JP2024043291A - liquid formulation - Google Patents

Abstract

To provide a pharmaceutical with a polysulfide bond.SOLUTION: A liquid formulation comprises a compound represented by a formula (III) or a pharmaceutically acceptable salt or solvate thereof, and at least one ascorbate. (R1-R5: H or an amino acid side chain. R6: an amino group-free amino acid side chain, or the like. R7: a single bond to Q with m=0, or H with m≠0. L: *-NR11-R8-C(=O)-* (R8: a substituted/unsubstituted alkylene or the like. R11: a single bond to Q, or the like. *: a bond). Q: a chelate structure. M: a radioactive/non-radioactive metal nuclide. n: 1-4. m: 0-10).SELECTED DRAWING: Figure 1

Description

The present invention relates to a liquid formulation comprising a specific compound and at least one ascorbate salt. The present invention also relates to a method for improving the stability of the specific compound in a liquid.

A group of compounds with polysulfide bonds have recently attracted attention as "active sulfur molecules." For example, as disclosed in Non-Patent Document 1, it has gradually become clear that this group of compounds plays an important role in redox and signal transduction, which are closely related to in vivo reactive oxygen species and oxidative stress. It is being done.

Furthermore, as disclosed in Non-Patent Document 2, compounds having various polysulfide bonds can be synthesized in the field of organic synthesis or production. Furthermore, as disclosed in Non-Patent Document 3, the size of the ring structure can be easily adjusted, particularly in the cyclization reaction of peptides containing a thiol group.

A new world of active sulfur research, Hide Ihara, Hozumi Motohashi, Takaaki Akaike, Biochemistry, 2019, 91, pp388-398 Rhodium-Catalyzed Synthesis of Organosulfur Compounds Involving S-S Bond Cleavage of Disulfides and Sulfur, Arisawa, M., Yamaguchi, M., Molecules 2020, 25, pp 3595-3630 Synthesis and Pharmacology of Novel Analogues of Oxytocin and Deaminooxytocin: Directed Methods for the Construction of Disulfide and Trisulfide Bridges in Peptides, Chen, L, Zouikova, I, Slaninova, J., Barany,G., J. Med. Chem, 1997, 40, pp 864-876

On the other hand, the application of pharmaceuticals having polysulfide bonds is also being considered, but clinical research has not yet been carried out, and research and development of such pharmaceuticals is desired.

The present invention was made in consideration of the above problems, and aims to realize a pharmaceutical product having a polysulfide bond.

As a result of extensive studies, the present inventors found that compounds having a trisulfide (-SSS-) structure accumulate more in tumors. We also found that compounds with a trisulfide structure have low nonspecific accumulation in the liver and other areas, and are rapidly excreted from the whole body. As a result, it was found that compounds having a trisulfide structure have higher sensitivity for cancer diagnosis, higher therapeutic efficacy, and higher safety than conventional radioactive compounds having a disulfide (-SS-) structure.

Furthermore, the present inventors have demonstrated that by adding at least one ascorbate to the liquid formulation containing the compound having the trisulfide structure, the compound is stable even at room temperature and is also applicable to radiopharmaceuticals. This discovery led to the completion of the present invention.

The liquid formulation according to one aspect of the present invention comprises:
(1) A compound represented by the following formula (III), or a medicamentously acceptable salt or solvate thereof,
(2) at least one ascorbate selected from the group consisting of sodium ascorbate, magnesium ascorbate, aluminum ascorbate, potassium ascorbate, and calcium ascorbate;
A liquid formulation comprising:
(In the formula, R ¹ , R ² , R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom or a side chain of an amino acid, R ⁶ represents an amino acid residue having no amino group, an alkyl group having 1 to 6 carbon atoms and a hydroxyl group, or a hydrogen atom, R ⁷ represents a single bond bonded to Q when m=0, or represents a hydrogen atom when m≠0, and L represents a group represented by the following formula:
* ^-NR11 - ^R8 -C(=O)-*
(In the formula, ^R8 represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene group containing an oxygen atom, or a substituted or unsubstituted alkylene group containing a sulfur atom; ^R11 represents a single bond bonded to Q or a hydrogen atom; and * represents a bond between Q and ^NR7 ( ^R7 represents a hydrogen atom) adjacent to L in the formula (III).
Q represents a chelate structure to which a radioactive or non-radioactive nuclide can be coordinated; M represents a radioactive or non-radioactive metal nuclide, or a radioactive or non-radioactive halogen nuclide; n represents an integer of 1 to 4; and m represents an integer of 0 to 10.

According to one aspect of the present invention, a pharmaceutical product having a polysulfide bond can be provided.

3 is a diagram showing evaluation results of Example 1. FIG. It is a figure which shows the HPLC chart in the absence of sodium ascorbate. It is a figure which shows the HPLC chart in the presence of sodium ascorbate. FIG. 7 is a diagram showing the evaluation results of Example 3.

[Liquid preparation]
The liquid formulation according to one aspect of the present invention is
(1) A compound represented by the following formula (III), or a pharmaceutically acceptable salt or solvate thereof (hereinafter, these may be collectively referred to as the present compound (III)), and
(2) at least one ascorbate;
(In the formula, R ¹ , R ² , R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom or a side chain of an amino acid, and R ⁶ is an amino acid residue without an amino group or a carbon having a hydroxyl group. Represents an alkyl group having 1 to 6 atoms or a hydrogen atom, R ⁷ represents a single bond bonded to Q when m=0, represents a hydrogen atom when m≠0, and L represents the following formula:
*-NR ¹¹ -R ⁸ -C(=O)-*
(In the formula, R ⁸ represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene group containing an oxygen atom, or a substituted or unsubstituted alkylene group containing a sulfur atom, and R ¹¹ is a monomer bonded to Q. (*represents a bond between L and adjacent Q and NR ⁷ (R ⁷ represents a hydrogen atom) in the above formula (III).)
represents a divalent group represented by, Q represents a chelate structure to which a radioactive or non-radioactive nuclide can be coordinated, M represents a radioactive or non-radioactive metal nuclide, or a radioactive or non-radioactive halogen nuclide, n represents an integer from 1 to 4, and m represents an integer from 0 to 10. )

Liquid preparations according to one aspect of the present invention include injections, drips, and the like.

(Present compound (III))
In formula (III), R ² , R ³ , R ⁴ and R ⁵ preferably each independently represent a side chain of an amino acid, more preferably each independently represent a side chain of an amino acid, and R ¹ The amino acid from which ^R2 is derived is the L type, the amino acid from which ^R3 is derived is the D type, the amino acid from which ^R4 is derived is the L type, and the amino acid from which ^R5 is derived is the D type. The amino acid is L-type, and the bond represented by * of the trisulfide methylene group (*-CH ₂ -SSS-) is directly bonded to the carbon atom of formula (III) (i.e., -C ^* Configuration of the substituent of C ^* in H(NH-**)(C(=O)NHCH(R ² )-**) (** independently represents the omission of the preceding group) is preferably L-shaped. In formula (III), R ⁶ preferably represents an amino acid residue having no amino group or an alkyl group having 1 to 6 carbon atoms having a hydroxyl group, more preferably an amino acid residue having no amino group. The configuration of the substituent of the carbon atom (α-carbon atom) that represents a residue or an alkyl group having 1 to 6 carbon atoms and has a hydroxyl group, and to which -C(=O)NH-R ⁶ is directly bonded is: The steric configuration of the substituent of the carbon atom (α-carbon atom) directly bonded to N adjacent to R ⁶ in the above formula in the above R ⁶ is L-type.

In formula (III), the "amino acid side chain" of R ¹ , R ² , R ³ , R ⁴ and R ⁵ is preferably an α-amino acid side chain. In this specification, the "amino acid side chain" refers to the group represented by R when an amino acid (α-amino acid) is represented by the general formula RC(COOH)NH ₂ .

