Pretreatment method and detection method for detecting impurities in carboxymaltose iron preparation

Abstract

This invention discloses a pretreatment method and a detection method for detecting impurities in carboxymaltose iron products. The pretreatment method for detecting impurities in carboxymaltose iron products includes the following steps: preparing a carboxymaltose iron product solution; treating the carboxymaltose iron product solution by ultrafiltration and centrifugation to retain carboxymaltose iron; and obtaining the filtrate from the ultrafiltration and centrifugation as the carboxymaltose test solution for detection; wherein the impurity is a sugar impurity. The pretreatment method for detecting impurities in carboxymaltose iron products provided by this invention can effectively remove carboxymaltose iron products by ultrafiltration, preventing damage to the chromatographic column and matrix interference during impurity detection.

Description

Technical Field

[0001] This invention relates to the field of pharmaceutical analysis technology, and in particular to a pretreatment method and detection method for detecting impurities in carboxymaltose iron products. Background Technology

[0002] Carboxymaltose iron is a third-generation iron supplement, belonging to the typical type I iron complex. It features stable properties and a strong ability to bind iron to its ligands. Compared to current mainstream iron supplements, carboxymaltose iron has similar iron utilization efficiency to sucrose iron, without the drawback of allergic reactions associated with dextran iron. Due to its stable iron ligand binding ability, carboxymaltose iron can release iron at a slow and controlled rate, significantly reducing the risk of iron poisoning caused by free radical generation.

[0003] Carboxymaltose iron is a high-molecular-weight complex composed of ferric hydroxide and maltodextrin. With ferric hydroxide as the core, a glycosidic ligand shell forms the outer layer. The main function of the glycosidic ligand shell is to stabilize the iron core, control iron release, and maintain the particles in a suspended colloidal state. After intravenous injection, carboxymaltose iron injection is precisely taken up by bone marrow macrophages and then slowly and orderly released as iron ions for the body's use. This minimizes free iron levels and reduces the occurrence of iron overload-related adverse reactions.

[0004] As a key component of carboxymethyl maltose iron, maltodextrin determines the release rate and bioavailability of iron in the human body. The structure of carboxymethyl maltose iron is as follows: Figure 1 As shown.

[0005] The organic impurities in this product mainly come from maltodextrin, which is a glucose polymer. In the process of preparing carboxymaltose iron, it may be hydrolyzed into glucose, and glucose can be converted into fructose under heating conditions.

[0006] As a raw material for high-molecular-weight colloidal injections, the safety and efficacy of carboxymaltose ferric sulfate are closely related to its structure and composition. To ensure the safety and efficacy of carboxymaltose ferric sulfate, finding a highly accurate and stable method for testing the glucose and fructose content is of great significance for its quality control. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to overcome the lack of a good method for detecting impurities in carboxymaltose iron products in the prior art. The present invention provides a pretreatment method and a detection method for detecting impurities in carboxymaltose iron products. The detection method using this pretreatment method can eliminate the influence of matrix interference.

[0008] This invention provides a pretreatment method for detecting impurities in carboxymaltose iron products. The carboxymaltose iron product is prepared into a carboxymaltose iron product solution, and the carboxymaltose iron product solution is treated by ultrafiltration centrifugation to retain carboxymaltose iron. The filtrate obtained by ultrafiltration centrifugation is the carboxymaltose test solution used for detection. The impurities are sugar impurities.

[0009] After research and preliminary experiments, the inventors concluded that chromatography is the most effective method for detecting glucose and fructose. High-performance liquid chromatography (HPLC) provides good separation of glucose and fructose; however, carboxymaltose iron has a large molecular weight and a particle size of approximately 30 nm, while the pore size of conventional HPLC column packing particles is... (i.e., 8-10 nm), etc. If the test solution is not treated as necessary and injected directly, it will lead to column blockage, increased column pressure, and some matrix interference; if the test solution is chemically treated, it may be impossible to accurately quantify the impurity content in carboxymaltose iron due to the degradation of glucose and / or fructose impurities.

