Method for determining peroxide content in N-methyl pyrrolidone auxiliary material

Abstract

The invention discloses a method for determining the content of peroxide in an N-methyl pyrrolidone auxiliary material, and relates to the technical field of pharmaceutical analysis. The method comprises the following steps: preparing a reference solution and a test solution; injecting the reference solution and the test solution into a liquid chromatograph for detection; and calculating the peroxide content in the N-methyl pyrrolidone auxiliary material according to the detection result. The diluent is acetonitrile; chromatographic conditions of the detection are as follows: a chromatographic column is a C8 chromatographic column; a mobile phase is acetonitrile and water for gradient elution; the flow velocity is 0.5 to 2.0 mL / min; the sample size is 5-20 [mu] L; the detection wavelength is 200 to 250 nm; the column temperature is 20-40 DEG C; according to the method, the detection limit is 0.1 * 10 <-3 > mmol / L, the quantification limit is 0.3 * 10 <-3 > mmol / L, and a good linear relation is shown in the concentration range of 0.0003-0.218 mmol / L.

Description

Technical Field

[0001] The present invention relates to the technical field of pharmaceutical analysis, and in particular to a method for determining the peroxide content in N-methylpyrrolidone excipients. Background Art

[0002] In-situ precipitation implant systems have attracted much attention in the field of sustained and controlled-release injections in recent years. In this system, a drug and a water-insoluble polymer are dissolved or dispersed in a hydrophilic organic solvent, and then locally administered subcutaneously. At this time, the polymer will solidify under physiological conditions to form a semi-solid or solid drug depot. The in-situ precipitation implant system overcomes many disadvantages of ordinary emulsions, liposomes, microspheres, and micelles, and has many advantages such as local administration targeting the diseased site, prolonging the drug release period, reducing the dosage and drug adverse reactions, avoiding the pain caused by the implantation of implants by surgery, and relatively simple process.

[0003] In-situ precipitation implant systems all include organic solvents, and the types of organic solvents include N-methylpyrrolidone (NMP), ethanol, benzyl alcohol, dimethyl sulfoxide, etc. Among them, NMP is the most commonly used and can dissolve both hydrophilic biopolymer drugs and lipophilic polymer materials at the same time. However, NMP contains peroxides, and the content will continuously increase with the long-term storage after the reagent is opened, causing oxidation reactions of the active pharmaceutical ingredient (API) or other excipients. To effectively inhibit the oxidative degradation of the drug API, it is necessary to monitor and study its peroxide content.

[0004] The main detection methods for peroxide content include iodometric titration method, ultraviolet spectrophotometer method, potentiometric titration method, gas-phase derivatization chromatography method, horseradish peroxidase colorimetric method, etc.

[0005] The iodometric titration method (Chinese Pharmacopoeia 2020 Edition, Part IV) is a conventional detection method, and this method is used for the inspection item of oxidizing substances in potato starch. However, since the ability of NMP to complex with iodine is stronger than that of starch, NMP produces a yellow complex when encountering iodine, completely covering the color reaction of starch and iodine turning blue, and it is impossible to judge the titration end point. Therefore, it is not suitable for the determination of peroxide content in NMP.

[0006] Another relatively classic method for detecting peroxide value is the spectrophotometry method (Chinese Pharmacopoeia 2020 Edition, Part IV, General Rule 0401), and this method is used for the determination of peroxide content in povidone excipients. However, the detection sensitivity of this method is low, and it cannot meet the quantitative requirements for excipients with low peroxide value. Therefore, it is not suitable for the determination of peroxide content in NMP.

[0007] The peroxide content in NMP can be quantitatively detected by nuclear magnetic resonance (NMR) method. NMP is affected by oxygen in the air, and the peroxidation reaction mainly occurs on the carbon adjacent to the carbonyl group, and the product is 5-hydroperoxy-1-methyl-2-pyrrolidone. This peroxide functional group has a hydrogen atom, which shows a characteristic chemical shift on the NMR spectrum. The growth trend of peroxides in NMP is studied by monitoring the change of peak intensity. However, the detection sensitivity of this method is not high. In addition, NMR is not a common instrument in ordinary analysis laboratories, and its popularization and use have great limitations.

