Detection method of iopromide impurities

Abstract

The present invention provides a detection method for iopromide impurities, belonging to the field of drug quality control. The dimer impurities of iopromide are detected and analyzed by high performance liquid chromatography, and the chromatographic column uses octadecylsilane bonded silica gel as a filler; the mobile phase A is sodium dihydrogen phosphate solution-acetonitrile (95-98:5-2); the mobile phase B is acetonitrile; the iopromide raw material is subjected to gradient elution to detect the dimer impurities (any one or a combination of impurities D, impurity E, and impurity I) in the iopromide raw material. The detection method of the present invention can realize the effective separation of iopromide and dimer impurities, specifically realize the effective detection and separation of impurities D, impurity E and impurity I at one time, improve the quality standard of the determination of iopromide related substances, and can strictly control the quality of dimer impurities in iopromide, further improving the safety and reliability of iopromide.

Description

Technical Field

[0001] The invention relates to a method for detecting iopromide impurities and belongs to the technical field of drug quality control. Background Art

[0002] Iopromide, chemical name N,N ， -Bis(2,3-dihydroxypropyl)-2,4,6-triiodo-5-[(2-methoxy)acetamido]-N-methyl-1,3-benzenedicarbamide is a non-ionic contrast agent first developed by Schering in Germany. It is widely used in clinical imaging diagnosis of various organs because of its superior imaging effect and significant safety.

[0003] Patent US4364921 reports a method for preparing iopromide, which specifically uses 5-amino-2,4,6-triiodoisophthaloyl chloride as a raw material, and then condenses with 3-amino-1,2-propanediol and 3-methylamino-1,2-propanediol to obtain iopromide after aminoacylation with methoxyacetyl chloride. This method has the advantages of simple process route and mild reaction conditions, but there are highly active acyl chloride structures in the raw materials and intermediates involved in the preparation process. The acyl chloride structure will react with various groups or its own structure to produce impurities that are not the target compound. The preparation route of this method is as follows:

[0004]

[0005] In addition, in order to ensure the safety of medication, each impurity in the active pharmaceutical ingredient must be evaluated for safety, that is, to establish an impurity limit to ensure safety. Both the structure of iopromide itself and the amide structure in the preparation process are active, which makes the impurities of iopromide APIs diverse and poses a major quality risk.

[0006] Although USP43 and EP10.0 disclose 8 organic impurities (A~H) of iopromide and use TLC method to detect and control the content of impurities (A~H), the 8 impurities disclosed are not all the impurities in iopromide. The TLC method cannot quantitatively analyze the target impurities, and the sensitivity and accuracy are poor, which cannot meet the quality control requirements for impurities in iopromide API. At the same time, the presence of dimer impurities in iopromide API increases the difficulty of detecting and separating impurities. The structural formula of organic impurities (A~H) is:

[0007]

[0008] Although there are detection and purification methods for iopromide or iodine contrast agents in the prior art, for example, in CN116106431A, detection and purification are performed by connecting two chromatographic columns in series, the pressure of the chromatographic system is relatively high during the test, and the requirements for the instrument are very high. At the same time, the separation efficiency of the detection method is low, and the impurities (especially dimer impurities) present in the iopromide raw material cannot be effectively separated and detected.

[0009] In view of this, it is indeed necessary to improve the detection method of iopromide impurities to solve the above problems. Summary of the invention

[0010] The object of the present invention is to provide a method for detecting impurities of iopromide, so as to solve the problem that the prior art is unable to detect and separate multiple impurities in iopromide raw materials and is unable to accurately control the quality requirements of iopromide raw materials.

[0011] To achieve the above object, the present invention provides a method for detecting iopromide impurities, using high performance liquid chromatography to detect and analyze the dimer impurities of iopromide, and the chromatographic conditions are:

[0012] Chromatographic column: Octadecylsilane bonded silica gel is used as filler;

[0013] Mobile phase A: sodium dihydrogen phosphate solution-acetonitrile (95-98:5-2);

[0014] Mobile phase B: acetonitrile;

[0015] The gradient elution program was:

[0016] Time (min) Mobile phase A (%) Mobile phase B (%) 0 95～100 5～0 40 95～100 5～0 80 80～90 20～10 95 20～30 80～70 100 95～100 5～0 110 95～100 5～0 .