In formula (III), when R ¹ , R ² , R ³ , R ⁴ and R ⁵ are each independently a side chain of an amino acid, preferably R ¹ is a side chain of phenylalanine (Phe) (benzyl group; - CH ₂ C ₆ H ₅ ), R ² is the side chain of tyrosine (Tyr) (p-hydroxyphenylmethyl group), R ³ is the side chain of tryptophan (Trp) (indolylmethyl group), R ⁴ is lysine (Lys ) side chain (4-amino-n-butyl group; -(CH ₂ ) ₄ NH ₂ ), and the side chain where R ⁵ is threonine (Thr) (1-hydroxyethyl group; -CH(OH)CH ₃ ) It is.

In formula (III), the "amino acid residue without an amino group" for R ⁶ is preferably an α-amino acid residue without an amino group, more preferably an amino acid (α-amino acid). is a group represented by -C(COOH)R when represented by the general formula RC(COOH) _NH2 , and more preferably a threonine (Thr) residue (1-carboxy-2-hydroxybutyl group; -C (COOH)CH(OH)CH ₃ ). The threonine residue is also a group corresponding to the above R ⁶ in DOTATATE, an existing SSTR affinity drug.

In formula (III), the "alkyl group having 1 to 6 carbon atoms and having a hydroxyl group" of R ⁶ is preferably an alkyl group having 1 to 6 carbon atoms and having two hydroxyl groups, more preferably an alkyl group having 2 to 6 carbon atoms and having two hydroxyl groups, even more preferably an alkyl group having 3 to 5 carbon atoms and having two hydroxyl groups, still more preferably an alkyl group having 4 carbon atoms and having two hydroxyl groups, and particularly preferably -C(CH ₂ OH)CH(OH)CH _3. The -C(CH ₂ OH)CH(OH)CH ₃ is also a group corresponding to the above R ⁶ in the existing SSTR affinity drugs DOTATOC and DOTANOC.

In formula (III), R ⁶ is preferably an amino acid residue having no amino group, or an alkyl group having 1 to 6 carbon atoms and having a hydroxyl group, and preferred embodiments of each group are as described above. ^{R 6} is more preferably a threonine (Thr) residue, or -C(CH ₂ OH)CH(OH)CH ₃ , even more preferably a threonine (Thr) residue, or -C(CH ₂ OH)CH(OH)CH ₃ , in which the configuration of the substituent of the carbon atom (α-carbon atom) directly bonded to the adjacent N to which these groups are attached is L-type, and even more preferably a threonine (Thr) residue, in which the configuration of the substituent of the α-carbon atom is L-type.

In formula (III), L represents a divalent group represented by the following formula:
*-NR ¹¹ -R ⁸ -C(=O)-*
In the formula, R ⁸ represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene group containing an oxygen atom, or a substituted or unsubstituted alkylene group containing a sulfur atom, and R ¹¹ is a single bond bonded to Q. , or represents a hydrogen atom, and * represents a bond between Q and NR ⁷ (R ⁷ represents a hydrogen atom) adjacent to L in formula (II) and formula (IIa), respectively.

Each carbon atom in the alkylene group, the alkylene group containing an oxygen atom, and the alkylene group containing a sulfur atom in the definition of R ⁸ in the above formula representing L is preferably 1 to 50, more preferably 1 to 50. 40, more preferably 1 to 30, even more preferably 1 to 20, particularly preferably 1 to 10, particularly more preferably 1 to 5. The alkylene group may be linear or branched, but is preferably linear.

The alkylene group containing an oxygen atom and the alkylene group containing a sulfur atom as R ⁸ in the above formula representing L are preferably -(R ¹³ -Z)-(Z represents an oxygen atom or a sulfur atom. ), including repeating units represented by

The above L is preferably a divalent group represented by the following formula (L'):
In the formula, R ¹¹ represents a single bond bonded to Q or a hydrogen atom, R ¹² and R ¹⁴ each independently represent a substituted or unsubstituted alkylene group or a single bond, and p R ¹³ each independently represents a substituted or unsubstituted alkylene group, p Z's each independently represent an oxygen atom or a sulfur atom, and p represents an integer of 0 to 10. However, the total number of carbon atoms of R ¹² , R ¹³ and R ¹⁴ is 1 or more.

As used herein, "substituted or unsubstituted" means that it may or may not have a substituent.

The above R ⁸ is preferably an unsubstituted alkylene group, an unsubstituted alkylene group containing an oxygen atom, or an unsubstituted alkylene group containing a sulfur atom. R ¹² , R ¹³ and R ¹⁴ in the above formula (L') are preferably unsubstituted alkylene groups.

The above -(R ¹³ -Z)- is preferably a group represented by -[(CH ₂ ) _q Z]- (q represents an integer from 1 to 4).

-R ¹² -(R ¹³ -Z) _p -R ¹⁴ - in the above formula (L') is preferably a group represented by the following formula:
-(CH ₂ ) _r1 - [(CH ₂ ) _q Z] _p -(CH ₂ ) _r2 -
In the formula, q represents an integer of 1 to 4, p represents an integer of 1 to 10, r1 and r2 each independently represent an integer of 0 to 10, and p Z's each independently represent an oxygen atom, or Represents a sulfur atom. However, r1+r2+p>1.

q is preferably an integer of 2 to 4, more preferably an integer of 2 to 3. p is preferably an integer of 1 to 5, more preferably an integer of 1 to 2. r1 and r2 are preferably integers of 0 to 5, more preferably integers of 0 to 2, and still more preferably r1 is 0 and r2 is an integer of 0 to 2. Z is preferably an oxygen atom.

Examples of L include the following groups.

In formula (III), m represents an integer from 0 to 10, preferably an integer from 0 to 5, more preferably an integer from 0 to 2, and even more preferably 0.

In formula (III), n represents an integer of 1 to 4, preferably an integer of 1 to 3, more preferably an integer of 1 to 2, and still more preferably 1.

In formula (III), Q represents a chelate structure to which a radioactive or non-radioactive nuclide can be coordinated, preferably a chelate structure having at least one chemical structure selected from the group consisting of Q1 to Q3 below.
Q1: Contains a carboxy group or a nitrogen atom that can coordinate with M (M represents a radioactive or non-radioactive metal nuclide or a radioactive or non-radioactive halogen nuclide).
Q2: M (M represents a radioactive or non-radioactive metal nuclide, or a radioactive or non-radioactive halogen nuclide.) A nitrogen atom to which a coordination site capable of coordinating to M is bonded via a single bond or an alkylene group. have
Q3: It has a hydrocarbon ring containing a hetero atom in the ring constituent atoms and/or a chain hydrocarbon group containing a hetero atom in the main chain, M (M is a radioactive or non-radioactive metal nuclide, or a radioactive or non-radioactive metal nuclide) represents a halogen nuclide) is bonded to at least one of the above heteroatoms via a single bond or an alkylene group.

The number of carboxy groups or nitrogen atoms that can coordinate with M in Q1 as Q in formula (III), and the number of coordination sites that can coordinate with M in Q2 and Q3 are, for example, 1 to 5. and is preferably 2 to 4, more preferably 3 to 4, and still more preferably 3.

The above Q1 is preferably a chelate structure having a carboxy group capable of coordinating with the above M, and the number of the carboxy groups is preferably the above preferred number of coordination sites.

Preferably, the above-mentioned Q2 has a nitrogen atom in which the coordination site capable of coordinating with the above-mentioned M is bonded via an alkylene group, and more preferably, the coordination site capable of coordinating with the above-mentioned M has a carbon atom. It is a chelate structure having nitrogen atoms bonded via an alkylene group having 1 to 2 atoms.