[0010] Based on the above research, this invention proposes to use ultrafiltration centrifugation to retain carboxymethyl maltose iron. On the one hand, this can reduce the interference from the matrix, and on the other hand, it can reduce the adverse effects of macromolecular substances in the sample on the liquid chromatography detection system. At the same time, it can also enrich trace impurities, achieving better pretreatment results.

[0011] In this invention, preferably, the carboxymaltose iron product is carboxymaltose iron raw material or carboxymaltose iron injection.

[0012] Preferably, the carboxylated maltose iron active pharmaceutical ingredient is a solid, comprising the following components by weight percentage:

[0013] The iron content is 24%–32%; the maltodextrin content is 25%–50%; the fructose content is ≤0.5%; the glucose content is ≤0.5%; and the content of other impurities is 2.2%–17%, wherein the other impurities are selected from one or more of glycolic acid, formic acid, acetic acid, malonic acid, pyruvic acid, lactic acid, furfural, 5-hydroxymethylfurfural, 2-furanic acid, and 5-hydroxymethyl-2-furanic acid.

[0014] Preferably, the iron content in the carboxymaltose iron injection is 45-55 mg / mL, for example, 50 mg / mL.

[0015] In this invention, preferably, the carboxymaltose iron product has a weight-average molecular weight of 140-210 kDa.

[0016] In this invention, preferably, the solvent used in preparing the carboxymaltose iron product solution is water, and more preferably deionized water.

[0017] Preferably, when preparing the carboxymaltose iron product solution, the mass-to-volume ratio of the carboxymaltose iron product to the water is 3.8-160 g / L, for example, 0.1 g / L or 0.16 g / L.

[0018] In this invention, preferably, the sugar impurity is glucose and / or fructose, more preferably glucose and fructose.

[0019] In this invention, preferably, the tube body of the ultrafiltration centrifuge tube is made of polypropylene and / or styrene-butadiene; more preferably, the ultrafiltration centrifuge tube is a Merck Millipore UFC503008 ultrafiltration centrifuge tube; and even more preferably, the ultrafiltration centrifuge tube is an Amicon Ultra-0.5 centrifugal filter equipped with an Ultracel-30 filter membrane.

[0020] In this invention, preferably, the ultrafiltration membrane of the ultrafiltration centrifuge tube is made of regenerated cellulose membrane.

[0021] In this invention, preferably, the pore size of the ultrafiltration membrane in the ultrafiltration centrifuge tube is 30 kDa MWCO.

[0022] In this invention, preferably, the rotation speed of the ultrafiltration centrifuge tube during centrifugation is 3000-12000 rpm, for example, 6000 rpm, 8000 rpm or 10000 rpm.

[0023] In this invention, preferably, the centrifugation time of the ultrafiltration centrifuge tube is 5-20 minutes, for example, 5 minutes or 10 minutes.

[0024] In this invention, preferably, after ultrafiltration and centrifugation, the filtrate is used as the carboxymethyl maltose iron test solution.

[0025] This invention also provides a method for detecting impurities in carboxymaltose iron products, comprising the following steps:

[0026] S1. The carboxymethyl maltose iron test solution as described in any one of claims 1-3 is detected by high performance liquid chromatography (HPLC) to obtain the peak area corresponding to each impurity; the mobile phase of the HPLC is an acetonitrile-water-triethylamine system.

[0027] S2. Based on the peak areas corresponding to each impurity obtained in S1, the content of impurities in the carboxymaltose iron product is calculated using the external standard method.

[0028] In this invention, preferably, the chromatographic column of the high-performance liquid chromatography is an aminosilane-bonded silica column; the type of the chromatographic column of the high-performance liquid chromatography is, for example, Waters XBridge BEH Amide or Altima Amino.

[0029] In this invention, preferably, the length of the chromatographic column in the high-performance liquid chromatography method is 150-250 mm, for example, 250 mm.