[0017] As a further improvement of the present invention, the dimer impurity is any one or a combination of impurities D, E and I, and the structural formulas of the impurities D, E and I are respectively:

[0018]

[0019]

[0020] As a further improvement of the present invention, the gradient elution procedure is preferably:

[0021] Time (min) Mobile phase A (%) Mobile phase B (%) 0 98～100 2～0 40 98～100 2～0 80 83～87 17～13 95 23～27 77～73 100 98～100 2～0 110 98～100 2～0 As a further improvement of the present invention, the gradient elution procedure is more preferably:

[0022]

[0023]

[0024] As a further improvement of the present invention, the concentration of the sodium dihydrogen phosphate solution is 0.01 mol / L and the pH value is 2.5.

[0025] As a further improvement of the present invention, sodium dihydrogen phosphate solution-acetonitrile (97:3).

[0026] As a further improvement of the present invention, the model of the chromatographic column is ChromCore AQ-C18, the specification is 4.6 mm×250 mm, and the particle size of the filler is 5 μm.

[0027] As a further improvement of the present invention, the detection wavelength is 220-260 nm, preferably 242 nm.

[0028] As a further improvement of the present invention, the column temperature of the chromatographic column is 40-65°C, preferably 60°C.

[0029] As a further improvement of the present invention, the flow rate of the mobile phase is 0.5-1.0 ml / min, preferably 0.8 ml / min.

[0030] As a further improvement of the present invention, the injection volume is 5 to 15 μL, preferably 10 μL.

[0031] The invention provides a method for detecting an iopromide impurity. A high performance liquid chromatography method is used to detect and analyze the dimer impurity of iopromide. The model specification of the chromatographic column is ChromCoreAQ-C18, 4.6×250 mm, 5 μm.

[0032] The column temperature was 60°C;

[0033] Mobile phase A: sodium dihydrogen phosphate solution-acetonitrile solution (97:3) with a pH of 2.5;

[0034] Mobile phase B: acetonitrile;

[0035] The detection wavelength is 242nm;

[0036] The flow rate of the mobile phase was 0.8 ml / min;

[0037] The injection volume was 10 μL;

[0038] The gradient elution program was:

[0039] Time (min) Mobile phase A (%) Mobile phase B (%) 0 100 0 40 100 0 80 85 15 95 25 75 100 100 0 110 100 0

[0040] The dimer impurities are impurity D, impurity E and impurity I, and the structural formulas of impurity D, impurity E and impurity I are respectively:

[0041]

[0042]

[0043] The present invention also provides an application of an impurity I in the quality control of an iopromide raw material drug, wherein the impurity I is used as an impurity reference substance in the iopromide raw material drug, and the impurity I is 1,3-di{N-methyl-[5-methoxyacetylamino-2,4,6-triiodo-isophthalic acid-(2,3-dihydroxypropyl)]-diamide}-2-propanol, and has the structural formula:

[0044]

[0045] The present invention also provides a method for preparing impurity I, and the synthetic route comprises:

[0046]

[0047] Wherein, the R group in the compound of formula (IV) is Cl or Br or OH.

[0048] As a further improvement of the present invention, the preparation method comprises: the R group in the compound of formula (IV) is Cl or Br, dissolving the compound of formula (IV) in a reaction solvent, adding an acid binding agent and then dropwise adding a compound of formula (V), reacting at 10 to 60° C. for 12 to 60 hours; after the reaction is completed, adding a poor solvent for crystallization, filtering to obtain a crude product of the compound of formula (I), and purifying and refining the crude product of the compound of formula (I) to obtain the compound of formula (I).

[0049] As a further improvement of the present invention, the preparation method comprises: the R group in the compound of formula (IV) is OH, the compound of formula (IV) is dissolved in a reaction solvent, a catalyst is added and then a compound of formula (V) is added dropwise, and the reaction is carried out at 10 to 60° C. for 12 to 60 hours; after the reaction is completed, a poor solvent is added for crystallization, and a crude product of the compound of formula (I) is obtained after filtering, and the crude product of the compound of formula (I) is post-treated to obtain the compound of formula (I).

