Indocyanine green drug impurity as well as preparation method and application thereof

Abstract

The invention discloses an indocyanine green drug impurity compound as shown in a formula (I) and a preparation method and application thereof. The preparation method is simple in steps and operation, raw materials are easy to obtain, the required high purity can be achieved through common refining, and the indocyanine green drug impurity compound can be used as an impurity reference substance. # imgabs0 #

Description

Technical Field

[0001] The present invention belongs to the field of pharmaceutical chemistry, and particularly relates to a preparation method of an impurity of indocyanine green drug. Background Art

[0002] Indocyanine green (ICG) belongs to fluorescent tricarbocyanine dyes and is a fully synthetic tricarboxycyanine-based diagnostic reagent, also known as indocyanine green. It was developed by the Kodak laboratory in the United States in 1955. In 1956, Fox et al. first applied it to the examination of liver function and circulatory function. Since 1970, it has been widely used in ophthalmic angiography. Currently, indocyanine green for injection is used to determine cardiac output, liver function and hepatic blood flow detection, choroidal angiography, etc.

[0003]

[0004] Drug impurities generally refer to all other chemical substances other than the target compound introduced or generated during the production, storage or use of drugs. The presence of impurities in drugs will affect the efficacy of drugs and may cause other toxic and side effects, so they must be strictly controlled.

[0005] Indocyanine green is prone to deterioration when exposed to light and heat, and its aqueous solution is very unstable. An unknown impurity will be quickly degraded during the production process of its preparation, and this impurity peak can be detected in marketed products. However, so far, there have been no relevant reports on the preparation and structure confirmation of this impurity. Summary of the Invention

[0006] The present invention provides an indocyanine green degradation impurity with the structure shown in formula (I), a preparation method thereof and its use.

[0007] The object of the present invention is achieved by the following technical solutions:

[0008] An indocyanine green degradation impurity compound with the structure shown in formula (I), its molecular formula is C 18 H 21 NO4S, and the molecular weight is 347.43.

[0009]

[0010] The present invention also provides a preparation method of the indocyanine green impurity compound shown in the above formula (I), which comprises the following steps:

[0011] (1) React indocyanine green with an oxidant in a solvent;

[0012] (2) Add a poor solvent of indocyanine green to the reaction solution to precipitate a solid.

[0013] (3) The solution from which solids have been removed is concentrated to obtain a residue, and the target compound is obtained by recrystallization with a solvent.

[0014] According to the preparation method of the present invention, in step (1):

[0015] The oxidizing agent may be any one or a combination of inorganic peroxides (such as hydrogen peroxide, calcium peroxide, barium peroxide, etc.) or organic peroxides (such as m-chloroperbenzoic acid, tert-butyl hydroperoxide, peracetic acid, etc.), among which concentrated hydrogen peroxide solution (30% w / w), barium peroxide, m-chloroperbenzoic acid, and tert-butyl hydroperoxide are preferred.

[0016] The solvent may be purified water, alcohol (such as methanol, ethanol, isopropanol, etc.) or a mixture of purified water and alcohol, among which methanol is preferred;

[0017] The reaction temperature of the reaction is 0 to 100 °C, among which 10 to 30 °C is preferred;

[0018] The molar ratio of indocyanine green to the oxidizing agent is 1:1 to 1:10, among which 1:3 to 1:5 is preferred.

[0019] According to the preparation method of the present invention, in step (2):

[0020] The poor solvent for indocyanine green is ketones (such as acetone, butanone, methyl isobutyl ketone, etc.);

[0021] The volume ratio of the poor solvent for indocyanine green to the reaction solution is 3:1 to 10:1 (v / v), among which 5:1 to 7:1 (v / v) is preferred.

[0022] According to the preparation method of the present invention, in step (3):

[0023] Solids are removed by filtration, and the filtrate is concentrated under reduced pressure to obtain a residue;

[0024] The solvent for recrystallization is a mixed solvent of alcohol and ketone, preferably a mixed solvent of methanol and acetone;

[0025] In the mixed solvent, the volume ratio of methanol to acetone is 1:1 to 1:5 (v / v), among which 1:2 to 1:3 (v / v) is preferred;

[0026] After adding the mixed solvent, it is heated to 30 to 60 °C, preferably 40 to 50 °C, to dissolve the residue, and then cooled for crystallization, preferably cooled for crystallization at 0 to 5 °C.