[0008] Literature 1 (Hu Junming, Shi Wenpeng, Lin Shaobin. Study on the determination of hydrogen peroxide in cosmetics by high performance liquid chromatography [J]. Chinese Journal of Health Laboratory Technology, 2003, (05): 593-596.) uses high performance liquid chromatography to determine hydrogen peroxide in cosmetics. The hydrogen peroxide in the sample to be measured is derivatized with triphenylphosphine to form triphenylphosphine oxide, and then analyzed and quantified by high performance liquid chromatography. The chromatographic column of this method is Φ4.6×250mm C 8 column; the mobile phase is acetonitrile + water = 60 + 40, gradient elution; the flow rate is 1.0 mL / min; the column temperature is room temperature; the detector is a photodiode array detector (PDA); the detection wavelength is 225 nm. This method has good correlation (γ > 0.9990), the relative standard deviation RSD of sample determination < 5%, the spiked recovery rate is 99.3% - 103.7%, and the detection limit is 1.7×10 -5 mol / L, but the correlation, relative standard deviation RSD of sample determination and detection limit of this detection method are all inferior to those of the present invention.

[0009] Literature 2 (Wang Ren, Wu Yuanyang, Cheng Qiaoyuan, etc. Establishment of a rapid method for the determination of hydrogen peroxide in hair dyes by on-line pre-column automatic derivatization - high performance liquid chromatography [J]. Chinese Journal of Pharmaceutical Analysis, 2019, 39(06): 1148-1153. DOI: 10.16155 / j.0254-1793.2019.06.25.) established a rapid method for the determination of hydrogen peroxide in cosmetics by on-line pre-column automatic derivatization - high performance liquid chromatography, and compared the methodology with the high performance liquid chromatography pre-column derivatization method in the "Cosmetics Safety and Technology Specifications" (2015 edition). At the same time, the hydrogen peroxide content in 3 different brands of hair dyes was compared, and the last step of the derivatization step in the "Cosmetics Safety and Technology Specifications" (2015 edition) was changed from volume fixation with water to volume fixation with acetonitrile. The chromatographic column of this method is ZORBAX SB-C 18(4.6 mm × 250 mm, 5 μm); the mobile phase is acetonitrile - ultrapure water (60:40); the flow rate is 1.0 mL / min; the detection wavelength is 225 nm; the injection volume is 10 μL; the column temperature is 35 °C. This method uses on - line pre - column automatic derivation - high performance liquid chromatography to rapidly detect hydrogen peroxide in cosmetics. The results are reliable, the method is feasible, and it is suitable for application in cosmetics inspection work. However, the correlation of this detection method is inferior to that of the present invention.

[0010] In view of this, to solve the deficiency of low sensitivity in the existing technology detection method, the present invention provides a method for determining the peroxide content in N - methylpyrrolidone excipients. Summary of the Invention

[0011] The object of the present invention is to provide a method for determining the peroxide content in N - methylpyrrolidone excipients, which omits the step of calibrating hydrogen peroxide, simplifies the operation steps, and improves the accuracy.

[0012] To achieve the above - mentioned invention object, the technical solution of the present invention is as follows:

[0013] On the one hand, the present invention provides a method for determining the peroxide content in N - methylpyrrolidone excipients, including the following steps:

[0014] S1. Prepare a reference solution and a test solution;

[0015] S2. Inject the reference solution and the test solution into a liquid chromatograph for detection;

[0016] S3. Calculate the peroxide content in the N - methylpyrrolidone excipient according to the detection result;

[0017] In step S1, the diluent is acetonitrile;

[0018] In step S2, the chromatographic conditions for the detection are: the chromatographic column is a C 8 chromatographic column; the mobile phase is gradient elution of acetonitrile and water; the flow rate is 0.5 - 2.0 mL / min; the injection volume is 5 - 20 μL; the detection wavelength is 200 - 250 nm; the column temperature is 20 - 40 °C.

[0019] Preferably, in step S1, the solute of the reference solution is triphenylphosphine oxide and the solvent is acetonitrile.

[0020] Further preferably, in step S1, the concentration of the reference solution is 0.01 - 0.5 mmol / L.

[0021] Even more preferably, in step S1, the concentration of the reference solution is 0.05 mmol / L.

[0022] Preferably, in step S1, the steps of preparing the test sample solution are as follows: Mix N-methylpyrrolidone excipient, triphenylphosphine derivative solution and acetonitrile, completely dissolve to form a solution, and place it in the dark to stand for derivatization for 40-100 min.