[0050] As a further improvement of the present invention, the reaction solvent is one or a combination of DMF, DMAc, acetonitrile, methanol, preferably DMF.

[0051] As a further improvement of the present invention, the mass of the reaction solvent is 1 to 10 times, preferably 2 to 3 times, the mass of the compound of formula (IV).

[0052] As a further improvement of the present invention, the equivalent ratio of the compound of formula (IV) to the compound of formula (V) is 1.0:0.3-2.0, preferably 1:0.5.

[0053] As a further improvement of the present invention, the reaction temperature is preferably 20-30° C., and the reaction time is preferably 24 h.

[0054] As a further improvement of the present invention, the poor solvent is one or a combination of ethyl acetate, dichloromethane, ethanol, acetonitrile, and methyl tert-butyl ether, preferably ethyl acetate.

[0055] As a further improvement of the present invention, the post-treatment method is column chromatography treatment, and the elution condition is a gradient elution of DCM / MEOH=1 / 10→1 / 2.

[0056] As a further improvement of the present invention, the acid binding agent is one or a combination of triethylamine, diisopropylethylamine, pyridine, and 2,6-lutidine, preferably triethylamine.

[0057] As a further improvement of the present invention, the equivalent of the acid binding agent is 1.0 to 3.0, preferably 1.0.

[0058] As a further improvement of the present invention, the catalyst is N,N'-carbonyldiimidazole, N,N'-dicyclohexylcarbodiimide, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, or n-propyl phosphoric anhydride, preferably N,N'-carbonyldiimidazole.

[0059] As a further improvement of the present invention, the equivalent weight of the catalyst is 1.0 to 1.5, preferably 1.1.

[0060] The invention has the beneficial effects that the detection method of iopromide impurities disclosed in the invention can realize the effective separation of iopromide and dimer impurities, specifically realize the effective separation and detection of impurity D, impurity E and impurity I at one time, improve the quality standard of the determination of iopromide-related substances, can strictly control the quality of dimer impurities in iopromide, and further improve the safety and reliability of iopromide.

[0061] The invention also discloses an application of impurity I in quality control of an iopromide raw material and a preparation method of impurity I, which can be used to detect and control the content of impurities generated in the preparation or storage process of iopromide, providing an important reference for iopromide quality research, so that the content of relevant impurities in the iopromide raw material meets the pharmaceutical standard, and reduces the potential hidden dangers of iopromide product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 This is the infrared spectrum of iopromide impurity I.

[0063] Figure 2 This is the H NMR spectrum of iopromide impurity I.

[0064] Figure 3 is the chromatogram of the system suitability solution in Example 5.

[0065] Figure 4 It is the chromatogram of the reference substance solution in Example 5.

[0066] Figure 5 It is the chromatogram of the spiked test solution 1 to 6 in Example 5.

[0067] Figure 6-1 It is the chromatogram of the iopromide bulk drug test product in Example 6.

[0068] Figure 6-2 It is the ordinate magnified chromatogram of the iopromide bulk drug test product in Example 6. DETAILED DESCRIPTION

[0069] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is described in detail below in conjunction with the embodiments. It is necessary to point out that the following embodiments are only used to explain and illustrate the present invention and are not used to limit the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above invention content still belong to the protection scope of the present invention.

[0070] The raw materials and reagents used in the embodiment of the present invention are all commercially available products, and the experimental equipment used are all instruments and equipment commonly used in laboratories. In addition, the impurity I in the iopromide bulk drug is derived from the impurity 1,3-dimethylamino-2-propanol or impurity 1,3-bis(dimethylamino)-2-propanol remaining in 3-methylamino-1,2-propylene glycol, and is condensed with the iopromide intermediate 2 to produce.