[0027] In one embodiment of the present invention, indocyanine green reacts with a 30% concentrated hydrogen peroxide solution in a solvent of methanol, purified water, absolute ethanol, or a mixed solvent with a volume ratio of water to methanol of 1:1.

[0028] In one embodiment of the present invention, indocyanine green reacts with barium peroxide in the solvent methanol or purified water.

[0029] In one embodiment of the present invention, indocyanine green reacts with m-chloroperbenzoic acid in the solvent methanol or purified water.

[0030] In one embodiment of the present invention, indocyanine green reacts with tert-butyl hydroperoxide in the solvent methanol or purified water.

[0031] The present invention also provides the application of the indocyanine green impurity compound shown in the above formula (I), which is used for the quality control of the drug indocyanine green and is used as an impurity reference substance.

[0032] Beneficial effects:

[0033] In the detection of indocyanine green in the prior art, an impurity peak at one position is found. At present, this impurity is not specified in the quality standards of indocyanine green raw materials and preparations (indocyanine green for injection) included in the United States Pharmacopeia (USP) and the Chinese Pharmacopeia (ChP) (both are controlled as unknown impurities). The present invention prepares this degradation impurity of indocyanine green (such as formula I) and confirms its structure. Its chemical name is 3,3-dimethyl-2-hydroxy-1-(4-sulfobutyl)-4,5-benzindole inner ammonium salt. The preparation method of the present invention has simple steps and operations, easily available raw materials, and can achieve high purity through ordinary purification, and can be used as an impurity reference substance. Description of the drawings

[0034] Figure 1 : HPLC chromatogram of the product prepared in Example 1;

[0035] Figure 2 : Mass spectrum of the product prepared in Example 1;

[0036] Figure 3 : 1H NMR spectrum of the product prepared in Example 1;

[0037] Figure 4 : 13C NMR spectrum of the product prepared in Example 1;

[0038] Figure 5 : HPLC chromatogram of the product prepared in Example 2;

[0039] Figure 6 : HPLC chromatogram of the product prepared in Example 3;

[0040] Figure 7 : HPLC chromatogram of the product prepared in Example 4;

[0041] Figure 8: HPLC chromatogram of the product prepared in Example 5;

[0042] Figure 9 : HPLC chromatogram of the product prepared in Example 6;

[0043] Figure 10 : HPLC chromatogram of the product prepared in Example 7;

[0044] Figure 11 : HPLC chromatogram of the product prepared in Example 8;

[0045] Figure 12 : HPLC chromatogram of the product prepared in Example 9;

[0046] Figure 13 : HPLC chromatogram of the product prepared in Example 10. Detailed implementation mode

[0047] The preparation method of the compound of formula I of the present invention will be further described in detail below with reference to specific examples. It should be understood that the following examples are only for illustrative and explanatory purposes of the present invention, and should not be construed as limiting the protection scope of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection of the present invention.

[0048] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods; unless otherwise specified, the reagents, materials, etc. used in the following examples can all be obtained from commercial sources.

[0049] Example 1

[0050] Take 10.0 g (0.0129 mol) of indocyanine green into 120 ml of methanol, stir to dissolve, add 4.4 ml (0.0387 mol) of concentrated hydrogen peroxide solution (30%), stir at 10 - 30 °C until the indocyanine green reacts completely (TLC: ethyl acetate / methanol / triethylamine = 3:1:0.05). After the reaction is completed, add 600 ml of acetone to the reaction solution under stirring, filter, and concentrate the filtrate under reduced pressure to dryness. Add 30 ml of a mixed solvent of methanol and acetone (1:2 v / v) to the obtained residue, heat to 40 - 50 °C, stir to dissolve the residue, cool the reaction solution to 0 - 5 °C, crystallize for 2 - 4 hours, filter, wash the filter cake with acetone (10 ml × 2) to obtain a white solid, and dry to obtain 2.4 g of the target compound (Ⅰ), yield: 53.6%; purity 96.39% (HPLC), see Figure 1 .

[0051] MS: 346 (M - H) - See Figure 2 .

