Method for measuring content of diethylenetriamine pentaacetic acid in lutetium [177Lu] radiopharmaceutical preparation

Abstract

The invention relates to the technical field of medicine detection, and provides a method for determining the content of diethylenetriamine pentaacetic acid in a lutetium [177Lu] radiopharmaceutical preparation, which comprises the following steps: testing by adopting a high performance liquid chromatography-electrospray detector method, taking porous graphite carbon as a filling agent in a chromatographic column, and eluting by adopting a gradient mode, so as to determine the content of the diethylenetriamine pentaacetic acid in the lutetium [177Lu] radiopharmaceutical preparation. The mobile phase A is an aqueous solution of formic acid, trifluoroacetic acid or perfluorovaleric acid, and the mobile phase B is an acetonitrile solution of formic acid, trifluoroacetic acid or perfluorovaleric acid. According to the detection method, the separation degree of the DTPA reaches 1.5 or above, verification is carried out according to the 9101 Analytical Method Verification Guidance Principle of Chinese Pharmacopoeia 2020 edition, and the method has good system applicability, specificity, accuracy, stability and reliability and can be used for measuring and controlling the content of the DTPA.

Description

Technical Field

[0001] The invention relates to the technical field of drug detection, and in particular to a method for determining the content of diethylenetriaminepentaacetic acid in a lutetium [177Lu] radioactive drug preparation. Background Art

[0002] Lutetium 177 During the preparation of Lu-labeled radiopharmaceuticals, metal chelator DTPA is added. As a highly efficient chelator, DTPA can cause the body to excrete trace elements and cause toxic side effects when the dosage is too large, resulting in damage to body functions. In order to ensure the quality and safety of the drug, the content of DTPA in the drug needs to be controlled.

[0003] At present, the main methods for determining DTPA content are: titration, high performance liquid chromatography and UV-visible spectrophotometry, specifically:

[0004] The titration method is to add a certain amount of ammonia-ammonium chloride buffer to the solution to be tested, and then add an appropriate amount of chrome black T indicator, and use zinc titration solution for complexation titration. The reaction is until the solution turns purple-red, which is the titration end point. This method is generally suitable for substances with high content and relatively simple composition, such as the determination of DTPA content in stannous pentetic acid for injection, but the error is large for low-content DTPA determination.

[0005] High performance liquid chromatography (HPLC) is currently the most effective analytical testing method. Its detectors mainly include ultraviolet detectors, fluorescence detectors, electrochemical detectors, evaporative light scattering detectors and differential refractometers. Conventional HPLC uses ultraviolet detectors, which are also the most widely used detectors in liquid chromatography. It analyzes based on the ability of substances to absorb ultraviolet light. DTPA has no ultraviolet absorption, so it needs to be derivatized when measured by conventional HPLC, that is, DTPA is complexed with metal ions to form a stable complex with stable ultraviolet absorption at a specific wavelength.

[0006] The principle of UV-Vis spectrophotometry is consistent with conventional HPLC. Metal ions are added to derivatize DTPA, and then the content is determined using a UV-Vis spectrophotometer. Finally, the DTPA content is calculated using the standard curve method.

[0007] Since HPLC and UV-Vis spectrophotometry require derivatization treatment, they may be interfered by other excipients in the preparation, affecting the stability and accuracy of the measurement results.

[0008] In view of this, the present invention is proposed. Summary of the invention

[0009] The present invention provides a method for determining the content of diethylenetriaminepentaacetic acid in a lutetium [177Lu] radiopharmaceutical preparation, which is used to solve the defects of insufficient stability and accuracy of the measurement results in the determination method in the prior art. A high performance liquid chromatography-electrospray ionization detector method based on CAD is used, and a specific mobile phase, gradient elution degree and chromatographic column are designed in the detection to detect the DTPA content in the lutetium [177Lu] radiopharmaceutical preparation. The detection method has good system applicability, specificity, accuracy, stability and reliability.