The above Q3 preferably has a hydrocarbon ring containing a hetero atom as a ring member, and a coordination site capable of coordinating with the above M is bonded to at least one of the above hetero atoms via an alkylene group. It has a chelate structure. More preferably, an alkylene having a hydrocarbon ring having 6 to 8 carbon atoms and containing 3 to 4 heteroatoms in the ring constituent atoms, and a coordination position capable of coordinating with the above M having 1 to 2 carbon atoms. It is a chelate structure bonded to at least one of the above heteroatoms via a group. As used herein, "heteroatom" refers to oxygen atom, nitrogen atom, and sulfur atom. The hetero atom in Q3 is preferably an oxygen atom.

Examples of Q include the following structures.

As Q, the above-mentioned DOTA, which has a chelate structure common to existing SSTR affinity drugs DOTATOC, DOTATATE, and DOTANOC, is particularly preferable.

Formula (III) can be represented by the following formula (IIIa), for example, as a preferable steric configuration.
(In the formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , Q, L, M, m, and n, including their definitions and preferred embodiments, represent the formula (III) )

In formula (III) and formula (IIIa), M represents a radioactive or non-radioactive metal nuclide, or a radioactive or non-radioactive halogen nuclide. Radioactive or non-radioactive metal nuclei (radioisotope metal nuclei) include, for example, radioactive or non-radioactive Cu, Ga, Lu, Ac, In, Zr, Y, Sc, Ti, etc., preferably radioactive or non-radioactive Cu, Ga, Lu, Ac, Sc, Ti, more preferably radioactive Cu, Ga, Lu, Ac, Sc, Ti, and even more preferably ⁶⁴ Cu, ⁶⁸ Ga, ¹⁷⁷ Lu, ²²⁵ Ac, ⁴⁴ Sc. Examples of radioactive or non-radioactive halogen nuclides include radioactive F, Cl, Br, I, At, or non-radioactive F, Cl, Br, I, preferably radioactive F, Cl, Br, I, At, more preferably radioactive F, At, and even more preferably ¹⁸ F, ²¹¹ At. M is preferably a radioactive or non-radioactive metal nuclide, more preferably a radioactive metal nuclide, more preferably radioactive Cu, Ga, Lu, Ac, and even more preferably ⁶⁴ Cu, ⁶⁸ Ga, ¹⁷⁷ Lu, ²²⁵ Ac, ⁴⁴ Sc.

As used herein, the term "pharmaceutically acceptable salt" refers to a salt that is not harmful to animal organisms, particularly mammals. Pharmaceutically acceptable salts can be formed with non-toxic acids or bases, including inorganic acids or bases, or organic acids or bases. Pharmaceutically acceptable salts include acid addition salts and base addition salts.

Examples of acidic salts include salts with alkali metals such as sodium, potassium, and lithium; salts with alkaline earth metals such as calcium and magnesium; metal salts such as aluminum and zinc; ammonium salts; and trimethylamine, triethylamine. , tributylamine, pyridine, N,N-dimethylaniline, N-methylpiperidine, N-methylmorpholine, diethylamine, diethanolamine, ethylenediamine, dicyclohexylamine, procaine, chloroprocaine, dibenzylamine, N-benzyl-β-phenethylamine, 1 - Salts of ephenamine and nitrogen-containing organic bases such as N,N'-dibenzylethylenediamine and meglumine (N-methylglucamine); and the like.

Basic salts include, for example, salts with mineral acids such as hydrochloric acid, hydrobromic acid, nitric acid and sulfuric acid; formic acid, acetic acid, citric acid, oxalic acid, fumaric acid, maleic acid, succinic acid, malic acid, tartaric acid. , salts with organic carboxylic acids such as aspartic acid, trichloroacetic acid and trifluoroacetic acid; and salts with sulfonic acids such as methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, mesitylenesulfonic acid and naphthalenesulfonic acid; etc. can be mentioned.

As used herein, "solvate" refers to a solvent-containing compound formed by the association of one or more solvent molecules with a compound according to one embodiment of the present invention. Solvates include, for example, monosolvates, disolvates, trisolvates, and tetrasolvates. Furthermore, solvates include hydrates.

As used herein, "a compound or a pharmaceutically acceptable salt thereof" includes all isomers when there are isomers, and also includes hydrates, solvates, etc. and all crystalline forms. Examples of isomers include optical isomers, geometric isomers, and tautomers.

(ascorbate)
The ascorbates contained in the liquid preparation according to one aspect of the present invention (hereinafter sometimes referred to as "this liquid preparation") include sodium ascorbate, magnesium ascorbate, aluminum ascorbate, potassium ascorbate, and calcium ascorbate. At least one ascorbate selected from the group consisting of:

By containing at least one ascorbate in the present liquid preparation, the present compound (III) exists stably at room temperature. As used herein, "the present compound (III) exists stably" means that the decomposition of the present compound (III) due to cleavage or cleavage of the polysulfide bond of the present compound (III) is suppressed or is difficult to decompose. show. Moreover, in this specification, room temperature indicates 1°C or more and 30°C or less.

The liquid formulation is stable at room temperature for a certain period of time (e.g., 200 hours or less, 150 hours or less, 100 hours or less, etc.), so it is not necessary to use the liquid formulation immediately after preparation. The liquid formulation can be transported (especially at room temperature) after preparation.

The ascorbate salt is preferably sodium ascorbate or potassium ascorbate, and more preferably sodium ascorbate, since the stability of the present compound (III) in the present liquid preparation is higher.

The lower limit of the concentration of the compound (III) in the liquid preparation is preferably 10 pg/mL or more, more preferably 40 pg/mL or more, since the stability of the compound (III) in the liquid preparation is higher. , more preferably 49.4 pg/mL or more. Moreover, the upper limit of the concentration of the present compound (III) in the present liquid preparation is preferably 100 μg/mL or less, more preferably 50 μg/mL or less, and even more preferably 33.4 μg/mL.

The lower limit of the concentration of ascorbate in the liquid preparation is preferably 1.92 mg/mL or more, and more preferably 3 mg/mL or more, since the stability of the compound (III) in the liquid preparation is higher. , more preferably 10 mg/mL or more. Moreover, the upper limit of the concentration of ascorbate in the liquid preparation is preferably 19.2 mg/mL or less, more preferably 18 mg/mL or less, and even more preferably 17 mg/mL or less.

In order to increase the stability of the compound (III) in the liquid formulation, the lower limit of the pH of the liquid formulation is preferably 4.5 or more, more preferably 5.0 or more, and even more preferably 5.3 or more. The upper limit of the pH of the liquid formulation is preferably 7.5 or less, more preferably 6.0 or less, and even more preferably 5.5 or less.

Examples of solvents used in the liquid preparation include buffer solutions such as acetate buffer, citrate buffer, and water. As the buffer solution, an acetate buffer solution is preferred. The concentration of the buffer solution may be, for example, 100 mmol/L or more and 200 mmol/L or less.

(Other ingredients)
In addition to the present compound (III) and ascorbate, the present liquid preparation may contain other components as long as they do not contradict the purpose of the present invention. Examples of other components include diluents, preservatives, pH adjusters, solubilizing agents, and the like.

One embodiment of the present liquid formulation consists of only the present compound (III), ascorbate, and a solvent.

The present liquid formulation contained in a container is also included in one aspect of the present invention. Examples of containers include infusion containers such as pouch containers, syringes such as vials, ampoules, and prefilled syringes.

[Applications of liquid preparations]
This liquid preparation can be preferably used for diagnosis and/or treatment of diseases involving cells expressing somatostatin receptor (SSTR) (especially cells with high expression). Further, it can be preferably used for diagnosis and/or treatment of cancer (tumor), and in particular, it can be preferably used for diagnosis and/or treatment of cancer (tumor) in which SSTR is expressed.