[0030] In this invention, preferably, the inner diameter of the chromatographic column of the high performance liquid chromatography is 3.5-4.6 mm, for example 4.6 mm.

[0031] In this invention, preferably, the particle size of the packing material in the chromatographic column of the high-performance liquid chromatography (HPLC) is 3.5-5 μm, such as 5 μm. Preliminary experiments revealed that when the particle size of the selected chromatographic column packing material is too large (e.g., 8 μm), the resolution of various impurities is low, and the effect of impurity determination is poor; when the particle size of the selected chromatographic column packing material is too small (e.g., ≤3.5 μm), the column pressure is relatively high, which can easily damage the chromatographic column and cause greater interference from the sample matrix. Therefore, selecting packing material with a particle size of 3.5-5 μm provides better resolution, while selecting packing material with a particle size of 5 μm can better balance column pressure and resolution.

[0032] In a specific embodiment of the present invention, the chromatographic column of the high performance liquid chromatography method has a length of 250 mm and an inner diameter of 4.6 mm, and the particle size of the packing material in the chromatographic column is 5 μm.

[0033] In this invention, preferably, the detector used in the high-performance liquid chromatography is a differential refractive index detector. The detection conditions of the differential refractive index detector are conventional conditions.

[0034] Preferably, in the high performance liquid chromatography method, the temperature of the differential refractive index detector is 33-37°C, for example, 35°C.

[0035] In this invention, preferably, the volume ratio of the acetonitrile, the water, and the triethylamine in the mobile phase is (745-755):(245-255):2, for example, 750:250:2.

[0036] In this invention, preferably, the elution method of the high performance liquid chromatography is isocratic elution.

[0037] In this invention, preferably, in the high performance liquid chromatography method, the flow rate of the mobile phase is 0.9-1.1 mL / min, for example, 1.0 mL / min.

[0038] In this invention, preferably, in the high performance liquid chromatography method, the injection volume of the carboxymaltose iron test solution is 5-100 μL, for example 15 μL.

[0039] In this invention, preferably, the temperature of the chromatographic column in the high-performance liquid chromatography is 33-37°C, for example, 35°C.

[0040] In this invention, preferably, in the method for detecting impurities in the carboxymaltose iron product, the impurity is glucose, and the detection limit of glucose is 0.12 g / L.

[0041] In this invention, preferably, in the method for detecting impurities in the carboxymaltose iron product, the impurity is fructose, and the detection limit of fructose is 0.12 g / L.

[0042] In this invention, preferably, in step S2, the content of impurities in the carboxymaltose iron product is calculated using the external standard method based on the standard curve of the impurities; more preferably, the method for preparing the standard curve of the impurities includes the following steps:

[0043] Prepare standard solutions with concentration gradients by taking the standard of the impurity; detect the standard solutions of the impurity using the high performance liquid chromatography method as described above, and use the peak area as the ordinate and the concentration of the standard solution of the impurity as the abscissa to obtain the result.

[0044] Even better, when preparing standard solutions with concentration gradients, the solvent used is water, for example, deionized water.

[0045] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.

[0046] The reagents and raw materials used in this invention are all commercially available.

[0047] The positive and progressive effects of this invention are as follows:

[0048] The pretreatment method for detecting impurities in carboxymaltose iron products provided by this invention can effectively remove carboxymaltose iron products by ultrafiltration, preventing damage to the chromatographic column and matrix interference during the detection of impurities.

[0049] The method for detecting impurities in carboxymaltose iron products provided by this invention can accurately determine impurities in carboxymaltose iron products without being affected by matrix interference. Moreover, the equipment requirements are not high, and the detection can be completed using a common liquid chromatograph with a cost-effective chromatographic column. In addition, the glucose and fructose main peaks obtained by this detection method have good peak shape symmetry, resolution, stability and content accuracy, and can simultaneously determine the content of glucose and fructose. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the structure of carboxymaltose iron in the background art.

[0051] Figure 2 This is a high-performance liquid chromatography (HPLC) overlay of the reference solution, test solution, spiked test solution, and blank solution from Example 1.