[0023] More preferably, in step S1, the triphenylphosphine derivative solution is an acetonitrile solution of triphenylphosphine, and the concentration of triphenylphosphine is 0.0001-0.01 g / mL.

[0024] Even more preferably, in step S1, the concentration of triphenylphosphine is 0.001 g / mL.

[0025] Even more preferably, in step S1, the ratio of the N-methylpyrrolidone excipient, the triphenylphosphine derivative solution and the test sample solution is 0.01-1 g: 0.1-10 mL: 1-100 mL.

[0026] Even more preferably, in step S1, the ratio of the N-methylpyrrolidone excipient, the triphenylphosphine derivative solution and the test sample solution is 0.1 g: 1 mL: 10 mL.

[0027] Preferably, in step S2, the flow rate is 1.0 mL / min.

[0028] Preferably, in step S2, the injection volume is 10 μL.

[0029] Preferably, in step S2, the detection wavelength is 225 nm.

[0030] Preferably, in step S2, the column temperature is 30 °C.

[0031] Preferably, in step S2, the gradient elution of acetonitrile and water is specifically as follows: at 0 min, water: acetonitrile = 50:50; at 7 min, water: acetonitrile = 50:50; at 7.1 min, water: acetonitrile = 5:95; at 12 min, water: acetonitrile = 5:95; at 12.1 min, water: acetonitrile = 50:50; at 17 min, water: acetonitrile = 50:50.

[0032] On the other hand, the present invention provides the application of the above method in drug quality evaluation or quality control.

[0033] Finally, the present invention provides a method for drug quality evaluation or quality control, including the above method.

[0034] The beneficial effects of the present invention are as follows:

[0035] (1) The present invention discloses a method for determining the peroxide content in N-methylpyrrolidone excipient. The detection limit of the method is 0.1×10 -3 mmol / L, and the quantification limit is 0.3×10-3 mmol / L, showing a good linear relationship within the concentration range of 0.0003 - 0.218 mmol / L, with a correlation coefficient R 2 = 0.9999.

[0036] (2) The present invention discloses a method for determining the peroxide content in N-methylpyrrolidone excipients. The method omits the step of calibrating hydrogen peroxide, simplifies the operation steps, and improves the accuracy. Description of the Drawings

[0037] Figure 1 It is the specificity chromatogram of the detection method disclosed in Example 1.

[0038] Figure 2 It is the standard curve of the detection method disclosed in Example 1.

[0039] Figure 3 It is the result graph of the rate of TPPO generation in the blank solutions in Example 1, Comparative Examples 1 - 3.

[0040] Figure 4 It is the result graph of the influence of the derivatization time of the sample solution in Example 1 on the peak area.

[0041] Figure 5 It is the chromatogram of Example 1. Among them, the upper chromatogram is the complete version, and the lower chromatogram is the partially enlarged version.

[0042] Figure 6 It is the chromatogram of Comparative Example 4. Among them, the upper chromatogram is the complete version, and the lower chromatogram is the partially enlarged version.

[0043] Figure 7 It is the chromatogram of Comparative Example 5. Among them, the upper chromatogram is the complete version, and the lower chromatogram is the partially enlarged version.

[0044] Figure 8 It is the chromatogram of Comparative Example 6. Among them, the upper chromatogram is the complete version, and the lower chromatogram is the partially enlarged version.

[0045] Figure 9 It is the result graph of the change in peroxide value after NMP is opened and placed open using the detection method disclosed in Example 1. Detailed Embodiments

[0046] The following non-limiting examples can enable those of ordinary skill in the art to more comprehensively understand the present invention, but do not limit the present invention in any way. The following content is merely an exemplary illustration of the scope claimed by the present invention. Those skilled in the art can make various changes and modifications to the present invention based on the disclosed content, and such changes and modifications should also fall within the scope claimed by the present invention.

[0047] The present invention will be further described below by way of specific examples. All chemical reagents used in the examples of the present invention are obtained through conventional commercial channels unless otherwise specified. Unless otherwise specified, the contents described below are mass contents. Unless otherwise specified, it is understood that the operations are carried out at room temperature.