Examples of diseases involving cells that express SSTR (especially cells that express it highly) include arteriosclerosis, cancer (tumor), inflammation, and the like. An embodiment of the present invention also includes a method for diagnosing and/or treating a disease involving cells expressing SSTR by administering the present liquid preparation to a subject.

Typical examples of cancers (tumors) in which SSTR is expressed are tumor-bearing tumors, colon cancer, liver cancer, and neuroendocrine tumors (NET). The target NET to be diagnosed and/or treated with the present liquid preparation is not limited by the tissue in which the NET develops (organ of origin, primary site). NETs occur in various tissues throughout the body, including the gastrointestinal tract, such as the esophagus, stomach, duodenum, small intestine, appendix, and rectum, pancreas, lungs, pituitary gland, uterus, and gallbladder. Examples of target NETs include various NETs such as gastrointestinal endocrine tumors, pancreatic neuroendocrine tumors, and pulmonary neuroendocrine tumors.

The subjects for cancer (tumor) diagnosis and/or treatment using this liquid formulation are humans. For treatment purposes, the subjects are patients with tumors, and for testing or diagnosis purposes, the subjects include healthy individuals, individuals suspected of having cancer, individuals with tumors, and patients undergoing or after tumor treatment.

When M is a radioactive metal nuclide or a halogen nuclide, radioactivity accumulation in the tumor can be increased. Since the radioactivity can treat tumors, the compound can be used for therapeutic purposes. Furthermore, since tumors can be diagnosed by detecting the radioactivity, the compound can be used for diagnostic purposes. In this way, compounds in which M is a radionuclide can be suitably used for both tumor diagnosis and treatment.

Compounds in which M is a non-radioactive metal nuclide or halogen nuclide can be detected accumulated in tumors by nuclear magnetic resonance imaging (MRI). Thereby, the compound can be used for tumor diagnosis.

In view of the above, the liquid formulation may be intended for either the purpose of tumor diagnosis or the purpose of tumor treatment, or for both the purpose of tumor diagnosis and treatment.

One aspect of the present invention includes a method for diagnosing and/or treating cancer (tumor) using the present liquid preparation. The method for diagnosing and/or treating cancer (tumor) includes administering the present liquid preparation to a subject.

The administration route is not particularly limited, and may be selected from common administration routes for liquid preparations, such as parenteral administration, intravenous administration, or intraperitoneal administration.

Explain how to diagnose cancer (tumor). The method for diagnosing cancer (tumor) using the present liquid formulation further includes detecting a compound accumulated in cancer (tumor). The method for detecting the compound is not particularly limited, but when M is a radionuclide, it is preferably detected using a radiation detector that detects radiation emitted from the radionuclide. For example, positron emission tomography (PET) is exemplified as the radiation detector. When M is a non-radioactive metal nuclide or halogen nuclide, it can be detected using MRI as described above.

When using this liquid preparation in a method for diagnosing cancer (tumor), the dose to be administered to the subject may be appropriately determined depending on the detection method for detecting the compound accumulated in cancer (tumor).

The results of detecting compounds accumulated in cancer (tumor) are preferably output as images. In other words, one aspect of the present invention includes a cancer (tumor) imaging method (imaging method) using the present liquid preparation. Further, one embodiment of the present invention includes a cancer (tumor) imaging agent (imaging agent) using the present liquid preparation.

Explain how to treat cancer (tumor). In the method of treating cancer (tumor), it is preferable to use the liquid preparation of the present invention, in which M is a radioactive metal nuclide or a halogen nuclide. When the compound is used for treatment, the compound is administered to the subject in an amount that provides a radioactivity concentration that exhibits a therapeutic effect on the tumor. Generally, in order to achieve sufficient cancer (tumor) treatment effects, it is necessary to set the dose so that the radioactivity concentration is higher than that used for cancer (tumor) diagnosis. preferable.

In this liquid preparation, the lower limit of the single dose of the present compound (III) is preferably 100 pg or more, more preferably 200 pg or more, and even more preferably 247 pg or more per kg of body weight of the subject. Further, the upper limit of the single dose of the present compound (III) is preferably 167 μg or less, more preferably 16.7 μg or less, and even more preferably 5 μg or less.

[Method for producing the present compound (III)]
For example, the present compound (III) can be produced by the following steps:
(1) From two -SR ^p groups possessed by the compound represented by the following formula (IV), or its salt or solvate (hereinafter, these may be collectively referred to as "the present compound (IV)") A compound represented by the following formula (II), or a salt or solvate thereof (hereinafter collectively referred to as "the present compound (II)"), is produced by a trisulfidation step that forms a -S-S-S bond. );
(2) A coordination step in which M (M is the same as M described in formula (III)) or a compound containing this M is acted on the present compound (II) (herein, regarding M, which is a radionuclide, (also referred to as a "labeling step").
(In formulas (II) and (IV), R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , Q, L, m, and n, including their definitions and preferred embodiments) , is the same as formula (III).)

(Step (1))
<Compound (IV)>
In formula (IV), the resin may be, for example, a resin that can be used in solid-phase peptide synthesis. Preferred examples of the resin include 2-chlorotrityl chloride resin (CTC resin), 4-methylbenzhydrylamine hydrochloride resin (MBHA resin), and 4-alkoxybenzyl alcohol resin (Wang resin). In formula (IV), the degree of substitution of the resin is preferably 0.4 to 0.5 mmol/g.

Compound (IV) can be produced from an amino acid and a resin using solid-phase synthesis. The solid-phase synthesis can be carried out by methods well known to those skilled in the art. Examples of solid-phase synthesis include solid-phase synthesis using an Fmoc group (9-fluorenylmethyloxycarbonyl group) or a Boc group (tert-butoxycarbonyl group) as a protecting group for the amino group.

The present compound (IV) (where ^Rp represents a protecting group. Also referred to herein as a "chelate chain peptide resin") can be synthesized from an amino acid and a resin using a solid phase synthesis method. can.

A compound in which R ^p in formula (IV) is a hydrogen atom can be obtained by removing (deprotection) R ^p (i.e., a protecting group) in the chelate chain peptide resin. The method for removing the protecting group of -SH is not particularly limited, but the chelate chain peptide resin may be repeatedly washed with a mixed solution of trifluoroacetic acid (TFA), triisopropylsilane (TIS), and dichloromethane (DCM). When the color of the solution changes from colorless to yellow and then back to colorless, it can be considered that the protecting group of -SH has been removed. The mixed solution preferably has a volume ratio of TFA:TIS:DCM of 2 to 4:4 to 6:90 to 94.

<Trisulfidation step>
In the trisulfidation step in the production of the present compound (II), preferably, two -SR ^p groups (wherein R ^p represents a hydrogen atom) of the compound represented by the above formula (IV) are used as a sulfur source. This includes trisulfidation by cyclization reaction with a compound. Specifically, the two -SR ^p groups (wherein R ^p represents a protecting group) of the compound represented by the above formula (IV) are deprotected to -SH groups, and the sulfur source compound and the ring are deprotected. It is preferable to include trisulfidation by a chemical reaction.

Deprotection of the two -SR ^p groups of the compound represented by formula (IV) (ie, change from R ^p =protecting group to R ^p = hydrogen atom) can be carried out by the method described above. The order in which the deprotection of the -SR ^p group, the removal of the resin in formula (IV), and the trisulfidation are carried out is not particularly limited as long as they can be carried out appropriately. For example, Method 1 and Method 2 below may be mentioned, with Method 1 being preferred.
Method 1:
Method 2: Deprotecting the resin in formula (IV) in a bound state, converting it to trisulfide, and then removing the resin. Method 2:
Method for removing resin in formula (IV), deprotecting, and trisulfidation

An example of each of Method 1 and Method 2 will be described below, including a method for producing the compound represented by formula (IV).
[Method 1]
Step 1A: A compound represented by formula (IV) (chelating linear peptide resin) is produced from an amino acid and a resin by solid phase synthesis.