[0052] Figure 3 This is a high-performance liquid chromatography (HPLC) overlay of the reference solution, test solution, and blank solution in Comparative Example 1.

[0053] Figure 4 This is a high-performance liquid chromatography (HPLC) overlay of the reference solution, the test solution, and the spiked test solution in Comparative Example 2.

[0054] Figure 5 This is a high-performance liquid chromatography (HPLC) overlay of the reference solution, test solution, and blank solution in Comparative Example 3. Detailed Implementation

[0055] The present invention is further illustrated below by way of embodiments, but the invention is not limited to the scope of the embodiments described herein. Experimental methods in the following embodiments that do not specify specific conditions were performed according to conventional methods and conditions, or as selected according to the product instructions.

[0056] The carboxymaltose iron products used in the embodiments and comparative examples of this invention are all carboxymaltose iron raw materials, with the following specifications: iron content of 24%-32%, dextrin content of 25%-50%, glucose content ≤0.5%, fructose content ≤0.5%, and other impurities (one or more of glycolic acid, formic acid, acetic acid, lactic acid, malonic acid, pyruvic acid, 2-furanoic acid, 5-hydroxymethyl-2-furanoic acid, 2-furanoic acid, 5-hydroxymethylfurfural, and furfural) content of 2.2%-17%; its batch number is NEU1043-B-2401001 (the carboxymaltose iron raw material used in the following embodiments and comparative examples is abbreviated as NEU1043-B), and its manufacturer is Anhui Yunfan Pharmaceutical Co., Ltd.

[0057] The water used in the embodiments and comparative examples of this invention is deionized water.

[0058] In the embodiments and comparative examples of this invention, the blank solution used was deionized water.

[0059] Example 1

[0060] The ultrafiltration centrifuge tubes used in this embodiment are manufactured by Merck Millipore, model UFC503008 (Amicon Ultra-0.5 centrifugal filter equipped with Ultracel-30 filter membrane). The ultrafiltration membrane of the ultrafiltration centrifuge tube is made of regenerated cellulose membrane with a pore size of 30kDa MWCO.

[0061] Reference solution: Accurately weigh approximately 800 mg each of glucose and fructose reference standards, place them in a 100 mL volumetric flask, add an appropriate amount of water to dissolve, then dilute with water to the mark, and shake well. This is used as a reference stock solution. Accurately measure 5 mL of the reference stock solution and place it in a 50 mL volumetric flask, dilute with water to the mark, and shake well to obtain the reference solution. Accurately inject 15 μL into the liquid chromatograph.

[0062] Test solution: Accurately weigh approximately 1600 mg of NEU1043-B and place it in a 10 mL volumetric flask. Add an appropriate amount of water to dissolve it, then dilute with water to the mark. Shake well. Transfer an appropriate amount of the above solution to an ultrafiltration centrifuge tube and centrifuge at 10000 rpm for 10 min. Collect the filtrate, which is the carboxymaltose iron test solution. Accurately inject 15 μL into the liquid chromatograph.

[0063] Spiked test solution: Accurately weigh approximately 1600 mg of NEU1043-B and place it in a 10 mL volumetric flask. Accurately transfer 1 mL of the reference stock solution to the volumetric flask, dilute to the mark with water, and mix well. Transfer an appropriate amount of the above solution to an ultrafiltration centrifuge tube and centrifuge at 10000 rpm for 10 min. Collect the filtrate. Accurately inject 15 μL into the liquid chromatograph.

[0064] The above-obtained reference solution, test solution, spiked test solution, and blank solution were eluted under the following chromatographic conditions:

[0065] Instrument: Thermo Ultimate 3000

[0066] Column: Waters XBridge BEH Amide 4.6*250mm, 5μm;

[0067] The mobile phase was acetonitrile-water-triethylamine (volume ratio 750:250:2);

[0068] Detector: Differential refractive index detector

[0069] Column temperature: 35℃;

[0070] Detector stability: 35℃;

[0071] Isocratic elution was performed at a flow rate of 1.0 mL / min.