[0048] Experimental materials and instruments

[0049] Liquid chromatograph: Huapu Keji S6000 high-performance liquid chromatograph;

[0050] Detector: The type is a diode array detector, the manufacturer is Huapu Keji, and the model is 6430;

[0051] Chromatographic column: AglientZorbaxRX-C 8 4.6×250mm, 5μm;

[0052] Acetonitrile: The manufacturer is RiMedCo, batch number: 959234, grade: HPLC;

[0053] Triphenylphosphine (TPP): The manufacturer is Adamas-beta, batch number: P2986930, grade: analytical pure;

[0054] Triphenylphosphine oxide (TPPO): The manufacturer is Adamas-beta, batch number: P2998766, grade: analytical pure;

[0055] Sample: N-methylpyrrolidone (NMP), Adamas-beta, batch number: P3045493, grade: HPLC.

[0056] Example 1

[0057] A method for determining the peroxide content in N-methylpyrrolidone excipients, comprising the following steps:

[0058] 1. Solution preparation

[0059] Diluent: Acetonitrile;

[0060] NMP solution: Weigh 0.1 g of the sample precisely into a 10 mL brown volumetric flask, and make up to the mark with the diluent and mix well;

[0061] TPP derivative solution: Weigh 0.05 g of TPP precisely into a 50 mL volumetric flask, and make up to the mark with diluent and mix well;

[0062] TPPO stock solution (0.5 mmol / L): Weigh 0.06 g of TPPO standard precisely into a 200 mL volumetric flask, and make up to the mark with diluent and mix well;

[0063] Control solution (0.05 mmol / L): Dilute the TPPO stock solution 10 times to a solution with a concentration of 30 μg / mL, and make up to the mark with diluent and mix well;

[0064] Sample solution to be measured: Weigh 0.1 g of the sample precisely into a 10 mL brown volumetric flask, add 1 mL of TPP derivative solution, make up to the mark with diluent and mix well, and let it stand in the dark for 40 min for derivatization;

[0065] Blank solution: In a 10 mL brown volumetric flask, add 1 mL of TPP derivative solution, make up to the mark with diluent and mix well, and let it stand in the dark for 40 min for derivatization.

[0066] 2. Chromatographic conditions

[0067] Chromatographic column: Aglient Zorbax RX-C 8 4.6×250 mm, 5 μm;

[0068] Mobile phase: Gradient elution with acetonitrile and water, and the gradient elution conditions are shown in Table 1;

[0069] Flow rate: 1.0 mL / min;

[0070] Injection volume: 10 μL;

[0071] Detection wavelength: 225 nm;

[0072] Column temperature: 30 °C;

[0073] Running time: 17 min.

[0074] Table 1

[0075] Time min Mobile phase A (water) % Mobile phase B (acetonitrile) % 0 50 50 7 50 50 7.1 5 95 12 5 95 12.1 50 50 17 50 50

[0076] 3. Calculate the peroxide content in the N-methylpyrrolidone auxiliary material according to the detection results

[0077] Precisely measure and inject the control solution and the sample solution to be measured into the liquid chromatograph respectively, and perform detection according to the above chromatographic conditions, record the chromatogram, and calculate the peroxide content by the external standard method based on the peak area. The calculation formula is:

[0078]

[0079] In the formula:

[0080] The peroxide value is the molar amount of active oxygen in 1 kg of the sample, mmol / kg;

[0081] c is the measured concentration of TPPO in the sample solution to be measured, mmol / L;

[0082] c 0 is the measured concentration of TPPO in the blank solution, mmol / L;

[0083] m is the weighed amount of the sample to be measured, g;

[0084] V is the dilution volume of the sample to be measured, mL.

[0085] Comparative Example 1

[0086] A method for determining the peroxide content in N-methylpyrrolidone excipients, comprising the following steps:

[0087] 1. Solution preparation

[0088] Diluent: The volume ratio of acetonitrile and H 2 O is 5:5;

[0089] TPP derivative solution: Weigh 0.05 g of TPP precisely into a 50 mL volumetric flask, and make up to the mark with acetonitrile and mix well;

[0090] Blank solution: In a 10 mL brown volumetric flask, add 1 mL of TPP derivative solution, 5 mL of high-purity water, make up to the mark with acetonitrile and mix well, and let it stand for derivatization in the dark for 40 min.

[0091] 2. Chromatographic conditions

[0092] Same as Example 1.

[0093] 3. Transfer the blank solution to a brown injection vial, place it at room temperature in the dark, and track and record the change in the peak area of TPPO in the blank solution over time.