Step 1B: Remove (deprotect) the -SH protecting group of the compound represented by formula (IV) (R ^p represents a -SH protecting group) obtained in step 1A above, and form a compound represented by formula (IV) ^{The compound represented by ​ ​ ​ ​ ​} ), that is, a chelate chain peptide resin having two -SH groups is obtained.

Step 1C: A cyclization reaction is carried out between the -SH possessed by the compound represented by formula (IV) (R ^p represents -SH) obtained in the above step 1B and a sulfur source compound, and the compound represented by the following formula (V) is The represented compound (chelate cyclic peptide resin) is obtained.
(In the formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , Q, L, m, and n are the same as in formula (IV), including their definitions and preferred embodiments. )

Step 1D: After shrinking the chelate cyclic peptide resin having a trisulfide bond represented by the above formula (V), the cyclic peptide is removed from the resin. After removing the resin by filtration, a compound represented by formula (II) (chelate cyclic peptide or precursor) is obtained from the filtrate.

[Method 2]
Step 2A: A compound represented by formula (IV) (chelate chain peptide resin) is produced from an amino acid and a resin using a solid phase synthesis method.

Step 2B: The polypeptide resin having the compound represented by formula (IV) ( ^Rp represents a protecting group of -SH) obtained in the above step 1A is subjected to a shrinkage treatment. Thereafter, the resin is removed by filtration, and the precipitate is precipitated with ether. The compound represented by the following formula (VI), that is, a compound having two -SH groups (a chelating chain peptide), is obtained.
(In the formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , Q, L, m, and n are the same as those in formula (IV), including their definitions and preferred embodiments.)

Step 2C: A cyclization reaction is performed between the two -SH groups of the compound represented by formula (VI) above and a sulfur source compound, and the compound represented by formula (II) (chelate cyclic peptide or precursor) is obtain.

The following is common to preferred methods for producing the compound represented by formula (IV), including methods 1 and 2 above, centering on trisulfidation.

<Sulfur source compound>
The sulfur source compound used for trisulfidation is preferably the following compound.

The above sulfur source compound can be synthesized as follows. Under anhydrous conditions, indole-1,3-dione and sulfur monochloride (S ₂ Cl ₂ ) are reacted in N,N-dimethylformamide (DMF) for 18-22 hours. The reaction time is preferably at room temperature and the molar ratio of the two raw reagents used, namely indole-1,3-dione:sulfur monochloride, is preferably 1.5 to 2.5:1. be.

<Trisulfidation>
The cyclization reaction between the two -SH groups of the compound represented by formula (IV) (wherein R ^p represents a hydrogen atom) and the sulfur source compound is preferably carried out as follows. The sulfur source compound is dissolved in a solvent, the compound represented by formula (IV) (wherein R ^p represents a hydrogen atom) is added, and the cyclization reaction is carried out with nitrogen or an inert gas. This reaction is then repeated three times, with each reaction time being 1 to 5 hours. The solvent used is a mixed solvent of N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), dichloromethane (DCM), acetonitrile, and methanol, or a single solvent. The reaction is preferably carried out in an aqueous acetonitrile solution for 1 to 5 hours, and in particular, the cyclization reaction in the above-mentioned step 2C is preferably carried out in an aqueous acetonitrile solution for 1 to 5 hours.

The sulfur source compound is preferably used in a molar ratio of 2 to 3 moles per 1 mole of --SH group possessed by the compound represented by formula (IV) (wherein R ^p represents a hydrogen atom).

<Resin removal>
The shrinkage treatment (removal) solvent for the resin used is preferably methanol.

The removal solvent used is also preferably a mixed solution of TFA, TIS and _H2O , a mixed solution of TFA, ethylenediamine (EDT), phenol (PhOH) and _H2O , a mixed solution of TFA, EDT, TIS and PhOH. This is a mixed solution of H 2 O and H ₂ O.

When a mixed solution of TFA, TIS and H ₂ O is used, the volume ratio (TFA:TIS:H ₂ O) is preferably 94-96:2-3:2-3. When a mixed solution of TFA, EDT, PhOH and H ₂ O is used, the volume ratio (TFA:EDT:PhOH:H ₂ O) is preferably 92-98:4-6:2-4:2-13. When a mixed solution of TFA, EDT, TIS, PhOH and H ₂ O is used, the volume ratio (TFA:EDT:TIS:PhOH:H ₂ O) is preferably 76-84:4-6:4-6:4-6:4-6.

The resin removal time is preferably 1 to 3 hours to release the polypeptide from the resin.

<Purification>
The method for purifying the synthesized compound (II) (chelate cyclic peptide or precursor) (for example, purifying the target product from the filtrate in step 1D above) is preferably as follows. Precipitate the filtrate with ether and collect the precipitate. Furthermore, the precipitate is dissolved with acetonitrile and purified by RP-HPLC to obtain a chelate cyclic peptide compound having trisulfide.

(Step (2))
In step (2), a coordination step (herein referred to as a radionuclide) in which M (M is the same as M described in formula (III)) or a compound containing this M is acted on compound (II). The present compound (III) can be produced by a method including (also referred to as a "labeling step" for a certain M).

Examples of M (M is the same as M described in formula (III)) or a compound containing M include metal chloride when M is a radioactive or non-radioactive metal nuclide, and preferably , M ^X Cl _x ( ^M is ⁶⁴ _CuCl2 . Examples of the above M or a compound containing this M include those produced using a cyclotron.

The method of causing the above-mentioned M or a compound containing this M to act on the present compound (II) is not particularly limited. For example, a solution of the present compound (II) (e.g., sodium acetate solution) and a solution (e.g., sodium acetate solution) containing 10 to 20 mCi of the above M or a compound containing the M are mixed, and the mixture is heated at 10 to 90°C (e.g., Examples include a method of reacting at room temperature for 1 minute to 2 hours. The method for producing the present compound (II) is as described above.

Examples of methods for identifying the structures of the present compounds (II) to (IV) include analysis by mass spectrometry, nuclear magnetic resonance (NMR), and the like.

[Method of improving the stability of the present compound (III)]
A step of causing the liquid containing the present compound (III) to contain at least one ascorbate selected from the group consisting of sodium ascorbate, magnesium ascorbate, aluminum ascorbate, potassium ascorbate, and calcium ascorbate, A method for improving the stability of the present compound (III) is also included in one embodiment of the present invention. The solvent used for the liquid can be the same as the solvent used for the liquid formulation. In the step of containing the ascorbate, the present compound (III) may be added to the solvent containing the ascorbate, or the ascorbate may be added to the solvent containing the present compound (III). . Alternatively, the ascorbate may be contained in a liquid containing the present compound (III) by mixing the ascorbate, the present compound (III), and a solvent.

By containing ascorbate in the liquid containing the present compound (III), the decomposition of the present compound (III) is suppressed or difficult to decompose even at room temperature, and the stability of the present compound (III) can be improved. . Therefore, the method of improving the stability of the present compound (III) can also be applied to improving the analysis method of the present compound (III) (for example, direct detection of the present compound (III) by high-sensitivity mass spectrometry).