[0071] Example 1

[0072] Preparation of 1,3-dimethylaminopropanol (Formula V)

[0073] 1,3-Dichloro-2-propanol (20.00 g, 1.0 eq) and 40% methylamine aqueous solution (361.07 g, 30.0 eq) were added to a 250 ml three-necked flask, and solid NaOH (12.40 g, 2.0 eq) was slowly added during stirring. After the addition, the temperature was raised to 60°C and stirred for 3 hours. The reaction solution was extracted with dichloromethane and separated three times. The dichloromethane was combined and concentrated under reduced pressure to dryness to obtain 15.20 g of compound (V) with a purity of 96.8% and a yield of 83%.

[0074] Example 2

[0075] The R group in formula (IV) is Cl, and the impurity I is prepared

[0076] 150g DMF and compound of formula (IV) (50g, 1.0eq) were added to a 1000ml three-necked flask, and triethylamine (1.43g, 1.0eq) was added after stirring and dissolving, and then the mixed solution of 1,3-dimethylaminopropanol (formula V) (4.10g, 0.5eq) prepared in Example 1 was added dropwise, and the temperature was maintained at 20-30°C and stirred for 24h. 500ml acetonitrile was added to the reaction solution, and solid was precipitated. After stirring for 1h, 32.73g of crude product was obtained by filtration. 10g of the crude product was taken for column chromatography, and DCM / MEOH=1 / 10→1 / 2 gradient elution was selected. The eluate was collected and concentrated to obtain 7.6g of compound of formula I. The purity was 96.01%.

[0077] See also Figure 1 As shown, the infrared spectrum IR (Thermo fishe Nicolet IS5, solid KBr pellet) test data are as follows:

[0078] <![CDATA[Wavenumber (cm -1 )]]> Vibration Type Group 3249 Stretching vibration NH 1628 Stretching vibration C=O 1521 Superposition of bending vibration and stretching vibration NH and CN 1351 In-plane bending vibration NH 1244 Stretching vibration CN

[0079] Mass spectrometry MS test data are: 1488[MH]+, 1490[M+H]+.

[0080] See also Figure 2 As shown, the test data of nuclear magnetic resonance hydrogen spectrum (BrukerAdvance III 400 nuclear magnetic resonance spectrometer) is: 1 H NMR(400MHz, Deuterium Oxide)δ4.61–4.48(m,1H),4.33–4.24(m,3H),4.09–3.96(m,2H),3.88–3.81(m,1 H),3.81–3.73(m,2H),3.70–3.38(m,12H),3.30–3.23(m,2H),3.22–2.83(m,8H).

[0081] Example 3

[0082] The R group in formula (IV) is Br, and the impurity I is prepared

[0083] Add 100g of acetonitrile and compound (IV) (50g, 1.0eq) to a 1000ml three-necked flask, stir and dissolve, add diisopropylethylamine (1.43g, 1.0eq), and then drop into the mixed solution of 1,3-dimethylaminopropanol (formula V) (4.10g, 0.5eq) prepared in Example 1. After dropping, keep the temperature at 20-30°C and stir to react for 36h. Add 500ml of EA to the reaction solution, precipitate solid, stir for 1h and filter to obtain 33.23g of crude product. Take 10g of the crude product for column chromatography, select DCM / MEOH=1 / 10→1 / 2 gradient elution, collect and concentrate the eluate to obtain 7.9g of compound I. Purity 95.71%.

[0084] Example 4

[0085] The R group in formula (IV) is OH, and the impurity I is prepared

[0086] Add 100g methanol and compound of formula (IV) (10g, 1.0eq) to a 1000ml three-necked flask, stir and dissolve, control the temperature at 30-40°C, add CDI (N,N'-carbonyldiimidazole) (2.53g, 1.1eq), and then drop into the mixed solution of 1,3-dimethylaminopropanol (formula V) (1.64g, 1.0eq) prepared in Example 1, keep the temperature at 30-40°C and stir to react for 48h. Add 500ml dichloromethane to the reaction solution, precipitate solid, stir for 1h, filter and elute with cold dichloromethane to obtain 5.42g crude product, column chromatography, select DCM / MEOH=1 / 10→1 / 2 gradient elution to obtain 4.33g compound of formula I. Purity 94.32%.

