COMPOSITION CONTAINING BUFFER

Abstract

Provided is a composition containing a buffer to be used at the time of labeling of a chelated targeting agent with .sup.90Y, .sup.153Sm, .sup.165Dy, .sup.165Er, .sup.166Ho, or .sup.177Lu. At least one kind of buffer selected from the group consisting of benzoic acid, maleic acid, fumaric acid, succinic acid, and salts thereof is incorporated in a composition containing a chelated targeting agent.

Claims

1: A kit, comprising: (a) a chelated targeting agent comprising a conjugate of a group having a DOTA structure and an anti-CDH3 antibody targeting moiety; and (b) at least one buffer selected from the group consisting of benzoic acid, maleic acid, and salts thereof; and (c) an instruction describing preparing a radioactive metal-labeled chelated targeting agent by mixing a mixture of the chelated targeting agent and the buffer with a radioactive metal selected from the group consisting of .sup.90Y, .sup.153Sm, .sup.165Dy, .sup.165Er, .sup.166Ho, and .sup.177Lu.

2: A kit, comprising: (a) a chelated targeting agent comprising a conjugate of a chelate group comprising a DOTA structure and an anti-CDH3 antibody targeting moiety; and (b) at least one compound selected from the group consisting of benzoic acid, maleic acid, a conjugate base of benzoic acid, a conjugate base of maleic acid, a mixture of benzoic acid and a conjugate base of benzoic acid and a mixture of maleic acid and a conjugate base of maleic acid; and (c) an instruction describing preparing a radioactive metal-labeled chelated targeting agent by mixing a mixture of the chelated targeting agent and the compound with a radioactive metal selected from the group consisting of .sup.90Y, .sup.153Sm, .sup.165Dy, .sup.165Er, .sup.166Ho, and .sup.177Lu.

3: A kit, comprising: (a) a chelated targeting agent comprising a conjugate of a chelate group having a DOTA structure and an anti-CDH3 antibody targeting moiety; and (b) at least one buffer selected from the group consisting of benzoic acid, maleic acid, and salts thereof; and (c) a radioactive metal selected from the group consisting of .sup.90Y, .sup.153Sm, .sup.165Dy, .sup.165Er, .sup.166Ho, and .sup.177Lu, wherein the radioactive metal is in a separate vessel from a vessel containing the chelated targeting agent and the buffer.

4: A kit, comprising: (a) a chelated targeting agent comprising a conjugate of a chelate group comprising a DOTA structure and an anti-CDH3 antibody targeting moiety; and (b) at least one compound selected from the group consisting of benzoic acid, maleic acid, a conjugate base of benzoic acid, a conjugate base of maleic acid, a mixture of benzoic acid and a conjugate base of benzoic acid and a mixture of maleic acid and a conjugate base of maleic acid; and (c) a radioactive metal selected from the group consisting of .sup.90Y, .sup.153Sm, .sup.165Dy, .sup.165Er, .sup.166Ho, and .sup.177Lu, wherein the radioactive metal is in a separate vessel from a vessel containing the chelated targeting agent and the compound.

5: The kit of claim 1, wherein the mixture of the chelated targeting agent and the buffer is freeze-dried.

6: The kit of claim 2, wherein the mixture of the chelated targeting agent and the compound is freeze-dried.

7: The kit of claim 3, wherein the chelated targeting agent and the buffer in the vessel are freeze-dried.

8: The kit of claim 4, wherein the chelated targeting agent and the compound in the vessel are freeze-dried.

9: The kit of claim 1, wherein the buffer is selected from the group consisting of benzoic acid and salts thereof.

10: The kit of claim 2, wherein the compound is selected from the group consisting of benzoic acid, a conjugate base of benzoic acid, and a mixture of benzoic acid and a conjugate base of benzoic acid.

11: The kit of claim 3, wherein the buffer is selected from the group consisting of benzoic acid and salts thereof.

12: The kit of claim 4, wherein the compound is selected from the group consisting of benzoic acid, a conjugate base of benzoic acid, and a mixture of benzoic acid and a conjugate base of benzoic acid.

13: The kit of claim 1, wherein the radioactive metal is selected from the group consisting of .sup.90Y and .sup.177Lu.

14: The kit of claim 2, wherein the radioactive metal is selected from the group consisting of .sup.90Y and .sup.177Lu.

15: The kit of claim 3, wherein the radioactive metal is selected from the group consisting of .sup.90Y and .sup.177Lu.

16: The kit of claim 4, wherein the radioactive metal is selected from the group consisting of .sup.90Y and .sup.177Lu.

Description

EXAMPLES

[0073] Next, the present invention is described in further detail byway of Examples, but the present invention is not limited thereto.