[0094] Comparative Example 2

[0095] A method for determining the peroxide content in N-methylpyrrolidone excipients, comprising the following steps:

[0096] 1. Solution preparation

[0097] Diluent: The volume ratio of acetonitrile and H 2 O is 7:3;

[0098] TPP derivative solution: Weigh 0.05 g of TPP precisely into a 50 mL volumetric flask, and make up to the mark with acetonitrile and mix well;

[0099] Blank solution: In a 10 mL brown volumetric flask, add 1 mL of TPP derivative solution, 3 mL of high-purity water, and make up to the mark with acetonitrile. Mix well and let it stand in the dark for 40 min for derivatization.

[0100] 2. Chromatographic conditions

[0101] Same as Example 1.

[0102] 3. Transfer the blank solution to a brown injection vial, place it at room temperature in the dark, and track and record the change in the peak area of TPPO in the blank solution over time.

[0103] Comparative Example 3

[0104] A method for determining the peroxide content in N-methylpyrrolidone excipients, comprising the following steps:

[0105] 1. Solution preparation

[0106] Diluent: The volume ratio of acetonitrile to H 2 O is 9:1;

[0107] TPP derivative solution: Weigh accurately 0.05 g of TPP in a 50 mL volumetric flask, and make up to the mark with acetonitrile. Mix well.

[0108] Blank solution: In a 10 mL brown volumetric flask, add 1 mL of TPP derivative solution, 1 mL of high-purity water, and make up to the mark with acetonitrile. Mix well and let it stand in the dark for 40 min for derivatization.

[0109] 2. Chromatographic conditions

[0110] Same as Example 1.

[0111] 3. Transfer the blank solution to a brown injection vial, place it at room temperature in the dark, and track and record the change in the peak area of TPPO in the blank solution over time.

[0112] Comparative Example 4

[0113] A method for determining the peroxide content in N-methylpyrrolidone excipients, comprising the following steps:

[0114] 1. Solution preparation

[0115] Same as Example 1.

[0116] 2. Chromatographic conditions

[0117] Chromatographic column: AglientZorbaxRX-C 18 4.6×250 mm, 5 μm;

[0118] Other chromatographic conditions are the same as in Example 1.

[0119] 3. Calculate the peroxide content in the N-methylpyrrolidone auxiliary material according to the test results

[0120] Same as Example 1

[0121] Comparative Example 5 (The chromatographic conditions are the same as those in Document 2)

[0122] 1. Solution preparation

[0123] Same as Example 1

[0124] 2. Chromatographic conditions

[0125] Chromatographic column: ZORBAX SB-C 18 (4.6 mm × 250 mm, 5 μm);

[0126] Mobile phase: acetonitrile - ultrapure water (60:40);

[0127] Flow rate: 1.0 mL / min;

[0128] Injection volume: 10 μL;

[0129] Detection wavelength: 225 nm;

[0130] Column temperature: 35 °C

[0131] 3. Calculate the peroxide content in the N-methylpyrrolidone auxiliary material according to the test results

[0132] Same as Example 1

[0133] Comparative Example 6 (The chromatographic conditions are the same as those in Document 1)

[0134] 1. Solution preparation

[0135] Same as Example 1

[0136] 2. Chromatographic conditions

[0137] Chromatographic column: Aglient Zorbax RX-C 8 4.6 × 250 mm, 5 μm;;

[0138] Mobile phase: gradient elution with acetonitrile and water, and the gradient elution conditions are shown in Table 2;

[0139] Flow rate: 1.0 mL / min;

[0140] Injection volume: 10 μL;

[0141] Detection wavelength: 225 nm;

[0142] Column temperature: room temperature

[0143] Table 2

[0144] Time min Mobile phase A (acetonitrile) % Mobile phase B (water) % 0 60.0 40.0 7.0 60.0 40.0 8.0 100.0 0.0 13.0 100.0 0.0 15.0 60.0 40.0

[0145] 3. Calculate the peroxide content in the N-methylpyrrolidone auxiliary material according to the test results