[0072] The detection limit for glucose and fructose using the above method is 0.12 g / L.

[0073] The high-performance liquid chromatography (HPLC) overlays of the reference solution, test solution, spiked test solution, and blank solution in Example 1 are shown below. Figure 2 As shown.

[0074] Depend on Figure 2 The overlay plot of the reference solution shows that the retention time of fructose in the reference solution is 6.942 min and the retention time of glucose is 8.092 min. The separation between each impurity (glucose and fructose) meets the requirements (≥1.5), and the peak shapes are good.

[0075] Depend on Figure 2 The overlay plot of the spiked test solution shows that the retention time of fructose in the spiked test solution is 6.942 min, and the retention time of glucose is 8.075 min. The separation between the impurities meets the requirements (≥1.5), and the peak shapes are good.

[0076] Depend on Figure 2 The overlay chromatogram of the test solution shows that no glucose or fructose peaks were detected in the test solution, and there was no matrix interference in the detection of glucose and fructose peaks.

[0077] Comparative Example 1

[0078] Preparation of the reference solution: At room temperature, weigh glucose and fructose separately and place them in the same volumetric flask (100 mL). Dilute with water to the mark and shake well to obtain the reference solution. Accurately measure 5 mL of reference stock solution 1 and place it in a 50 mL volumetric flask. Dilute with water to the mark and shake well to obtain the reference solution. Accurately transfer 20 μL and inject it into the liquid chromatograph.

[0079] Preparation of the test solution: At room temperature, accurately weigh approximately 190 mg of carboxymaltose iron raw material and place it in a 20 mL headspace vial. Add 8.5 mL of water and heat in a 70 °C water bath until completely dissolved. Accurately add 3.5 mL of trifluoroacetic acid solution, seal, and heat in an oven at 105 °C for 1.5 hours. After cooling, open the headspace vial and transfer all the solution to a 50 mL beaker. Rinse the headspace vial with approximately 2 mL of sodium hydroxide solution (10 mol / L), transferring the washings to the beaker and adding water. Rinse the headspace vial three times with approximately 6 mL of solution. Transfer the washings to a beaker. Adjust the pH to approximately 2.5 with 10 mol / L sodium hydroxide solution, then adjust the pH to between 5 and 7 with 0.5 mol / L sodium hydroxide solution. Transfer all the solution to a 50 mL volumetric flask, add 10 mL of acetonitrile, rinse the beaker with an appropriate amount of water, and transfer the washings to the volumetric flask as well. Dilute to the mark with water, shake well, and let stand for about 10 minutes to allow a flocculent precipitate to form. Filter the supernatant through a 0.45 μm (Mixed cellulose ethers) microporous filter and collect the filtrate. Accurately inject 20 μL into the liquid chromatograph.

[0080] The above-obtained reference solution, test solution, and blank solution were eluted using the same injection volume and the following chromatographic conditions:

[0081] Instrument: Thermo Ultimate 3000

[0082] Chromatographic column: Altima Amino 4.6*250mm, 5μm;

[0083] The mobile phase was acetonitrile-water (70:30);

[0084] Detector: Differential refractive index detector

[0085] Column temperature: 25℃;

[0086] Detector stability: 30℃;

[0087] Isocratic elution,

[0088] The flow rate was 1.0 mL / min.

[0089] The high-performance liquid chromatography (HPLC) overlay of the reference solution, test solution, and blank solution in Comparative Example 1 is shown below. Figure 3 As shown.

[0090] Depend on Figure 3 The overlay chromatogram of the reference solution shows that, under the existing chromatographic conditions and solution preparation conditions, the retention time of fructose in the reference solution is 6.458 min and the retention time of glucose is 7.008 min (the resolution between each impurity meets the requirements (≥1.5), and the peak shape of each peak is good).