1. Evaluation of Buffer

[0074] Tartaric acid, maleic acid, succinic acid, histidine, glutamic acid, benzoic acid, citric acid, 2-morpholinoethanesulfonic acid, and lactic acid were each selected as a buffer, and a buffering capacity and a labeling yield in a labeling reaction of a chelated targeting agent with .sup.90Y were examined. Acetic acid was examined simultaneously as a control.

[0075] A buffer solution was obtained by mixing an aqueous solution containing each of the buffers and an aqueous solution containing a conjugate acid or a conjugate base thereof or mixing the aqueous solution containing each of the buffers and an aqueous solution of hydrochloric acid or sodium hydroxide to adjust a pH of the buffer solution to 5.5.

[0076] DOTA-PPAT-052-28c described in Patent Literature 1 serving as a DOTA-anti-CDH3 antibody was used as a chelated targeting agent. DOTA-PPAT-052-28c was prepared as an antibody buffer solution in which DOTA-PPAT-052-28c was dissolved in the buffer solution at 2.5 mg/mL or 5 mg/mL.

[0077] DOTA-PPAT-052-28c was mixed with a .sup.90YCl.sub.3 solution (0.04 mol/L hydrochloric acid: manufactured by Cisbio Co., Ltd.) in the presence of the buffer to be labeled with .sup.90Y. The labeling yield was confirmed as described below. A labeling reaction liquid was diluted with an aqueous solution containing DTPA having a chelating ability to .sup.90Y, and an aliquot thereof was subjected to spotting on a thin-layer chromatography strip (manufactured by Biodex, Tec-Control Chromatography 150-771) and development with saline. After that, the labeling yield was confirmed with a radiochromanizer (manufactured by raytest, RITA). On the thin-layer chromatography strip, DOTA-PPAT-052-28c labeled with .sup.90Y remained at the origin, and unreacted .sup.90Y formed a complex with DTPA and was developed at the solvent front.

Evaluation of Tartaric Acid, Maleic Acid, and Succinic Acid

[0078] 100 ?L of an antibody buffer solution having a concentration shown in Table 1 and 38 ?L of a .sup.90YCl.sub.3 solution were mixed with each other and subjected to a reaction at 40? C. for 15 minutes. After the reaction, the labeling yield was calculated by thin-layer chromatography. In addition, 1,000 ?L of the buffer solution and 382 ?L of 0.04 mol/L hydrochloric acid were mixed with each other and measured for a pH.

TABLE-US-00001 TABLE 1 Concentration of buffer Buffer solution (mmol/L) Comparative Sodium acetate buffer solution 125 Example 1 Test Example 1 Sodium tartrate buffer solution 125 Test Example 2 Sodium tartrate buffer solution 12.5 Test Example 3 Sodium maleate buffer solution 125 Test Example 4 Sodium maleate buffer solution 12.5 Test Example 5 Sodium succinate buffer solution 125 Test Example 6 Sodium succinate buffer solution 12.5

[0079] The results are shown in Table 2.

[0080] It was revealed that the buffer solutions were each able to exhibit a buffering capacity comparable to that of the sodium acetate buffer solution when having a concentration of 125 mmol/L. However, the sodium tartrate buffer solution had a low labeling yield despite the fact that a pH appropriate for the labeling reaction was achieved. This suggests that tartaric acid disturbs the labeling reaction with .sup.90Y. The sodium maleate buffer solution and the sodium succinate buffer solution were each able to achieve a labeling yield comparable to that of the sodium acetate buffer solution.

TABLE-US-00002 TABLE 2 pH after mixing Labeling yield (%) Comparative Example 1 5.1 99.4 Test Example 1 4.7 1.8 Test Example 2 3.2 1.0 Test Example 3 5.2 97.3 Test Example 4 2.2 0.1 Test Example 5 5.3 95.6 Test Example 6 3.8 80.9

Evaluation of Histidine, Glutamic Acid, Benzoic Acid, and Maleic Acid

[0081] An antibody buffer solution shown in Table 3 and a .sup.90YCl.sub.3 solution were mixed at a ratio of 50:41 and subjected to a reaction at 40? C. for 15 minutes. After the reaction, the labeling yield was calculated by thin-layer chromatography. The antibody buffer solution shown in Table 3 and 0.05 mol/L hydrochloric acid were mixed at a ratio of 50:41 and measured for a pH.

TABLE-US-00003 TABLE 3 Concentration of buffer Antibody buffer solution (mmol/L) Comparative Sodium acetate buffer solution 250 Example 2 Test Example 7 Histidine buffer solution 200 Test Example 8 Sodium glutamate buffer solution 250 Test Example 9 Sodium benzoate buffer solution 250 Test Example 10 Sodium maleate buffer solution 200

[0082] The results are shown in Table 4.