[0010] Specifically, the present invention provides a method for determining the content of diethylenetriaminepentaacetic acid in a lutetium [177Lu] radiopharmaceutical preparation, comprising: using a high performance liquid chromatography-electrospray ionization detector method for testing, wherein the chromatographic column uses porous graphite carbon as a filler, and gradient elution is used, the mobile phase A is an aqueous solution of formic acid, trifluoroacetic acid or perfluoropentanoic acid, and the mobile phase B is an acetonitrile solution of formic acid, trifluoroacetic acid or perfluoropentanoic acid, and the gradient elution procedure is as follows:

[0011] Time / min Mobile phase A / % Mobile phase B / % -5 100 0 0 100 0 3 100 0 18 55 45 20 55 45 .

[0012] HPLC is a common analytical detection method in the art, which has good accuracy and stability. However, when using conventional HPLC to detect DTPA, since DTPA has no ultraviolet absorption, the general analytical method can only be determined by derivatization. Therefore, when using conventional HPLC to analyze, DTPA cannot be detected, or although it is detected, there is a large interference, resulting in a large error in the detection result and instability. For this reason, the present invention proposes to use a CAD-based high-performance liquid chromatography-electrospray detector method to detect the DTPA content in lutetium [177Lu] radiopharmaceutical preparations. The electrospray detector (CAD) is an important tool and means with high sensitivity and high accuracy for substances without ultraviolet absorption or weak ultraviolet absorption. Its principle is: the eluent is atomized to form particles, which are dried by an evaporation tube and collided with charged nitrogen, so that the surface of the analyte particles is positively charged, and finally the charge on the surface of the analyte particles is measured by an electrometer. Therefore, in the present invention, when measuring, DTPA does not need to be complexed with metal ions, thereby avoiding the interference of excipients in the preparation on the experimental results. Moreover, after a large number of experiments, it was found that when using high performance liquid chromatography-electrospray ionization detector to detect the DTPA content in lutetium [177Lu] radiopharmaceutical preparations, in order to effectively separate DTPA and highly polar impurities, it is necessary to select a chromatographic column with porous graphite carbon as the filler.

[0013] According to the method for determining the content of diethylenetriaminepentaacetic acid in lutetium [177Lu] radiopharmaceutical preparations provided by the present invention, mobile phase A is an aqueous solution of trifluoroacetic acid, and mobile phase B is an acetonitrile solution of trifluoroacetic acid.

[0014] The present invention also finds that a gradient elution procedure using an aqueous solution of trifluoroacetic acid as mobile phase A and an acetonitrile solution of trifluoroacetic acid as mobile phase B can achieve a better separation effect.

[0015] According to the method for determining the content of diethylenetriaminepentaacetic acid in lutetium [177Lu] radiopharmaceutical preparations provided by the present invention, the mass concentration of trifluoroacetic acid in mobile phase A is 0.1-0.3%, and the mass concentration of trifluoroacetic acid in mobile phase B is 0.1-0.3%.

[0016] According to the method for determining the content of diethylenetriaminepentaacetic acid in lutetium [177Lu] radiopharmaceutical preparations provided by the present invention, the mass concentration of trifluoroacetic acid in mobile phase A is 0.3%, and the mass concentration of trifluoroacetic acid in mobile phase B is 0.3%.

[0017] The concentrations of mobile phase A and mobile phase B have a certain influence on the separation effect of DTPA. When the mass concentration of trifluoroacetic acid in mobile phase A is 0.1-0.3%, and the mass concentration of trifluoroacetic acid in mobile phase B is 0.1-0.3%, it is beneficial to the separation of DTPA. More preferably, the mass concentration of trifluoroacetic acid in mobile phase A is 0.3%, and the mass concentration of trifluoroacetic acid in mobile phase B is 0.3%. At this time, according to the above-mentioned gradient elution procedure, the separation degree is greater than 1.5, and it is beneficial for each peak to tend to be Gaussian distribution, reducing tailing.

[0018] According to the method for determining the content of diethylenetriaminepentaacetic acid in lutetium [177Lu] radiopharmaceutical preparations provided by the present invention, the chromatographic column is obtained by filling 3.0 μm porous graphite carbon into a C18 column.

[0019] DTPA has a strong polarity, and it is difficult to separate DTPA from highly polar impurities using an ordinary C18 column. The porous graphite carbon chromatographic column used in the present invention has excellent retention and separation properties for polar compounds and can provide the high selectivity required for DTPA separation.