[0087] Example 5

[0088] Detection methods for impurities D, E and I

[0089] Diluent: acetonitrile-water (5:95).

[0090] Reference substance stock solution: Take about 4.077 mg of impurity D, about 3.952 mg of impurity E, and about 3.989 mg of impurity I, respectively, and place them in different 20 ml volumetric bottles, add diluent to dissolve and dilute to the scale, and shake well. Among them, impurities D (content 94.6%) and E (content 96.7%) are purchased from the market, and impurity I (content 96.01%) is prepared by the method of Example 2, Example 3 or Example 4.

[0091] System suitability solution: Take about 20 mg of iopromide and place it in a 10 ml volumetric flask, add 1.0 ml of impurity D stock solution, 0.5 ml of impurity E stock solution, and 0.5 ml of impurity I stock solution, add diluent to dissolve and dilute to the scale, shake well, that is, every 1 ml of system suitability solution contains about 2 mg of iopromide, about 20 μg of impurity D, about 10 μg of impurity E, and about 10 μg of impurity I.

[0092] Reference solution: Accurately pipette 1.0 ml of impurity D stock solution, 0.5 ml of impurity E stock solution, and 0.5 ml of impurity I stock solution into a 10 ml volumetric flask, add diluent to dilute to the scale, and shake well. That is, each 1 ml of reference solution contains about 20 μg of impurity D, about 10 μg of impurity E, and about 10 μg of impurity I.

[0093] Spiked test solution: Take approximately 20.16 mg, 20.09 mg, 20.37 mg, 20.26 mg, 19.93 mg, and 20.12 mg of iopromide test sample, respectively, weigh accurately, and place in different 10 ml volumetric flasks. Add 1.0 ml of impurity D stock solution, 0.5 ml of impurity E stock solution, and 0.5 ml of impurity I stock solution to each volumetric flask, respectively. Add diluent to dissolve and dilute to the scale, shake well, and obtain 6 portions of spiked test solution.

[0094] The chromatographic conditions are:

[0095] Chromatographic column: ChromCoreAQ-C18, 4.6mm×250mm, 5μm or equivalent;

[0096] Detector: UV detector;

[0097] Detection wavelength: 242nm;

[0098] Flow rate: 0.8ml / min;

[0099] Injection volume: 10 μl;

[0100] Column temperature: 60°C;

[0101] Mobile phase A: 0.01 mol / L sodium dihydrogen phosphate solution (pH adjusted to 2.5 with phosphoric acid)-acetonitrile (97:3);

[0102] Mobile phase B: acetonitrile;

[0103] The gradient elution program was:

[0104] Time (min) Mobile phase A (%) Mobile phase B (%) 0 100 0 40 100 0 80 85 15 95 25 75 100 100 0 110 100 0

[0105] According to the above chromatographic conditions, after the system is balanced, the system suitability solution, reference solution, and spiked test solution are injected separately, and the contents of impurity E, impurity I, and impurity E are calculated by peak area using the external standard method.

[0106] The test pattern of system suitability solution is shown in Figure 3 , the test spectrum of the reference solution is shown in Figure 4 , the test spectrum of the spiked test solution is shown in Figure 5 As shown, the spectrum data and separation data are as follows (the separation of isomers of the same impurity is not required, for example: impurities D1 to D14 are isomers of impurity D, impurities I1 to I8 are isomers of impurity I, and impurities E1 to E5 are isomers of impurity E):

[0107]

[0108]

[0109] From the data, it can be seen that the separation degree between impurity D and iopromide is 43.934, which meets the requirements; the separation degree between impurity I and impurity D is 4.731, which meets the requirements; the separation degree between impurity E and impurity I is 2.841, which meets the requirements. It can be seen that the system applicability of this detection method is good.

[0110] Accuracy test

[0111] The six spiked test solutions were tested respectively, and the chromatographic conditions were the same as above. The test data are shown in Figure 5 As shown, the external standard method was used to calculate the recovery of each impurity in 6 spiked test solutions, and the average value and RSD (relative standard deviation) were calculated.