〔summary〕
The liquid preparation according to aspect 1 of the present invention comprises (1) a compound represented by the following formula (III), or a pharmaceutically acceptable salt or solvate thereof;
(2) Contains at least one ascorbate selected from the group consisting of sodium ascorbate, magnesium ascorbate, aluminum ascorbate, potassium ascorbate, and calcium ascorbate.
(In the formula, R ¹ , R ² , R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom or a side chain of an amino acid, and R ⁶ is an amino acid residue without an amino group or a carbon having a hydroxyl group. Represents an alkyl group having 1 to 6 atoms or a hydrogen atom, R ⁷ represents a single bond bonded to Q when m=0, represents a hydrogen atom when m≠0, and L represents the following formula:
*-NR ¹¹ -R ⁸ -C(=O)-*
(In the formula, R ⁸ represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene group containing an oxygen atom, or a substituted or unsubstituted alkylene group containing a sulfur atom, and R ¹¹ is a monomer bonded to Q. (*represents a bond between L and adjacent Q and NR ⁷ (R ⁷ represents a hydrogen atom) in the above formula (III).)
represents a divalent group represented by, Q represents a chelate structure to which a radioactive or non-radioactive nuclide can be coordinated, M represents a radioactive or non-radioactive metal nuclide, or a radioactive or non-radioactive halogen nuclide, n represents an integer from 1 to 4, and m represents an integer from 0 to 10. )

In the liquid preparation according to Aspect 2 of the present invention, in Aspect 1, Q is a carboxylic acid that can be coordinated with M (M represents a radioactive or non-radioactive metal nuclide, or a radioactive or non-radioactive halogen nuclide). group or has a nitrogen atom.

In the liquid preparation according to aspect 3 of the present invention, in aspect 1 or 2, the above Q is coordinated with M (M represents a radioactive or non-radioactive metal nuclide or a radioactive or non-radioactive halogen nuclide). The resulting coordination site has a nitrogen atom bonded via a single bond or an alkylene group.

In the liquid formulation according to aspect 4 of the present invention, in any one of aspects 1 to 3, Q has a hydrocarbon ring containing a heteroatom as a ring-constituting atom and/or a chain-like hydrocarbon group containing a heteroatom in the main chain, and a coordination site capable of coordinating with M (M represents a radioactive or non-radioactive metal nuclide, or a radioactive or non-radioactive halogen nuclide) is bonded to at least one of the heteroatoms via a single bond or an alkylene group.

In the liquid preparation according to aspect 5 of the present invention, in any one of aspects 1 to 4, the above M is Cu, Ga, Lu, Ac, In, Zr, Y, Sc, Ti, F, Cl, Br, I , and At, and these nuclides are radioactive or non-radioactive.

In the liquid preparation according to Aspect 6 of the present invention, in any of Aspects 1 to 5 above, L is the following formula (L'):
(In the formula, R ¹¹ represents a single bond bonded to Q or a hydrogen atom, R ¹² and R ¹⁴ each independently represent a substituted or unsubstituted alkylene group or a single bond, and p R ¹³ each Each of the p Z's independently represents a substituted or unsubstituted alkylene group, each independently represents an oxygen atom or a sulfur atom, and p represents an integer from 0 to 10.However, R ¹² , R ¹³ and R ¹⁴ The total number of carbon atoms is 1 or more.)
It is a divalent group represented by

A liquid formulation according to Aspect 7 of the present invention is a liquid formulation according to any one of Aspects 1 to 6, wherein R ¹ , R ² , R ³ , R ⁴ and R ⁵ are each independently a side chain of an amino acid, the amino acid from which R ¹ is derived is D-type, the amino acid from which R ² is derived is L-type, the amino acid from which R ³ is derived is D-type, the amino acid from which R ⁴ is derived is L-type, and the amino acid from which R ⁵ is derived is L-type, _the configuration of the substituent at the carbon atom of formula (III) to which the bond represented by * in the trisulfide methylene group (*-CH 2 -S-S-S-) is directly bonded (i.e., C* in -C ^* H(NH-**)(C(═O)NHCH(R ² )-**) ( ^** independently represents an omission of the group preceding it)) is L-type, ⁶ is an amino acid residue having no amino group, or an alkyl group having 1 to 6 carbon atoms having a hydroxyl group, and the configuration of the substituent of the carbon atom (α-carbon atom) to which —C(═O)NH—R ⁶ is directly bonded is L-type.

The liquid formulation according to aspect 8 of the present invention, in any one of aspects 1 to 7 above, has a concentration of the compound represented by formula (III) above or a medicamentously acceptable salt or solvate thereof of 10 ng/mL or more and 100 μg/mL or less.

In the liquid formulation according to aspect 9 of the present invention, in any one of aspects 1 to 8, the concentration of the ascorbate is 1.92 mg/mL or more and 19.2 mg/mL or less.

The liquid preparation according to aspect 10 of the present invention has a pH of 4.5 or more and 7.5 or less in any one of the above aspects 1 to 9.

The liquid preparation according to aspect 11 of the present invention is for diagnosis and/or treatment of a disease associated with cells expressing somatostatin receptor (SSTR) in any one of aspects 1 to 10 above.

A method according to aspect 12 of the present invention includes a liquid containing a compound represented by the following formula (III), or a pharmaceutically acceptable salt or solvate thereof, including sodium ascorbate, magnesium ascorbate, aluminum ascorbate, A compound represented by formula (III) in a liquid, or a pharmaceutically acceptable salt thereof, comprising the step of containing at least one ascorbate selected from the group consisting of potassium ascorbate and calcium ascorbate. This method improves the stability of solvates.
(In the formula, R ¹ , R ² , R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom or a side chain of an amino acid, and R ⁶ is an amino acid residue without an amino group or a carbon having a hydroxyl group. Represents an alkyl group having 1 to 6 atoms or a hydrogen atom, R ⁷ represents a single bond bonded to Q when m=0, represents a hydrogen atom when m≠0, and L represents the following formula:
*-NR ¹¹ -R ⁸ -C(=O)-*
(In the formula, R ⁸ represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene group containing an oxygen atom, or a substituted or unsubstituted alkylene group containing a sulfur atom, and R ¹¹ is a monomer bonded to Q. (*represents a bond between L and adjacent Q and NR ⁷ (R ⁷ represents a hydrogen atom) in the above formula (III).)
represents a divalent group represented by, Q represents a chelate structure to which a radioactive or non-radioactive nuclide can be coordinated, M represents a radioactive or non-radioactive metal nuclide, or a radioactive or non-radioactive halogen nuclide, n represents an integer from 1 to 4, and m represents an integer from 0 to 10. )

EXAMPLES Below, embodiments of the present invention will be described in more detail with reference to Examples. Of course, the present invention is not limited to the following embodiments, and it goes without saying that various modifications can be made to the details. Furthermore, the present invention is not limited to the embodiments described above, and various changes can be made within the scope of the claims, and the present invention also includes embodiments obtained by appropriately combining the disclosed technical means. falls within the technical scope of the invention. Additionally, all documents mentioned herein are incorporated by reference.

[Example 1] Stability test of copper complex cyclic peptide having a polysulfide bond The copper complex cyclic peptide having a polysulfide bond (hereinafter sometimes referred to as "the copper complex cyclic peptide of Example 1") was manufactured by outsourcing. . The structure of the copper complex cyclic peptide of Example 1 is shown below.

200mM acetate buffer was purchased from Nacalai Tesque Co., Ltd. Ascorbic acid and tyrosine as additives were purchased from FUJI Film Wako Reagent Co., Ltd. Sodium ascorbate was purchased from Kanto Kagaku Co., Ltd. Water for injection was used as dilution water and was purchased from Otsuka Pharmaceutical Factory.

The copper complex cyclic peptide of Example 1 was prepared using 10 μL of a 100 ppm (100 μg/mL) solution, 190 μL of 200 mmol/L acetate buffer, 100 μL of water for injection with or without stabilizer, and 700 μL of water for injection in a total of 1 mL. To prepare stabilizer-containing water for injection, 169 mg (95 μmol) of ascorbic acid was dissolved in 1 mL of water for injection. Tyrosine (0.96 mg) was dissolved in 0.3 mL of water for injection. Moreover, 192 mg (96 μmol) and 19.2 mg (9.6 μmol) of sodium ascorbate were each dissolved in 1 mL of water for injection. The copper complex cyclic peptide of Example 1 was measured using HPLC immediately after preparation, 24 hours later, 48 hours later, and 144 hours later at room temperature. The results are shown in Figure 1.