[0020] According to the method for determining the content of diethylenetriaminepentaacetic acid in lutetium [177Lu] radiopharmaceutical preparations provided by the present invention, the chromatographic column is Hypercarb, and the specific specifications are 4.6mm×150mm.

[0021] According to the method for determining the content of diethylenetriaminepentaacetic acid in lutetium [177Lu] radiopharmaceutical preparations provided by the present invention, when the high performance liquid chromatography-electrospray ionization detector method is used for testing, the flow rate is 0.60-1.00 mL / min. Studies have shown that controlling the flow rate within this range is conducive to keeping the retention time of the DTPA peak within a suitable range.

[0022] According to the method for determining the content of diethylenetriaminepentaacetic acid in lutetium [177Lu] radiopharmaceutical preparations provided by the present invention, when the high performance liquid chromatography-electrospray ionization detector method is used for testing, the column temperature is 20°C to 40°C.

[0023] According to the method for determining the content of diethylenetriaminepentaacetic acid in lutetium [177Lu] radiopharmaceutical preparations provided by the present invention, when the high performance liquid chromatography-electrospray detector method is used for testing, the CAD atomization temperature is 30°C to 40°C, the CAD acquisition frequency is 2 to 10 Hz; and the CAD filtering time is 2 to 10 s.

[0024] The method for determining the content of diethylenetriaminepentaacetic acid in a lutetium [177Lu] radiopharmaceutical preparation provided by the present invention comprises:

[0025] Prepare blank solution, reference solution and test solution;

[0026] The blank solution is a TFA aqueous solution or water with a mass concentration of 0.3%;

[0027] The reference solution is obtained by dissolving DTPA in water;

[0028] The test solution is a lutetium [177Lu] radiopharmaceutical preparation;

[0029] Inject the blank solution, control solution and test solution into the chromatograph respectively and record the chromatogram; calculate the DTPA content of the test solution by the external standard method according to the peak area in the chromatogram of the test solution.

[0030] The present invention provides a method for determining the content of diethylenetriaminepentaacetic acid in a lutetium [177Lu] radiopharmaceutical preparation. The method uses a CAD-based high-performance liquid chromatography-electrospray detector method, and designs a specific mobile phase, gradient elution degree, and chromatographic column in the detection to detect the DTPA content in the lutetium [177Lu] radiopharmaceutical preparation. In the detection method, the separation degree of DTPA reaches more than 1.5, and is verified in accordance with the Chinese Pharmacopoeia 2020 edition "9101 Analytical Method Validation Guidelines". The method of the present invention has good system applicability, specificity, accuracy, stability, and reliability, and can be used for the determination and quality control of DTPA content. The establishment of this analytical method realizes the accurate detection of the DTPA content in lutetium [177Lu] radiopharmaceutical preparations, which is of great significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 is the chromatogram of the blank solution of Experimental Example 1 of the present invention;

[0033] Figure 2 It is the chromatogram of DTPA reference solution 1 of Experimental Example 1 and Experimental Example 2 of the present invention;

[0034] Figure 3 is the chromatogram of reference solution 1 of Experimental Example 2 of the present invention;

[0035] Figure 4 is the chromatogram of reference solution 2 of Experimental Example 2 of the present invention;

[0036] Figure 5 is the chromatogram of reference solution 3 of Experimental Example 2 of the present invention;

[0037] Figure 6 is the chromatogram of the test solution 1 of Experimental Example 2 of the present invention;

[0038] Figure 7 is the chromatogram of the test solution 2 of Experimental Example 2 of the present invention;

[0039] Figure 8 is the chromatogram of the test solution 3 of Experimental Example 2 of the present invention;

[0040] Fig. 9 is a spectrum of the DTPA curve equation and range in Experimental Example 3 of the present invention;

[0041] Fig.10 It is the chromatogram of Comparative Example 1 of the present invention;

[0042] Fig.11 It is the chromatogram of Comparative Example 2 of the present invention;

[0043] Fig.12 It is the chromatogram of Comparative Example 3 of the present invention;

[0044] Fig.13 It is the chromatogram of Comparative Example 4 of the present invention. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] If no specific technology or conditions are specified in the examples, the technology or conditions described in the literature in this field or the product instructions are used. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased through regular channels. Among them, acetonitrile is chromatographically pure, Chinese medicine, batch number: 20220128; trifluoroacetic acid comes from Aladdin, batch number: I1902130, and water is sterile water for injection (Chinese medicine, batch number: 2202233203).