[0112] The test results are as follows:

[0113]

[0114] It can be seen from the data that the spiked recovery rate of impurity D is between 95.5% and 99.9%, and the RSD of 6 determinations is 2.1%. The spiked recovery rate of impurity I is between 97.8% and 104.0%, and the RSD of 6 determinations is 2.1%. The spiked recovery rate of impurity E is between 94.9% and 95.4%, and the RSD of 6 determinations is 0.22%. The accuracy of this detection method is good.

[0115] Example 6

[0116] According to the preparation method of iopromide in the prior art, iopromide API is prepared using 5-amino-2,4,6-triiodoisophthaloyl chloride as a raw material, and the synthesis route is as follows:

[0117]

[0118] The prepared iopromide bulk drug was tested, and the detection method was as shown in Example 5, and the detection spectrum was as shown in Figure 6-1 , Figure 6-2 As shown in the figure, it can be seen that iopromide has 3 main peaks (stereoisomers of iopromide) with a retention time of about 20 to 24 minutes; impurity D has about 14 peaks with a retention time of about 72 minutes; impurity I has about 8 peaks with a retention time of about 79 minutes; impurity E has about 5 peaks with a retention time of about 83 minutes.

[0119] After calculation, the detection results of impurities D, E and I in the synthesized iopromide raw material are shown in the following table:

[0120] Components Impurity D Impurity E Impurity I content% 0.043％ 0.023％ 0.028％

[0121] In summary, the detection method of iopromide impurities disclosed in the present invention can realize the effective separation of iopromide and dimer impurities, specifically realize the effective separation and detection of impurities D, impurity E and impurity I at one time, improve the quality standard of iopromide related substance determination, can carry out strict quality control on dimer impurities in iopromide, further improve the safety and reliability of iopromide. Also disclosed is the application of impurity I in the quality control of iopromide bulk drug and the preparation method of impurity I, which can be used for detecting and controlling the content of impurities generated by iopromide during preparation or storage, provides an important reference for iopromide quality research, makes the content of related impurities in iopromide bulk drug meet the pharmaceutical standard, and reduces the potential hidden danger of iopromide product quality.

[0122] The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for detecting iopromide impurities, characterized in that: The dimer impurity of iopromide was detected and analyzed by high performance liquid chromatography, and the chromatographic conditions were: Chromatographic column: Octadecylsilane bonded silica gel is used as filler; Mobile phase A: sodium dihydrogen phosphate solution-acetonitrile (95-98:5-2); Mobile phase B: acetonitrile; The gradient elution program was: 。 2. the detection method of iopromide impurity according to claim 1, is characterized in that: The dimer impurity is any one or a combination of impurities D, E and I, and the structural formulas of the impurities D, E and I are:

3. The method for detecting iopromide impurities according to claim 1, wherein: The gradient elution procedure is: 。 4. The method for detecting iopromide impurities according to claim 1 or 3, wherein: The gradient elution procedure is:

5. The method for detecting iopromide impurities according to claim 1, wherein: The concentration of the sodium dihydrogen phosphate solution is 0.01 mol / L, and the pH is 2.

5.

6. The method for detecting iopromide impurities according to claim 1, wherein: The mobile phase A is sodium dihydrogen phosphate solution-acetonitrile solution (97:3).

7. The method for detecting iopromide impurities according to claim 1, wherein: The model of the chromatographic column is ChromCoreAQ-C18, the specification is 4.6mm×250mm, and the particle size of the filler is 5μm.

8. The method for detecting iopromide impurities according to claim 1, wherein: The column temperature of the chromatographic column is 40-65°C; and / or, the flow rate of the mobile phase is 0.5 to 1.0 ml / min; and / or, the injection volume is 5 to 15 μL; And / or, the detection wavelength is 220nm to 260nm.

9. An application of impurity I in quality control of iopromide bulk drug, characterized in that: Impurity I is used as an impurity reference substance in the iopromide bulk drug, and the structural formula of the impurity I is:

10. A method for preparing impurity I, characterized in that: The synthetic routes include: Wherein, the R group in the compound of formula (IV) is Cl or Br or OH.

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