the test solution was consistent according to the external standard method, and the range of each residual solvent content was less than 0.02%, indicating that the column flow rate was 1.8ml / min~2.2ml / min and the initial column temperature was in the range of 30℃~40℃, and the method had good durability.

[0109] Example 4 Detection Method Verification - Linearity and Range

[0110] Solvent: dimethyl sulfoxide.

[0111] Linear stock solution: Take about 300 mg of methanol, about 500 mg of acetone, about 60 g of dichloromethane, about 41 mg of acetonitrile, and about 88 mg of N,N-dimethylformamide, accurately weigh them, put them in the same 100 ml volumetric flask, add solvent to dilute to the scale, shake well, and use them as linear stock solution.

[0112] Linear solution: Accurately measure 0.1ml, 0.2ml, 0.5ml, 0.8ml, 1ml, and 1.5ml of the linear stock solution and place them in different 10ml volumetric flasks respectively. Add solvent to dilute to the scale and shake well to prepare linear solutions 1 to 6.

[0113] Accurately take 1 μl of each linear solution 1 to 6, inject into the gas chromatograph, record the chromatogram, and perform linear regression with concentration as the horizontal axis and peak area as the vertical axis. The results are shown in Table 5. The linear correlation diagrams are shown in the attached Figure 4 ~Attached Figure 8 .

[0114] Table 5 Residual solvent method validation - linearity test results

[0115]

[0116]

[0117] Note:

[0118]

[0119] Conclusion: Acetone: y = 1,517,540x-10,918,390, r = 0.9999, range: 51.320μg / ml ~ 769.800μg / ml, ratio: 1.43; methanol: y = 977998x + 386382, r = 0.9998, range: 32.340μg / ml ~ 485.100μg / ml, ratio: 0.12; dichloromethane: y = 400,351x + 2,471,419, r = 0.9968, range :6.290μg / ml~94.350μg / ml, ratio: 9.11; acetonitrile: y=1,593,381x+2,290,489, r=0.9997, range: 4.440μg / ml~66.600μg / ml, ratio: 3.12; N,N-dimethylformamide: y=838,234x+1,310,689, r=0.9998, range: 11.270μg / ml~169.050μg / ml, ratio: 1.36;

[0120] The results showed that the correlation coefficients r of all solvents were greater than 0.990, the ratios were less than 25%, and the linear relationship of all solvents was good within the range of 10% to 150% of the concentration limit of the test solution.

[0121] Example 5 Detection Method Verification - Limit of Quantitation and Limit of Detection

[0122] Blank solvent: dimethyl sulfoxide.

[0123] The quantitative limit concentration was inferred based on the S / N value of the linear solution No. 1 under the "Linearity and Range" item and diluted step by step.

[0124] When the signal-to-noise ratio is about 10, the amount of solvent corresponding to it is the quantitative limit of the solvent, and when the signal-to-noise ratio is about 3, the amount of solvent corresponding to it is the detection limit of the solvent. Accurately measure 1 μl of the above dilution, inject it into the gas chromatograph, and record the chromatogram. The results are shown in Tables 6 and 7.

[0125] Table 6 Residual solvent method validation - quantitation limit results

[0126]

[0127] Table 7 Residual solvent method validation - detection limit results

[0128]

[0129]

[0130] Conclusion: Quantification limit: Acetone: 2.005ng, equivalent to 0.0020% of the test solution concentration; Methanol: 1.992ng, equivalent to 0.0020% of the test solution concentration; Dichloromethane: 3.050ng, equivalent to 0.0031% of the test solution concentration; Acetonitrile: 0.623ng, equivalent to 0.0006% of the test solution concentration; N,N-dimethylformamide: 1.824ng, equivalent to 0.0018% of the test solution concentration;

[0131] Detection limit: Acetone: 0.827 ng, equivalent to 0.0008% of the test solution concentration; Methanol: 0.560 ng, equivalent to 0.0006% of the test solution concentration; Dichloromethane: 0.915 ng, equivalent to 0.0009% of the test solution concentration; Acetonitrile: 0.208 ng, equivalent to 0.0002% of the test solution concentration; N,N-dimethylformamide: 1.368 ng, equivalent to 0.0014% of the test solution concentration.