[0047] Combine the following Figure 1-Figure 13 The present invention describes a method for determining the content of diethylenetriaminepentaacetic acid in lutetium [177Lu] radiopharmaceutical preparations.

[0048] The present invention provides a method for determining the content of diethylenetriaminepentaacetic acid in a lutetium [177Lu] radiopharmaceutical preparation, comprising: using a high performance liquid chromatography-electrospray detector method for testing, such as Thermo Fisher's Ultimate 3000 high performance liquid chromatograph and Corona Veo RS electrospray detector, wherein the chromatographic column uses porous graphite carbon as a filler, and gradient elution is used, the mobile phase A is an aqueous solution of formic acid, trifluoroacetic acid or perfluorovaleric acid, and the mobile phase B is an acetonitrile solution of formic acid, trifluoroacetic acid or perfluorovaleric acid, and the gradient elution procedure is as follows:

[0049]

[0050]

[0051] Preferably, mobile phase A is an aqueous solution of trifluoroacetic acid, and mobile phase B is an acetonitrile solution of trifluoroacetic acid. More preferably, the mass concentration of trifluoroacetic acid in mobile phase A is 0.1-0.3%, and the mass concentration of trifluoroacetic acid in mobile phase B is 0.1-0.3%, and more preferably, the mass concentration of trifluoroacetic acid in mobile phase A is 0.3%, and the mass concentration of trifluoroacetic acid in mobile phase B is 0.3%.

[0052] The chromatographic column is obtained by filling 3.0 μm porous graphite carbon into a C18 column, and the chromatographic column is Hypercarb, and the specific specification is 4.6 mm×150 mm.

[0053] Preferably, when the high performance liquid chromatography-electrospray detector method is used for testing, the flow rate is 0.60-1.00 mL / min, the column temperature is 20°C-40°C, the CAD atomization temperature is 30°C-40°C, the CAD acquisition frequency is 2-10 Hz; and the CAD filtering time is 2-10 s.

[0054] According to the 2020 edition of the Chinese Pharmacopoeia "9101 Analytical Method Validation Guidelines", the method of the present invention was validated for system suitability, specificity, linearity and range, precision, accuracy and durability, as follows:

[0055] (1) System suitability test

[0056] Prepare blank solution, reference solution and test solution;

[0057] The blank solution is a TFA aqueous solution with a mass concentration of 0.3%;

[0058] DTPA reference solution 1 is prepared by first accurately weighing a certain amount of DTPA reference, dissolving it in water and adjusting the volume to obtain a DTPA mother solution with a concentration of 1.0 mg / mL; then accurately measuring a certain amount of 1.0 mg / mL DTPA mother solution, diluting it with water and adjusting the volume to obtain a DTPA reference solution 1 with a concentration of 50.0 μg / mL;

[0059] The test solution is lutetium[ 177 Lu] Oxyoctreotide injection;

[0060] Determination: The chromatographic column used was Hypercarb, 4.6 mm × 150 mm, 3.0 μm, the CAD nebulization temperature was 35°C, the acquisition frequency was 5 Hz, the filtering time was 3.6 s, the flow rate was 0.8 mL / min, the column temperature was 30°C, the mobile phase A was an aqueous solution of TFA with a mass concentration of 0.3%, the mobile phase B was an acetonitrile solution of TFA with a mass concentration of 0.3%, and gradient elution was used, and the gradient elution was as follows:

[0061] Time / min Mobile phase A / % Mobile phase B / % -5 100 0 0 100 0 3 100 0 18 55 45 20 55 45

[0062] Take the above blank solution and 6 portions of DTPA reference solution 1 with a concentration of 50.0 μg / mL, 15 μL each, and inject them into the high performance liquid chromatograph to record the chromatogram. The test results are shown in Table 1, and the chromatogram of the blank solution is shown in Figure 1 , the chromatogram of DTPA reference solution 1 is shown in Figure 2 .