[0083] It was revealed that the sodium glutamate buffer solution, the sodium benzoate buffer solution, and the sodium maleate buffer solution were each able to exhibit a buffering capacity comparable to that of the sodium acetate buffer solution. However, the sodium glutamate buffer solution had a low labeling yield despite the fact that a pH appropriate for the labeling reaction was achieved. This suggests that glutamic acid disturbs the labeling reaction with .sup.90Y. The sodium benzoate buffer solution and the sodium maleate buffer solution were each able to achieve a labeling yield comparable to that of the sodium acetate buffer solution.

[0084] In addition, it was revealed that the histidine buffer solution did not have a sufficient buffering capacity at a concentration of Test Example 7.

TABLE-US-00004 TABLE 4 pH after mixing Labeling yield (%) Comparative Example 2 4.9 99.5 Test Example 7 1.9 0.1 Test Example 8 4.8 22.2 Test Example 9 4.6 98.8 Test Example 10 5.1 97.1

Evaluation of Citric Acid, 2-Morpholinoethanesulfonic Acid, and Lactic Acid

[0085] An antibody buffer solution shown in Table Sand a .sup.90YCl.sub.3 solution were mixed at a ratio of 50:41 and subjected to a reaction at 40? C. for 20 minutes. After the reaction, the labeling yield was calculated by thin-layer chromatography. The antibody buffer solution shown in Table 5 and 0.05 mol/L hydrochloric acid were mixed at a ratio of 50:41 and measured for a pH.

TABLE-US-00005 TABLE 5 Concentration of buffer Antibody buffer solution (mmol/L) Comparative Sodium acetate buffer solution 250 Example 3 Test Example 11 Sodium citrate buffer solution 250 Test Example 12 2-Morpholinoethanesulfonic acid 250 buffer solution Test Example 13 Lactic acid buffer solution 250

[0086] The results are shown in Table 6.

[0087] It was revealed that the buffer solutions were each able to exhibit a buffering capacity comparable to that of the sodium acetate buffer solution. However, the sodium citrate buffer solution and the lactic acid buffer solution each had a low labeling yield despite the fact that a pH appropriate for the labeling reaction was achieved. This suggests that citric acid and lactic acid each disturb the labeling reaction with .sup.90Y. The 2-morpholinoethanesulfonic acid buffer solution was able to achieve a labeling yield comparable to that of the sodium acetate buffer solution.

TABLE-US-00006 TABLE 6 pH after mixing Labeling yield (% ) Comparative Example 3 99.3 Test Example 11 5.5 0.2 Test Example 12 4.3 99.4 Test Example 13 4.3 4.3

2. Preparation of Freeze-Dried Formulation and Labeling with .SUP.90.Y

[0088] Of the buffers each exhibiting a buffering capacity and a labeling yield comparable to those of the acetate buffer, benzoic acid was selected to prepare a freeze-dried formulation. Moreover, labeling with .sup.90Y was performed through use of the freeze-dried formulation.

[0089] 1.4 mL of a 250 mmol/L sodium benzoate buffer solution containing DOTA-PPAT-052-28c at 5 mg/mL and trehalose at 100 mg/mL was freeze-dried under the conditions shown in Table 7 to yield a freeze-dried formulation in a white cake form.

[0090] Next, labeling with .sup.90Y was performed through use of the freeze-dried formulation. 1.4 mL of water for injection was added to the cake having been generated (Test Example 14). In addition, a 250 mmol/L sodium acetate buffer solution containing DOTA-PPAT-052-28c at 5 mg/mL was used as a control (Comparative Example 4). Each of those antibody solutions and a .sup.90YCl.sub.3 solution were mixed at a ratio of 50:41 and subjected to a reaction at 40? C. for 15 minutes. After the reaction, the labeling yield was calculated by thin-layer chromatography.

TABLE-US-00007 TABLE 7 Temperature (? C.) Time (hour(s):minute(s)) Segment 1 ?40 16:00 Segment 2 ?35 0:40 Segment 3 ?25 0:40 Segment 4 ?10 10:20 Segment 5 0 2:20 Segment 6 10 2:20 Segment 7 20 5:20

[0091] The results are shown in Table 8.

[0092] The 250 mmol/L sodium benzoate buffer solution was able to achieve a labeling yield comparable to that of the sodium acetate buffer solution even when having been freeze-dried. This indicates that the benzoate buffer does not sublimate even through a freeze-drying step and can maintain a sufficient buffering capacity at the time of its use, and is suitable as a buffer for a freeze-dried formulation.

TABLE-US-00008 TABLE 8 Labeling yield (%) Comparative Example 4 98.5 Test Example 14 99.2

INDUSTRIAL APPLICABILITY

[0093] The composition of the present invention is useful for production of a radioactive metal-labeled chelated targeting agent because the buffer contained in the composition can exhibit a pH buffering action without disturbing a reaction between the radioactive metal and the chelated targeting agent.