As shown in Figure 1, in the case of no stabilizer, the area value remains almost unchanged until 24 hours, but decreases by 18% after 48 hours, and the copper complex cyclic peptide of Example 1 is not detected after 144 hours. It was confirmed. Ascorbic acid, often used as an antioxidant in liquid formulations, showed a 24% area value decrease after 24 hours. This result confirmed that ascorbic acid does not act as a stabilizer for compounds with polysulfide bonds. It has recently become clear that tyrosine contributes to the stability of compounds with polysulfide bonds, but as a result of the measurement, the area value decreased by 15%. When sodium ascorbate was used, the copper complex cyclic peptide of Example 1 was shown to be stable for 6 days at the same molar amount as ascorbic acid. It was also revealed that even when the amount of sodium ascorbate was 1/10, it was stable for up to 48 hours.

[Example 2] Production and stability test of radioactive copper complex cyclic peptide with polysulfide bond Radioactive copper was produced with reference to Ohya, T., et al, Nucl. Med. Bio, 2016, 43, pp 685-691. It was prepared using Add 500 μL of a 5 μg labeled precursor peptide solution (200 mmol/L acetate buffer, pH 5) to 2 mL of 200 mmol/L acetate buffer (pH 5) containing radioactive copper (copper-64) (radioactivity amount 780 MBq) in a 20 mL glass vial. added. Then, the mixture was covered with an aluminum cap, mixed, and allowed to stand at room temperature for 5 minutes. When no stabilizer was included, 0.5 mL of 200 mmol/L acetate buffer and 12 mL of water for injection were added using a syringe, shaken, and collected through a GV filter. When a stabilizer was included, 0.5 mL of 200 mmol/L acetate buffer, 5 mL of water for injection containing 288 mg (1.45 mmol) of sodium ascorbate, and 7 mL of water for injection were added using a syringe. After shaking and mixing, the mixture was collected through a GV filter. The radiochemical purity of the radiopharmaceutical (radioactive copper complex cyclic peptide having a polysulfide bond) was measured using HPLC. FIG. 2 shows the HPLC measurement results for a radioactive drug that does not contain a stabilizer, and FIG. 3 shows the HPLC measurement results for a radioactive drug that contains a stabilizer. The structure of the radioactive copper complex cyclic peptide produced in Example 2 is shown below.

As shown in FIG. 2, the radioactive drug containing no stabilizer degraded after 24 hours. On the other hand, as shown in FIG. 3, when a stabilizer was included, no decomposition of the radioactive drug occurred even after 24 hours. These results confirmed that sodium ascorbate can be used as a stabilizer for radiopharmaceuticals.

[Example 3] Stability test of radioactive copper complex cyclic peptide having polysulfide bond with high radioactivity except that the radioactivity of copper-64 was changed from 780 MBq to 5550 MBq and 256 mg (1.29 mmol) of sodium ascorbate was used. In the same manner as in Example 2, a radioactive drug (a radioactive copper complex cyclic peptide having a polysulfide bond) was synthesized. The radiochemical purity of the radiopharmaceutical was measured using HPLC. The results are shown in Figure 4.

As shown in FIG. 4, no decomposition of the radioactive drug occurred even after 22 hours.

[Example 4] Sterile production and 3-lot test of radioactive copper complex cyclic peptide having a polysulfide bond A radiopharmaceutical agent (radioactive copper having a polysulfide bond) was prepared in the same manner as in Example 2 using 100 μg of labeled precursor cyclic peptide. A complex cyclic peptide) was synthesized. In the sterile environment, the radioactive drug was injected into a sterile isolator through a GV filter, and after dispensing drugs for quality inspection and storage, the radioactive drug was sealed in a product vial. These operations were performed three times on different days to form a three-lot test. The results are shown in Tables 1 and 2.

As shown in Tables 1 and 2, the manufacturing and quality inspection of the injectable preparation produced in Example 4 confirmed that it complied with the standard values.

[Example 5] Estimated exposure dose test of radioactive copper complex cyclic peptide injection having polysulfide bond Estimated exposure dose test was conducted using the injection prepared in Example 4. The mice used were 28 male and female ddy, 8 weeks old, with an average weight of 37.46 g. An injection (1.38 MBq/0.1 mL) was injected through the tail vein, and the mice were sacrificed after 5, 15, 30, 60, 180, 360, and 1440 minutes, and the amount of radioactivity in each organ was measured. Based on this result, the exposure dose was calculated using OLINDA/EXM software. The results are shown in Table 3. The unit of numerical values in Table 3 is μSv/MBq.

The estimated exposure dose of the radioactive copper complex cyclic peptide injection having a polysulfide bond was approximately 5 mSV, which was confirmed to be almost the same as that of 18F-FDG (8.4 mSV; 444 MBq), a common radiopharmaceutical.

[Example 6] Toxicity test of a copper complex cyclic peptide having a polysulfide bond and its precursor A single intravenous administration of a copper complex cyclic peptide having a polysulfide bond and its precursor, a cyclic peptide having a polysulfide bond, to male and female rats An extended single-dose toxicity study was conducted. The copper complex cyclic peptide of Example 1 was used as the copper complex cyclic peptide having a polysulfide bond. The structure of the copper complex cyclic peptide precursor (labeled precursor) of Example 1 is shown below.

The dose of the copper complex cyclic peptide of Example 1 to the subjects was 17.8 ng to 12 μg per person. Assuming that the standard weight of an adult is 72 kg, the dose per body weight was 247 pg/kg to 167 ng/kg, and based on this, the dose of the copper complex cyclic peptide of Example 1 in the toxicity test was set.

In addition, since the test drug contains more labeled precursor than the copper complex cyclic peptide of Example 1, which is the active ingredient, the labeled precursor was evaluated in the toxicity test together with the copper complex cyclic peptide of Example 1, which is the active ingredient. In order to confirm the safety when the test drug contains the entire amount of labeled precursor as the charge amount, the dosage of the labeled precursor in the toxicity test was set based on 80 μg of labeled precursor per person per dose and 1.11 μg/kg of body weight.

From the above, the high dose was set to 167 μg/kg for the copper complex cyclic peptide of Example 1 and 1110 μg/kg for the labeled precursor so that the amount was 1000 times the standard. The low doses were set at 16.7 μg/kg for the copper complex cyclic peptide of Example 1 and 111 μg/kg for the labeled precursor so that they were 100 times the standard amount.

A high-dose group solution was prepared as the test solution, and a low-dose group solution was prepared by diluting the high-dose group solution with a medium. A high-dose group solution (33.4/222 μg/mL: copper complex cyclic peptide/labeled precursor of Example 1) was prepared, and the low-dose group solution was prepared by diluting it 10-fold. The medium used was a 40 mmol/L acetate buffer solution containing 19.2 mg/mL sodium ascorbate.

Test items included observation of general condition, body weight measurement, hematology test, coagulation system test, blood chemistry test, pathological test, organ weight measurement, and histopathological test. The systems used for data collection were the MiTOX-BOZO system (Version 7.6.1, Mitsui E&S System Giken Co., Ltd.) and the PATHOS5 system (Pathology Operating Systems Ltd.), and the statistical analysis was performed using SAS Release 9.1.3 (SAS Institute Inc.). )It was used.

No deaths were observed, and no changes related to the copper complex cyclic peptide and labeled precursor of Example 1 were observed in the general condition, body weight, hematology tests, coagulation system tests, blood chemistry tests, or autopsy.

At necropsy on the day after administration, high testis weights were observed in males at the high dose of 167/1110 μg/kg. However, since the weight increase was slight and similar changes were not observed at autopsy 14 days after administration, the changes were considered to have little toxicological significance.