[0063] Table 1

[0064] Serial number Theoretical plate number (n) Retention time (min) Peak area Tailing Factor 1 117826 12.296 1.369 1.68 2 113774 12.295 1.376 1.61 3 121369 12.288 1.404 1.67 4 116312 12.295 1.372 1.60 5 113236 12.288 1.371 1.57 6 111933 12.287 1.377 1.64 RSD(%) / 0.03 0.94 /

[0065] As can be seen from the above table, the theoretical plate numbers of the six DTPA reference solutions 1 are all above 110,000; the RSDs of the peak retention time and peak area are 0.03% and 0.94%, respectively; and the tailing factors are all below 2.0, which meet the requirements. This indicates that the system applicability of the detection method for determining the DTPA content in lutetium [177Lu] radiopharmaceutical preparations by the high performance liquid chromatography-electrospray ionization detector method provided by the present invention is good.

[0066] (2) Exclusivity

[0067] DTPA reference solution 1: Same as in the system suitability test in part (1).

[0068] Reference solution 1: Prepare a reference solution containing the same concentration of gentisic acid as the preparation.

[0069] Reference solution 2: Prepare a reference solution containing the same concentration of vitamin C as the preparation.

[0070] Reference solution 3: Prepare a reference solution containing the same concentration of DOTA-TATE as the preparation.

[0071] Test solution 1: prepare a non-radioactive solution with the same components and concentration as the preparation as test solution 1, wherein the test solution 1 is different from the above test solution (lutetium [ 177 The only difference between lutetium and lutetium is that lutetium is non-radioactive.

[0072] Test solution 2: Take an appropriate amount of DTPA reference solution 1 and mix with equal volumes of test solution 1, and shake well.

[0073] Test solution 3: Prepare a mixed solution containing other excipients at the same concentration as in the drug product.

[0074] Take 15 μL of each solution and inject it into the HPLC (the test conditions are the same as those in the system suitability test in part (1)), and record the chromatogram. The test results are shown in Table 2. The chromatogram of reference solution 1 is shown in Figure 3 The chromatogram of reference solution 2 is shown in Figure 4 The chromatogram of reference solution 3 is shown in Figure 5 , the chromatogram of DTPA reference solution 1 is shown in Figure 2 , the chromatogram of the test solution 1 is shown in Figure 6 , the chromatogram of test solution 2 is shown in Figure 7 The chromatogram of the test solution 3 is shown in Figure 8 .

[0075] Table 2

[0076] Serial number Sample name Is there any interference Retention time (min) Separation 1 Reference solution 1 none / / 2 Reference solution 2 none / / 3 Reference solution 3 none / / 4 DTPA reference solution 1 / 12.393 / 5 Test solution 1 / 12.379 / 6 Test solution 2 / 12.406 5.23 7 Test solution 3 none / /

[0077] It can be seen from the above table that each reference solution and the test solution 3 have no interference with the DTPA ultraviolet peak; the retention time of the main peak in the DTPA reference solution 1 is 12.393 min, the retention time of the main peak in the test solution 1 is 12.379 min, and the retention time of the main peak in the test solution 2 is 12.406 min. The retention times of the main peaks of the two test solutions are consistent with the retention time of the main peak of the DTPA reference solution 1; the separation between the DTPA main peak and the adjacent peaks meets the requirement of ≥1.5, which indicates that the detection method for determining the DTPA content in the lutetium [177Lu] radioactive pharmaceutical preparation by the high performance liquid chromatography-electrospray ionization detector method provided by the present invention has good specificity.

[0078] (3) Linearity and range

[0079] Accurately measure 0.2 mL, 0.5 mL, 1.0 mL, 2.0 mL and 3.0 mL of the 1.0 mg / mL DTPA stock solution in the system suitability test in part (1) into a 10 mL volumetric flask, dilute to the mark with sterile water for injection, and shake well to obtain a series of DTPA linear solutions with concentrations of 20.0 μg / mL, 50.0 μg / mL, 100.0 μg / mL, 200.0 μg / mL and 300.0 μg / mL.

[0080] Take 15 μL of each linear solution obtained above and inject it into the high performance liquid chromatograph (the measurement conditions are the same as those in the system suitability test in part (1)), record the chromatogram, and use the DTPA concentration as the horizontal axis and the peak area as the vertical axis to draw the curve equation. The results are shown in Table 3, and the chromatogram of the DTPA curve and range is shown in Fig. 9 .