[0091] Depend on Figure 3 The overlay plot of the test solution after pretreatment (acid treatment) shows that the test solution has certain matrix interference, and the retention time of fructose after pretreatment is 6.483 min; the retention time of glucose is 6.992 min. The peak area of ​​glucose in the test solution is much higher than the limit level. It is inferred that the acid pretreatment of the test solution will cause the glycosidic bonds in maltodextrin to break and degrade into glucose and fructose, rather than the original impurities (glucose and fructose) in the test sample.

[0092] Comparative Example 2

[0093] Preparation of the reference solution: At room temperature, weigh approximately 500 mg each of glucose and fructose into the same volumetric flask (100 mL), dissolve in water, and dilute to the mark. Shake well to obtain the reference solution stock solution. Accurately measure 5 mL of the reference solution stock solution into a 50 mL volumetric flask, dilute to the mark with water, and shake well to obtain the reference solution. Accurately inject 20 μL into the liquid chromatograph.

[0094] Preparation of the test solution: Accurately weigh 1000 mg of carboxymaltose iron solid raw material at room temperature, place it in a 10 mL volumetric flask, dissolve it in water, and dilute to the mark. Take the supernatant and filter it through a 0.45 μm (mixed cellulose ethers) microporous filter. Accurately transfer 20 μL of the filtrate into the liquid chromatograph.

[0095] Preparation of the spiked test solution: Accurately weigh 1000 mg of carboxymaltose iron solid raw material at room temperature and place it in a 10 mL volumetric flask. Accurately transfer 1 mL of the reference stock solution, dissolve it in water, and dilute to the mark. Filter the supernatant through a 0.45 μm (mixed cellulose ethers) microporous filter and collect 20 μL of the filtrate.

[0096] The above-obtained reference solution, test solution, and spiked test solution were eluted using the same injection volume and the following chromatographic conditions:

[0097] Instrument: Thermo Ultimate 3000

[0098] Chromatographic column: Altima Amino 4.6*250mm, 5μm;

[0099] The mobile phase was acetonitrile-water (80:20);

[0100] Detector: Differential refractive index detector

[0101] Column temperature: 25℃;

[0102] Detector stability: 30℃;

[0103] Isocratic elution,

[0104] The flow rate was 1.0 mL / min.

[0105] The high-performance liquid chromatography (HPLC) overlays of the reference solution, test solution, and spiked test solution in Comparative Example 2 are shown below. Figure 4 As shown.

[0106] Depend on Figure 4 The overlay chromatogram of the reference solution shows that, under the existing chromatographic conditions and solution preparation conditions, the retention time of fructose in the reference solution is 8.950 min, the retention time of glucose is 11.775 min, the resolution between each impurity (glucose and fructose) meets the requirements (≥1.5), and the peak shapes are good.

[0107] Depend on Figure 4 The overlay image of the test solution shows that glucose and fructose were not detected in the test solution.

[0108] Depend on Figure 4 The overlay chromatograms of the spiked test solution show that no glucose or fructose peaks were detected. This suggests that carboxymaltose iron, being a high-molecular-weight complex, encapsulates glucose and fructose in the dextrin, which acts as a sugar ligand, thus interfering with the effective detection of these sugars.

[0109] Comparative Example 3

[0110] The ultrafiltration centrifuge tubes used in this comparative example are manufactured by Merck Millipore, model UFC503008 (Amicon Ultra-0.5 centrifugal filter equipped with Ultracel-30 filter membrane). The ultrafiltration membrane of the ultrafiltration centrifuge tube is made of regenerated cellulose membrane with a pore size of 30 kDa MWCO.

[0111] Preparation of reference solutions: Accurately weigh approximately 50 mg each of glucose and fructose reference standards, and place them in 100 mL volumetric flasks. Dilute to the mark with water and mix well. Accurately inject 20 μL into the liquid chromatograph.