It was concluded that the no adverse effect level (NOAEL) of the copper complex cyclic peptide of Example 1 having a polysulfide bond and the labeled precursor under the conditions of Example 6 was 167/1110 μg/kg for both sexes.

[Summary of Examples]
It is known that compounds having polysulfide bonds exist stably in the form of crystals and amorphous solids under a nitrogen stream or at temperatures below 4°C. On the other hand, when a compound group having a polysulfide bond is used as the main component of a solution (particularly an injection), the compound group is extremely unstable.

Possible reasons why compounds with polysulfide bonds are unstable in liquids are as follows:
(1) The hydroxyanion in the aqueous solution performs a nucleophilic reaction on the polysulfide bond and cleaves the bond;
(2) Oxidized by dissolved oxygen in the solution and converted to sulfoxide;
(3) When considering application to radiopharmaceuticals that have polysulfide bonds, the energy generated when the radioactive element decays causes water molecules to become hydroxyl radicals, which cleave the polysulfide bonds.

In this example, it was unexpectedly revealed that compounds having polysulfide bonds can be stably present even at room temperature by adding an ascorbate such as sodium ascorbate to a liquid formulation. It was found that this condition can also be applied to radioactive drugs, and that they can be transported at room temperature after being manufactured in a GMP facility.

In addition, by adding ascorbate salts such as sodium ascorbate to a solution containing a group of compounds with polysulfide bonds, we can improve the analysis method of the group of compounds (for example, directly analyze the group of compounds with polysulfide bonds by high-sensitivity mass spectrometry). We have found that it can also be applied to other applications such as detection.

The present invention can be used, for example, in the diagnosis or treatment of cancer (tumor).

Claims (12)

(1) A compound represented by the following formula (III), or a pharmaceutically acceptable salt or solvate thereof, and
(2) at least one ascorbate selected from the group consisting of sodium ascorbate, magnesium ascorbate, aluminum ascorbate, potassium ascorbate, and calcium ascorbate;
liquid formulations, including;
(In the formula, R ¹ , R ² , R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom or a side chain of an amino acid, and R ⁶ is an amino acid residue without an amino group or a carbon having a hydroxyl group. Represents an alkyl group having 1 to 6 atoms or a hydrogen atom, R ⁷ represents a single bond bonded to Q when m=0, represents a hydrogen atom when m≠0, and L represents the following formula:
*-NR ¹¹ -R ⁸ -C(=O)-*
(In the formula, R ⁸ represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene group containing an oxygen atom, or a substituted or unsubstituted alkylene group containing a sulfur atom, and R ¹¹ is a monomer bonded to Q. (*represents a bond between L and adjacent Q and NR ⁷ (R ⁷ represents a hydrogen atom) in the above formula (III).)
represents a divalent group represented by, Q represents a chelate structure to which a radioactive or non-radioactive nuclide can be coordinated, M represents a radioactive or non-radioactive metal nuclide, or a radioactive or non-radioactive halogen nuclide, n represents an integer from 1 to 4, and m represents an integer from 0 to 10. ) The liquid preparation according to claim 1, wherein the Q has a carboxy group or a nitrogen atom that can coordinate with M (M represents a radioactive or non-radioactive metal nuclide or a radioactive or non-radioactive halogen nuclide). The above Q is nitrogen to which a coordination site capable of coordinating to M (M represents a radioactive or non-radioactive metal nuclide, or a radioactive or non-radioactive halogen nuclide) is bonded via a single bond or an alkylene group. A liquid formulation according to claim 1, having atoms. The liquid formulation according to claim 1, wherein Q has a hydrocarbon ring containing a heteroatom as a ring-constituting atom and/or a chain-like hydrocarbon group containing a heteroatom in the main chain, and a coordination site capable of coordinating with M (M represents a radioactive or non-radioactive metal nuclide, or a radioactive or non-radioactive halogen nuclide) is bonded to at least one of the heteroatoms via a single bond or an alkylene group. The M is at least one selected from the group consisting of Cu, Ga, Lu, Ac, In, Zr, Y, Sc, Ti, F, Cl, Br, I, and At, and these nuclides are radioactive. or non-radioactive, the liquid formulation according to claim 1. The above L is the following formula (L'):
(In the formula, R ¹¹ represents a single bond bonded to Q or a hydrogen atom, R ¹² and R ¹⁴ each independently represent a substituted or unsubstituted alkylene group or a single bond, and p R ¹³ each Each of the p Z's independently represents a substituted or unsubstituted alkylene group, each independently represents an oxygen atom or a sulfur atom, and p represents an integer from 0 to 10.However, R ¹² , R ¹³ and R ¹⁴ The total number of carbon atoms is 1 or more.)
The liquid preparation according to claim 1, which is a divalent group represented by: R ¹ , R ² , R ³ , R ⁴ and R ⁵ are each independently a side chain of an amino acid, the amino acid from which R ¹ is derived is D-type, the amino acid from which R ² is derived is L-type, the amino acid from which R ³ is derived is D-type, the amino acid from which R ⁴ is derived is L-type, the amino acid from which R ⁵ is derived is L-type, _the configuration of the substituent of the carbon atom of formula (III) to which the bond represented by * of the trisulfide methylene group (*-CH 2 -S-S-S-) is directly bonded (i.e., C* in -C ^* H(NH-**)(C ⁽ ═O)NHCH(R ² )-**) (** independently represents the omission of the group preceding it)) is L-type, R ⁶ is an amino acid residue having no amino group or an alkyl group having 1 to 6 carbon atoms and a hydroxyl group, -C(═O)NH-R The liquid formulation according to claim 1, wherein the configuration of the substituent on the carbon atom (α-carbon atom) to which ⁶ is directly bonded is L-type. The liquid formulation according to claim 1, wherein the concentration of the compound represented by formula (III) or a pharma- ceutical acceptable salt or solvate thereof is 10 pg/mL or more and 100 μg/mL or less. The liquid preparation according to claim 8, wherein the concentration of the ascorbate is 1.92 mg/mL or more and 19.2 mg/mL or less. The liquid preparation according to claim 1, having a pH of 4.5 or more and 7.5 or less. Liquid preparation according to any one of claims 1 to 10, which is for the diagnosis and/or treatment of diseases involving cells expressing somatostatin receptors (SSTR). A liquid comprising a compound represented by the following formula (III) or a pharma- ceutical acceptable salt or solvate thereof:
A method for improving the stability of a compound of formula (III), or a pharma- ceutical acceptable salt or solvate thereof in a liquid, comprising the step of incorporating at least one ascorbate selected from the group consisting of sodium ascorbate, magnesium ascorbate, aluminum ascorbate, potassium ascorbate, and calcium ascorbate.
(In the formula, R ¹ , R ² , R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom or a side chain of an amino acid, R ⁶ represents an amino acid residue having no amino group, an alkyl group having 1 to 6 carbon atoms and a hydroxyl group, or a hydrogen atom, R ⁷ represents a single bond bonded to Q when m=0, or represents a hydrogen atom when m≠0, and L represents a group represented by the following formula:
* ^-NR11 - ^R8 -C(=O)-*
(In the formula, ^R8 represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene group containing an oxygen atom, or a substituted or unsubstituted alkylene group containing a sulfur atom; ^R11 represents a single bond bonded to Q or a hydrogen atom; and * represents a bond between Q and ^NR7 ( ^R7 represents a hydrogen atom) adjacent to L in the formula (III).
Q represents a chelate structure to which a radioactive or non-radioactive nuclide can be coordinated; M represents a radioactive or non-radioactive metal nuclide, or a radioactive or non-radioactive halogen nuclide; n represents an integer of 1 to 4; and m represents an integer of 0 to 10.

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