[0081] Table 3

[0082] Element Standard curve Linearity and range r DTPA <![CDATA[y=-0.00002x 2 +0.027x+0.0699]]> 20.0~300.0μg / mL 0.9992

[0083] The above data show that the DTPA solution shows a quadratic curve relationship in the concentration range of 20.0 to 300.0 μg / ml, and the curve equation is y = -0.00002x 2 +0.027x+0.0699, correlation coefficient r=0.9992, meeting the requirement of r≥0.990, and the linear relationship between peak area and concentration is good.

[0084] (4) Repeatability and intermediate precision

[0085] Repeatability: Take 6 portions of DTPA reference solution 1 in the system suitability test in part (1), inject them into the HPLC (the measurement conditions are the same as those in the system suitability test in part (1)), and record the chromatogram. The results are shown in Table 4.

[0086] Table 4

[0087]

[0088] Intermediate precision: Another analyst took 6 portions of DTPA reference solution 1 from the system suitability test in part (1) and injected them into the HPLC (the measurement conditions were the same as those in the system suitability test in part (1)) and recorded the chromatograms. The results are shown in Table 5.

[0089] Table 5

[0090]

[0091] From the above repeatability and intermediate precision tests, it can be seen that the RSD of the main peak area is ≤2.0%, indicating that the repeatability and intermediate precision results are good.

[0092] (5) Accuracy

[0093] Test solution 5: Mix 910 μL of test solution 1 (the same as in the system suitability test in part (1)) and 90 μL of 1 mg / mL DTPA stock solution to obtain test solution 5.

[0094] Take 2 portions of the test solution 1 (the same as in the system suitability test in part (1)) and 6 portions of the test solution 5, inject them into the HPLC (the measurement conditions are the same as in the system suitability test in part (1)), and record the chromatograms. The results are shown in Table 6.

[0095] Table 6

[0096]

[0097]

[0098] Conclusion: This method was used to determine the test solution 5 for a total of 6 times, and the recovery rate of DTPA content was between 80% and 115%, which met the requirements and showed that the accuracy results were good.

[0099] (6) Durability

[0100] DTPA reference solution 2 is prepared by first accurately weighing the 1.0 mg / mL DTPA stock solution from the system suitability test in part (1), diluting it with water and making up the volume to obtain a DTPA reference solution 2 with a concentration of 100.0 μg / mL.

[0101] Take several portions of DTPA reference solution 2 and inject them into the liquid chromatograph under various chromatographic conditions (the measurement conditions are the same as those in the system suitability test in part (1)), record the chromatogram, and the results are shown in Table 7.

[0102] Table 7

[0103]

[0104] From the above data, it can be seen that when the column temperature, flow rate, and chromatographic column model are changed, the RSD of the DTPA content is 2.58%, indicating that the method has good durability.

[0105] The other batches of lutetium [ 177 Lu] Oxyoctreotide injection was injected into a high performance liquid chromatograph (the determination conditions were the same as those in the system suitability test in part (1)) for testing, and the DTPA content could be measured, and the recovery rate was between 80% and 115%, which met the requirements, indicating that the accuracy results were good.

[0106] Comparative Example 1

[0107] A detection method, the process is as follows:

[0108] Preparation of test solution: Add a certain amount of trivalent iron ions to the lutetium [177Lu] radiopharmaceutical preparation to complex with DTPA.

[0109] Determination: The determination conditions are basically the same as those in the system suitability test in part (1), except that the chromatographic column and mobile phase are different, specifically:

[0110] The chromatographic columns are Polaris 5C18-A, 4.6×250 mm.

[0111] The mobile phase was 0.05 M sodium acetate-methanol (v:v) = 95:5.

[0112] The prepared test solution was injected into the HPLC and the content of DTPA was determined based on the ultraviolet absorption of the complex. The results showed that DTPA was not effectively separated. Fig.10 .

[0113] Comparative Example 2

[0114] A detection method, the process is the same as that of comparative example 1, except that the mobile phase is 0.01M sodium dihydrogen phosphate-methanol (v:v) = 95:5. The results show that DTPA cannot be effectively separated. Fig.11 .

[0115] Comparative Example 3

[0116] A detection method, the process is the same as that of comparative example 1, except that the chromatographic column is Poroshell120EC C18, 4μm, 4.6×250mm. The results show that DTPA cannot be effectively separated. Fig.12 .