[0132] The proposed inspection concentration of cefazolin sodium is 100mg / ml, and the detection limit of each solvent is between 0.208ng and 1.368ng, which is equivalent to 0.0002% to 0.0014% of the test sample concentration, which can be effectively detected. The detection limit concentration of each solvent is less than 1 / 5 of the limit concentration; the quantitative limit of each solvent is between 0.623ng and 3.050ng, which is equivalent to 0.0006% to 0.0031% of the test sample concentration, which can be effectively quantified. The quantitative limit concentration of each solvent is less than 1 / 2 of the limit concentration. The results show that this method has high sensitivity.

[0133] Example 6 Detection Method Verification - Injection Precision and Repeatability

[0134] Solvent: dimethyl sulfoxide.

[0135] Mixed stock solution: Take about 300 mg of methanol, about 500 mg of acetone, about 60 mg of dichloromethane, about 41 mg of acetonitrile, and about 88 mg of N,N-dimethylformamide, accurately weigh them, put them in the same 100 ml volumetric flask, add solvent to dilute to the scale, shake well, and obtain.

[0136] Reference solution: Accurately measure 1 ml of the mixed stock solution and place it in a 10 ml volumetric flask. Add solvent to dilute to the mark and shake well.

[0137] Test solution: Take about 1.0g of the product, weigh accurately, put it in a 10ml volumetric flask, add solvent to dissolve and dilute to the scale, shake well, and prepare 6 copies in parallel.

[0138] Accurately measure 1 μl of blank solvent, reference solution and test solution, inject into gas chromatograph, record chromatogram, and calculate the residual solvent test amount in the test solution by external standard method. The results are shown in Table 8 and Table 9.

[0139] Table 8 Residual solvent method validation - injection precision test results

[0140]

[0141] Conclusion: The RSD of each solvent peak area was less than 10.0%, indicating that the instrument had good precision.

[0142] Table 9 Residual solvent method validation - repeatability test results

[0143]

[0144] Conclusion: The RSD of each solvent detection amount was less than 10.0%, indicating good repeatability.

[0145] Example 7 Detection Method Verification - Accuracy

[0146] Solvent: dimethyl sulfoxide.

[0147] Original quantity: Use the result data of “repeat experiment”.

[0148] Mixed stock solution: Weigh approximately 300 mg of methanol, 41 mg of acetonitrile, 500 mg of acetone, 60 mg of dichloromethane, and 88 mg of N,N-dimethylformamide respectively, accurately weigh them, place them in the same 100 ml volumetric flask, add solvent to dilute to the scale, shake well, and use as the mixed stock solution.

[0149] Reference solution: Accurately measure 1 ml of the mixed stock solution and place it in the same 10 ml volumetric flask. Add solvent to dilute to the scale and shake well as the reference solution.

[0150] Low concentration test solution (80%): Take about 1.0g of the product, weigh accurately, place in a 10ml volumetric flask, add 0.8ml of mixed stock solution, an appropriate amount of solvent, shake to dissolve, dilute to scale, shake well, as 80% test solution. Prepare 3 copies in parallel.

[0151] Medium concentration test solution (100%): Take about 1.0g of the product, weigh accurately, put it in a 10ml volumetric flask, add 1.0ml of mixed stock solution and an appropriate amount of solvent, shake to dissolve, and dilute to the scale, shake well, as the 100% test solution. Prepare 3 copies in parallel.

[0152] High concentration test solution (120%): Take about 1.0g of the product, weigh accurately, place in a 10ml volumetric flask, add 1.2ml of mixed stock solution, appropriate amount of solvent, shake to dissolve, dilute to scale, shake well, as 120% test solution. Prepare 3 copies in parallel.

[0153] Accurately measure 1 μl of blank solvent, reference solution and test solution, inject into gas chromatograph, record chromatogram, and calculate the residual solvent test amount in the test solution by external standard method. The results are shown in Table 10.

[0154] Table 10 Residual solvent method validation - accuracy test results

[0155]

[0156]

[0157]

[0158] Conclusion: The recovery rate is in the range of 80% to 120%. Calculated by external standard method: the recovery rate of each solvent is in the range of 92.55% to 116.13%, and the RSD is less than 10.0%, indicating that this method has good accuracy.

[0159] Example 8 Detection Method Verification - Intermediate Precision

[0160] Solvent: dimethyl sulfoxide.

[0161] Mixed stock solution: Take about 300 mg of methanol, about 500 mg of acetone, about 60 mg of dichloromethane, about 41 mg of acetonitrile, and about 88 mg of N,N-dimethylformamide, accurately weigh them, put them in the same 100 ml volumetric flask, add solvent to dilute to the scale, shake well, and obtain.