[0112] Preparation of the test solution: Weigh approximately 1000 mg of NEU1043-B accurately, place it in 10 mL of water and add an appropriate amount to dissolve it. Dilute with water to the mark, shake well, transfer an appropriate amount of the above solution to an ultrafiltration centrifuge tube, centrifuge at 10000 rpm for 10 min, and collect the filtrate. Accurately transfer 20 μL and inject it into the liquid chromatograph.

[0113] The above-obtained reference solution, test solution, and blank solution were eluted using the same injection volume and the following chromatographic conditions:

[0114] Instrument: Thermo Ultimate 3000

[0115] Column: Waters XBridge BEH Amide 4.6*250mm, 5μm;

[0116] The mobile phase was acetonitrile-water-ammonia (750:250:1);

[0117] Detector: Differential refractive index detector

[0118] Column temperature: 35℃;

[0119] Detector stability: 35℃;

[0120] Isocratic elution,

[0121] The flow rate was 1.0 mL / min.

[0122] The high-performance liquid chromatography (HPLC) overlay of the reference solution, test solution, and blank solution in Comparative Example 3 is shown below. Figure 5 As shown.

[0123] Depend on Figure 5 As can be seen from the overlay of the reference solution, this method cannot effectively detect glucose and fructose.

Claims

1. A pre-treatment method for detecting impurities in a carboxymaltose iron preparation, characterized by, The carboxymaltose iron product is prepared into a carboxymaltose iron product solution, and the carboxymaltose iron product solution is treated by ultrafiltration centrifugation to retain carboxymaltose iron. The filtrate obtained by ultrafiltration centrifugation is the carboxymaltose iron test solution used for detection; wherein, the impurity is a sugar impurity.

2. The pre-treatment method for detecting impurities in carboxymaltose iron according to claim 1, characterized in that, It meets one or more of the following conditions: (1) The carboxy maltose iron product is carboxy maltose iron raw material or carboxy maltose iron injection; Preferably, the carboxylated maltose iron active pharmaceutical ingredient is a solid, comprising the following components by weight percentage: The iron content is 24%–32%; the maltodextrin content is 25%–50%; the fructose content is ≤0.5%; the glucose content is ≤0.5%; and the content of other impurities is 2.2%–17%, wherein the other impurities are selected from one or more of glycolic acid, formic acid, acetic acid, malonic acid, pyruvic acid, lactic acid, furfural, 5-hydroxymethylfurfural, 2-furanic acid, and 5-hydroxymethyl-2-furanic acid. Preferably, the iron content in the carboxymaltose iron injection is 45-55 mg / mL, for example, 50 mg / mL; (2) The weight-average molecular weight of the carboxylated maltose iron product is 140-210 kDa; (3) When preparing the carboxymaltose iron product solution, the solvent used is water, preferably deionized water; Preferably, when preparing the carboxymaltose iron product solution, the mass-to-volume ratio of the carboxymaltose iron product to the water is 3.8-160 g / L, for example, 0.1 g / L or 0.16 g / L; (4) The sugar impurities are glucose and / or fructose, preferably glucose and fructose.

3. The pre-treatment method for detecting impurities in carboxymaltose iron according to claim 1, characterized in that, The carboxymethyl maltose iron product solution is placed in an ultrafiltration centrifuge tube for ultrafiltration centrifugation, and one or more of the following conditions are met: (1) The tube body of the ultrafiltration centrifuge tube is made of polypropylene and / or styrene-butadiene. Preferably, the ultrafiltration centrifuge tube is an ultrafiltration centrifuge tube of model UFC503008 manufactured by Merck Millipore. More preferably, the ultrafiltration centrifuge tube is an Amicon Ultra-0.5 centrifuge filter equipped with an Ultracel-30 filter membrane. (2) The ultrafiltration membrane of the ultrafiltration centrifuge tube is made of regenerated cellulose membrane; (3) The pore size of the ultrafiltration membrane in the ultrafiltration centrifuge tube is not greater than 70 kDa MWCO, preferably not greater than 46 kDa MWCO, and more preferably, the pore size is 25-35 kDa MWCO, for example 30 kDa MWCO; (4) The rotation speed of the ultrafiltration centrifuge tube during centrifugation is 3000-12000 rpm, for example, 6000 rpm, 8000 rpm or 10000 rpm; (5) The centrifugation time of the ultrafiltration centrifuge tube is 5-20 min, for example, 5 min or 10 min; (6) After ultrafiltration and centrifugation, the filtrate is used as the test solution of carboxymaltose iron.