[0117] Comparative Example 4

[0118] A detection method, the process is as follows:

[0119] Prepare the test solution as in the system suitability test in part (1).

[0120] Determination: The determination conditions are basically the same as those in the system suitability test in part (1), except that the elution procedure is different, as follows:

[0121] Time / min Mobile phase A / % Mobile phase B / % -5 100 0 0 100 0 3 100 0 17 20 80 20 20 80

[0122] The results showed that DTPA could not be separated from the impurities. Fig.13 . It shows that when the elution program is not selected properly, it will affect the test results.

[0123] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for determining the content of diethylenetriaminepentaacetic acid in a lutetium [177Lu] radiopharmaceutical preparation, characterized in that: include: The test was conducted by high performance liquid chromatography-electrospray detector method, wherein the chromatographic column used porous graphite carbon as a filler and gradient elution was adopted, the mobile phase A was an aqueous solution of formic acid, trifluoroacetic acid or perfluorovaleric acid, the mobile phase B was an acetonitrile solution of formic acid, trifluoroacetic acid or perfluorovaleric acid, and the gradient elution procedure was as follows: 。 2. The method for determining the content of diethylenetriaminepentaacetic acid in lutetium [177Lu] radiopharmaceutical preparation according to claim 1, characterized in that Mobile phase A was a trifluoroacetic acid solution in water, and mobile phase B was a trifluoroacetic acid solution in acetonitrile.

3. The method for determining the content of diethylenetriaminepentaacetic acid in lutetium [177Lu] radiopharmaceutical preparation according to claim 2, characterized in that: The mass concentration of trifluoroacetic acid in mobile phase A is 0.1-0.3%, and the mass concentration of trifluoroacetic acid in mobile phase B is 0.1-0.3%.

4. The method for determining the content of diethylenetriaminepentaacetic acid in lutetium [177Lu] radiopharmaceutical preparation according to claim 3, characterized in that: The mass concentration of trifluoroacetic acid in mobile phase A is 0.3%, and the mass concentration of trifluoroacetic acid in mobile phase B is 0.3%.

5. The method for determining the content of diethylenetriaminepentaacetic acid in lutetium [177Lu] radiopharmaceutical preparation according to claim 1, characterized in that: The chromatographic column is obtained by packing 3.0 μm porous graphite carbon into a C18 column.

6. The method for determining the content of diethylenetriaminepentaacetic acid in lutetium [177Lu] radiopharmaceutical preparation according to claim 5, characterized in that: The chromatographic column is Hypercarb, and the specific specifications are 4.6mm×150mm.

7. The method for determining the content of diethylenetriaminepentaacetic acid in lutetium [177Lu] radiopharmaceutical preparations according to any one of claims 1 to 6, characterized in that: When the high performance liquid chromatography-electrospray detector method is used for testing, the flow rate is 0.60 to 1.00 mL / min.

8. The method for determining the content of diethylenetriaminepentaacetic acid in lutetium [177Lu] radiopharmaceutical preparations according to any one of claims 1 to 7, characterized in that: When the high performance liquid chromatography-electrospray detector method is used for testing, the column temperature is 20°C to 40°C.

9. The method for determining the content of diethylenetriaminepentaacetic acid in lutetium [177Lu] radiopharmaceutical preparations according to any one of claims 1 to 8, characterized in that: When the high performance liquid chromatography-electrospray detector method is used for testing, the CAD atomization temperature is 30°C to 40°C, the CAD acquisition frequency is 2 to 10 Hz, and the CAD filtering time is 2 to 10 s.

10. The method for determining the content of diethylenetriaminepentaacetic acid in lutetium [177Lu] radiopharmaceutical preparations according to any one of claims 1 to 9, characterized in that: include: Prepare blank solution, reference solution and test solution; The blank solution is a TFA aqueous solution or water with a mass concentration of 0.3%; The reference solution is obtained by dissolving DTPA in water; The test solution is a lutetium [177Lu] radiopharmaceutical preparation; Inject the blank solution, control solution and test solution into the chromatograph respectively and record the chromatogram; calculate the DTPA content of the test solution by the external standard method according to the peak area in the chromatogram of the test solution.

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