[0146] Same as Example 1

[0147] Results and Discussion

[0148] 1. Method validation data

[0149] 1.1 Specificity

[0150] Take the diluent, NMP solution, and test sample solution in Example 1 respectively for liquid chromatography detection. The chromatographic conditions are the same as those in Example 1. The chromatographic results of the test sample after derivation are shown in Figure 1 , Figure 1 . It is observed that the retention times of NMP, TPPO, and TPP are 2.89 min, 7.21 min, and 12.78 min respectively. The above experimental results show that the solvent, reactants, and derivatization reagents do not interfere with the chromatographic signal of the derivatized product TPPO, and the specificity is strong

[0151] 1.2 Accuracy

[0152] Prepare 6 portions of the test sample solution in Example 1 for liquid chromatography detection. The chromatographic conditions are the same as those in Example 1. The results are shown in Table 3, and the RSD% of the peroxide value = 1.4% (n = 6)

[0153] Table 3

[0154]

[0155] To further investigate the accuracy of the detection method disclosed in Example 1, the same hydrogen peroxide solution was used to compare the detection method disclosed in Example 1 and the traditional iodometric titration method. The experimental results are as follows: the measured value of the iodometric titration method is 5.5 mmol / kg, and the measured value of the detection method disclosed in Example 1 is 5.1 mmol / kg. It can be seen that the measured values of the two detection methods are basically the same

[0156] In summary, it shows that the detection method disclosed in Example 1 has high accuracy

[0157] 1.3 Detection limit and quantification limit

[0158] Take the TPPO stock solution in Example 1 and dilute it step by step. The detection limit is obtained as 0.1×10 - 3 mmol / L based on the signal-to-noise ratio (S / N≥3); the quantification limit is obtained as 0.3×10 -3mmol / L. The sample was continuously injected 6 times at the limit of quantitation, and the test results are shown in Table 4. The RSD% of the peak area = 1.5% (n = 6).

[0159] Table 4

[0160]

[0161] The detection limit of the detection method disclosed in Example 1 is 0.1×10 -3 mmol / L, and the limit of quantitation is 0.3×10 -3 mmol / L.

[0162] In the detection method disclosed in Example 1, 0.1 g of the sample was diluted to 10 mL. The lowest detectable concentration of peroxide was 0.01 mmol / kg, and the lowest quantitation concentration was 0.03 mmol / kg.

[0163] 1.4. Linearity and range

[0164] The TPPO stock solution in Example 1 was successively diluted with acetonitrile to prepare reference solutions with concentrations of 0.0003 mmol / L, 0.011 mmol / L, 0.055 mmol / L, 0.109 mmol / L, and 0.218 mmol / L. A standard curve was plotted with the TPPO peak area as the ordinate and the concentration (mmol / L) as the abscissa. The results are shown in Figure 2 . A good linear relationship was presented in the range of concentration from 0.0003 to 0.218 mmol / L. The regression equation was y = 14431689.0309x + 8799.7981, and the correlation coefficient R 2 = 0.9999.

[0165] 1.5. Solution stability

[0166] The test sample solution in Example 1 was taken and placed at room temperature in the dark for 8 hours to investigate the solution stability. The results are shown in Table 5, indicating that the derivatized sample solution remained stable within 8 hours.

[0167] Table 5

[0168]

[0169] 2. Rate of TPPO formation in the blank solution

[0170] The blank solutions in Example 1 and Comparative Examples 1 - 3 were detected by liquid chromatography under the same chromatographic conditions (see Example 1). A curve was plotted with the TPPO peak area as the ordinate and time as the abscissa. The results are shown in Figure 3 .

[0171] Since it is desired to accurately monitor the peroxide content of the auxiliary material NMP throughout the entire cycle, the diluent was screened based on the rate of TPPO generation in the blank solution in this study. Figure 3 It shows that when ACN is used as the diluent (Example 1), the change in the peak area of TPPO is the smallest, that is, the blank interference is the smallest and most controllable.

[0172] 3. Investigation of the derivatization time

[0173] After changing the derivatization time of the sample solution in Example 1, the sample solution was subjected to liquid chromatography detection. The chromatographic conditions are shown in Example 1, and the detection results are shown in Figure 4 , Figure 4 It shows that the sample solution can reach kinetic equilibrium after derivatization for 40 min.

[0174] 4. Chromatographic conditions

[0175] The detection chromatograms of Example 1 and Comparative Example 4 are as shown in Figure 5 and Figure 6 shown. The detection chromatogram of Comparative Example 4 shows severe peak tailing, the main peak baseline is raised, and the derivative product peak cannot be completely separated from the unknown impurity peak brought by the reactant. The detection chromatogram of Example 1 shows good peak shape and no interference from impurities.