4. A method for detecting impurities in a carboxymaltose iron preparation, characterized by, It includes the following steps: S1. The carboxymethyl maltose iron test solution as described in any one of claims 1-3 is detected by high performance liquid chromatography (HPLC) to obtain the peak area corresponding to each impurity; the mobile phase of the HPLC is an acetonitrile-water-triethylamine system. S2. Based on the peak areas corresponding to each impurity obtained in S1, the content of impurities in the carboxymaltose iron product is calculated using the external standard method.

5. The method for detecting impurities in a carboxymaltose iron preparation according to claim 4, characterized by, It meets one or more of the following conditions: (1) The chromatographic column of the high performance liquid chromatography method is an aminosilane bonded silica column; the model of the chromatographic column of the high performance liquid chromatography method is, for example, Waters XBridge BEH Amide or Altima Amino; (2) The length of the chromatographic column in the high performance liquid chromatography method is 150-250 mm, for example, 250 mm; (3) The inner diameter of the chromatographic column in the high performance liquid chromatography method is 3.5-4.6 mm, for example 4.6 mm; (4) The particle size of the packing material in the chromatographic column of the high performance liquid chromatography method is 3.5-5μm, such as 5μm; Preferably, the chromatographic column of the high performance liquid chromatography method has a length of 250 mm and an inner diameter of 4.6 mm, and the particle size of the packing material in the chromatographic column is 5 μm.

6. The method for detecting impurities in a carboxymaltose iron preparation according to claim 4, characterized by, The detector used in the high-performance liquid chromatography method is a differential refractive index detector; Preferably, in the high performance liquid chromatography method, the temperature of the differential refractive index detector is 33-37°C, for example, 35°C.

7. The method for detecting impurities in a carboxymaltose iron preparation according to claim 4, characterized by, It meets one or more of the following conditions: (1) In the mobile phase, the volume ratio of the acetonitrile, the water and the triethylamine is (745-755):(245-255):2, for example, 750:250:2; (2) The elution method of the high performance liquid chromatography is isocratic elution; (3) In the high performance liquid chromatography method, the flow rate of the mobile phase is 0.9-1.1 mL / min, for example, 1.0 mL / min; (4) In the high performance liquid chromatography method, the injection volume of the carboxymaltose iron test solution is 5-100 μL, for example 15 μL.

8. The method for detecting impurities in a carboxymaltose iron preparation according to claim 4, characterized by, The temperature of the chromatographic column in the high-performance liquid chromatography method is 33-37℃, for example, 35℃.

9. The method for detecting impurities in a carboxymaltose iron preparation according to claim 4, wherein the carboxymaltose iron preparation is carboxymaltose iron (III). In the method for detecting impurities in the carboxymaltose iron product, the impurity is glucose, and the detection limit of glucose is 0.12 g / L. And / or, in the method for detecting impurities in the carboxymaltose iron product, the impurity is fructose, and the detection limit of fructose is 0.12 g / L.

10. The method for detecting impurities in a carboxymaltose iron preparation according to claim 4, characterized by, In step S2, the content of impurities in the carboxymaltose iron product is calculated using the external standard method based on the standard curve of the impurities. Preferably, the method for preparing the standard curve of the impurities includes the following steps: Prepare standard solutions with concentration gradients by taking the standard of the impurity; detect the standard solutions of the impurity using the high performance liquid chromatography method as described in any one of claims 4-9, and use the peak area as the ordinate and the concentration of the standard solution of the impurity as the abscissa to obtain the result; More preferably, when preparing standard solutions with concentration gradients, the solvent used is water, such as deionized water.

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