[0162] Reference solution: Accurately measure 1 ml of the mixed stock solution, place it in a 10 ml volumetric flask, add solvent to dilute to the scale, shake well, and obtain.

[0163] Test solution: Take about 1.0g of the product, weigh accurately, put it in a 10ml volumetric flask, add solvent to dissolve and dilute to the scale, shake well, and prepare 6 copies in parallel.

[0164] Different personnel, at different times, use different instruments to determine the repeatability test method. Accurately measure 1 μl of blank solvent, reference solution, and test solution, inject into gas chromatograph, record chromatogram, and calculate the residual solvent test amount in the test solution by external standard method. The results are shown in Table 11.

[0165] Table 11 Residual solvent method validation - repeatability and intermediate precision test results

[0166]

[0167]

[0168] Conclusion: The RSD of each solvent detection amount was less than 10.0%, and the results showed that this method had good precision.

Claims

1. A method for detecting residual solvents in cefazolin sodium, characterized in that: It adopts gas chromatography detection by headspace injection, records the chromatogram, and uses external standard method to conduct quantitative analysis on the spectrum; Among them, the detection conditions of the chromatography are: Instrument: Gas chromatograph; Chromatographic column: a capillary column with polyethylene glycol (or similar polarity) as the stationary phase or a gas phase capillary column with equivalent performance; Detector: hydrogen flame ionization detector (FID); carrier gas: nitrogen; Inlet temperature: 200°C; Detector temperature: 250°C; Heating program: the starting temperature is in the range of 30℃~40℃, maintained for 5 minutes, and then increased to 200℃ at a rate of 10℃ per minute, and maintained for 2 minutes; Injection volume: 1μl.

2. The method for detecting residual solvents in cefazolin sodium according to claim 1, characterized in that: The detection process is as follows: (1) Solution preparation: (a) Solvent: dimethyl sulfoxide; (b) Test solution: take about 1.0 g of the product, accurately weigh it, put it in a 10 ml volumetric flask, add solvent to dissolve and dilute to the scale, shake well, and use it as the test solution; (c) Reference solution: accurately weigh appropriate amounts of methanol, acetonitrile, acetone, dichloromethane, and N,N-dimethylformamide, add solvent to dissolve and dilute to make a mixed solution containing about 300 μg of methanol, 41 μg of acetonitrile, 500 μg of acetone, 60 μg of dichloromethane, and 88 μg of N,N-dimethylformamide per 1 ml, and use it as the reference solution; (2) Determination method: Take 1 μl of the reference solution, inject it into the gas chromatograph, and record the chromatogram; calculate the contents of residual solvents such as acetone, methanol, dichloromethane, acetonitrile, and N,N-dimethylformamide by peak area according to the external standard method.

3. The method for detecting residual solvent in cefazolin sodium according to claim 1, characterized in that: The peaks are acetone, methanol, dichloromethane, acetonitrile and N,N-dimethylformamide in order.

4. The method for detecting residual solvents in cefazolin sodium according to claim 1, characterized in that: The external standard method calculation formula is: Where: As is the peak area of ​​the corresponding residual solvent in the test solution; Wr is the weight of the reference substance, mg; Ar is the peak area of ​​the corresponding reference solvent in the reference solution; Ws is the weight of the test sample, mg; Sr is the dilution multiple of the reference solution; Ss is the dilution factor of the test solution.

5. The method for detecting residual solvent in cefazolin sodium according to claim 1, characterized in that: The specification of the chromatographic column is DB-WAX, 30m×0.32mm×1.0μm, or a capillary chromatographic column with equivalent performance.

6. The method for detecting residual solvent in cefazolin sodium according to claim 1, characterized in that: The column flow rate varies in the range of 1.8 ml / min to 2.2 ml / min.

7. The method for detecting residual solvent in cefazolin sodium according to claim 6, characterized in that: The column flow rate was 2 ml / min.

8. The method for detecting residual solvents in cefazolin sodium according to claim 1, characterized in that: The split ratio is 5:

1.

9. The method for detecting residual solvents in cefazolin sodium according to claim 1, characterized in that: The starting column temperature is preferably 35°C.

10. A method for detecting residual solvents in cefazolin sodium according to any one of claims 1 to 9, and use thereof in detecting the content of residual solvents in cefazolin sodium bulk drug or preparation.

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