[0176] The detection chromatograms of Example 1 and Comparative Example 5 are as shown in Figure 5 and Figure 7 shown. Under the same chromatographic conditions as in Document 2, using a C 18 chromatographic column, the derivative product peak appears at 4.3 min under the mobile phase of acetonitrile - ultrapure water (60:40), and the derivative product peak cannot be completely separated from the unknown impurity peak either, which is the same as Figure 6 consistent.

[0177] For Comparative Example 4 and Comparative Example 5, when using a C 18 chromatographic column, the problem of the baseline rising after the main peak appears, while using a C 8 chromatographic column can effectively improve this phenomenon.

[0178] The detection chromatograms of Example 1 and Comparative Example 6 are shown in Figure 5 and Figure 8 shown. Under the same chromatographic conditions as in Document 1, using a C 8 column gradient elution, when the initial mobile phase ratio is ACN:H 2 0 = 60:40, the resolution between the derivative product peak and the unknown impurity peak is not good. While when the initial mobile phase ratio is optimized to ACN:H 2 0 = 50:50, baseline separation can be achieved and the interference of the impurity peak can be eliminated.

[0179] 5. Change in peroxide value of NMP after opening and leaving it open

[0180] Using the detection method disclosed in Example 1, the peroxide value changes of the newly opened NMP reagent were detected after 0 days, 1 month, and 3 months of exposure to the air. The detection results are shown in Figure 9 . Figure 9 It shows that the peroxide value in NMP continuously increases after opening, growing from 6 mmol / kg at 0 days to 25 mmol / kg at 3 months. On the one hand, it indicates that there is a risk of continuous oxidation of NMP excipients over time and quality control is needed; at the same time, it also shows that the detection method disclosed in Example 1 can effectively track and monitor NMP peroxides.

[0181] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for determining the peroxide content in N-methylpyrrolidone auxiliary material, characterized in that: The following steps are involved: S1. Prepare reference solution and test solution; S2, injecting the reference solution and the test solution into a liquid chromatograph for detection; S3. Calculate the peroxide content in the N-methylpyrrolidone auxiliary material according to the test results; In step S1, the diluent is acetonitrile; In step S2, the chromatographic conditions for the detection are: the chromatographic column is a C8 chromatographic column; the mobile phase is acetonitrile and water gradient elution; the flow rate is 0.5-2.0mL / min; the injection volume is 5-20uL; the detection wavelength is 200-250nm; and the column temperature is 20-40°C.

2. The method according to claim 1, characterized in that In step S1, the solute of the reference solution is triphenylphosphine oxide, and the solvent is acetonitrile.

3. The method according to claim 2, characterized in that In step S1, the concentration of the reference solution is 0.01-0.5 mmol / L.

4. The method according to claim 1, characterized in that: In step S1, the steps of preparing the test solution are as follows: N-methylpyrrolidone auxiliary material, triphenylphosphine derivative liquid and acetonitrile are mixed, completely dissolved to form a solution, and placed in a dark place for derivatization for 40-100 minutes.

5. The method according to claim 4, characterized in that In step S1, the triphenylphosphine derivative solution is an acetonitrile solution of triphenylphosphine, and the concentration of triphenylphosphine is 0.0001-0.01 g / mL.

6. The method according to claim 5, characterized in that In step S1, the ratio of the N-methylpyrrolidone auxiliary material, the triphenylphosphine derivative solution and the test solution is 0.01-1g: 0.1-10mL: 1-100mL.

7. The method according to claim 1, characterized in that In step S2, the flow rate is 1.0 mL / min; the injection volume is 10 uL; the detection wavelength is 225 nm; and the column temperature is 30°C.

8. The method according to claim 1, characterized in that: In step S2, the gradient elution of acetonitrile and water is specifically: 0 min, water:acetonitrile=50:50, 7 min, water:acetonitrile=50:50, 7.1 min, water:acetonitrile=5:95, 12 min, water:acetonitrile=5:95, 12.1 min, water:acetonitrile=50:50, 17 min, water:acetonitrile=50:

50.

9. Use of the method according to any one of claims 1 to 8 in drug quality evaluation or quality control.

10. A method for drug quality evaluation or quality control, characterized in that: The method comprising any one of claims 1 to 8.

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