[0052] 1HNMR(600 MHz, DMSO-d6) δ 7.92 - 7.98 (m, 1H), 7.90 - 7.91 (m, 2H), 7.47 - 7.52 (m, 2H), 7.33 - 7.36 (m, 1H), 3.75 - 3.77 (t, 2H), 2.44 - 2.47 (t, 2H), 1.68 - 1.71 (m, 2H), 1.59 - 1.63 (m, 2H), 1.50 (s, 6H), 1.00 - 1.01 (s, 1H) See Figure 3 。

[0053] 13 CNMR(600 MHz, DMSO-d6) δ 181.24, 139.33, 129.90, 129.54, 128.90, 128.78, 127.00, 126.26, 123.22, 121.93, 110.70, 50.91, 44.88, 39.91, 39.09, 26.69, 23.74, 22.44 See Figure 4 。

[0054] Example 2

[0055] Take 10.0 g (0.0129 mol) of self-made indocyanine green into 120 ml of purified water, stir to dissolve, add 4.4 ml (0.0387 mol) of concentrated hydrogen peroxide solution (30%), stir at 10 - 30 °C until the indocyanine green reaction is complete (TLC: ethyl acetate / methanol / triethylamine = 3:1:0.05). After the reaction is completed, add 600 ml of acetone to the reaction solution under stirring, filter, concentrate the filtrate under reduced pressure to dryness. Add 30 ml of a mixed solvent of methanol and acetone (1:2 v / v) to the obtained residue, heat to 40 - 50 °C and stir to dissolve the residue. Cool the reaction solution to 0 - 5 °C and crystallize for 2 - 4 hours, filter, wash the filter cake with acetone (10 ml × 2) to obtain an off-white solid, and dry to obtain 1.3 g of the target compound (Ⅰ), yield: 29.0%; purity 91.87% (HPLC) See Figure 5 。

[0056] Example 3

[0057] Take 10.0 g (0.0129 mol) of self-made indocyanine green and add it to 120 ml of absolute ethanol. Stir to dissolve it, then add 4.4 ml (0.0387 mol) of concentrated hydrogen peroxide solution (30%). Stir at 10 - 30 °C until the indocyanine green reaction is complete (TLC: ethyl acetate / methanol / triethylamine = 3:1:0.05). After the reaction is completed, add 600 ml of acetone to the reaction solution with stirring, filter, and concentrate the filtrate under reduced pressure to dryness. Add 30 ml of a mixed solvent of methanol and acetone (1:2 v / v) to the obtained residue, heat to 40 - 50 °C, and stir to dissolve the residue. Cool the reaction solution to 0 - 5 °C and crystallize for 2 - 4 hours. Filter, wash the filter cake with acetone (10 ml × 2) to obtain an off-white solid, and dry to obtain 0.8 g of the target compound (I), yield: 17.8%; purity 85.29% (HPLC), see Figure 6 。

[0058] Example 4

[0059] Take 10.0 g (0.0129 mol) of self-made indocyanine green, add 60 ml of purified water and 60 ml of methanol, stir to dissolve it, then add 4.4 ml (0.0387 mol) of concentrated hydrogen peroxide solution (30%). Stir at 10 - 30 °C until the indocyanine green reaction is complete (TLC: ethyl acetate / methanol / triethylamine = 3:1:0.05). After the reaction is completed, add 600 ml of acetone to the reaction solution with stirring, filter, and concentrate the filtrate under reduced pressure to dryness. Add 30 ml of a mixed solvent of methanol and acetone (1:2 v / v) to the obtained residue, heat to 40 - 50 °C, and stir to dissolve the residue. Cool the reaction solution to 0 - 5 °C and crystallize for 2 - 4 hours. Filter, wash the filter cake with acetone (10 ml × 2) to obtain an off-white solid, and dry to obtain 1.6 g of the target compound (I), yield: 35.7%; purity 90.12% (HPLC), see Figure 7 。

[0060] Example 5

[0061] Take 10.0 g (0.0129 mol) of self-made indocyanine green and add it to 120 ml of methanol. Stir to dissolve it, then add 6.55 g (0.0387 mol) of barium peroxide. Stir at 10 - 30 °C until the indocyanine green reaction is complete (TLC: ethyl acetate / methanol / triethylamine = 3:1:0.05). After the reaction is completed, add 600 ml of acetone to the reaction solution with stirring, filter, and concentrate the filtrate under reduced pressure to dryness. Add 30 ml of a mixed solvent of methanol and acetone (1:2 v / v) to the obtained residue, heat to 40 - 50 °C, and stir to dissolve the residue. Cool the reaction solution to 0 - 5 °C and crystallize for 2 - 4 hours. Filter, wash the filter cake with acetone (10 ml × 2) to obtain an off-white solid, and dry to obtain 1.9 g of the target compound (I), yield: 42.4%; purity: 75.74% (HPLC), see Figure 8 。

[0062] Example 6

[0063] Take 10.0 g (0.0129 mol) of self-made indocyanine green and add it to 120 ml of purified water. Stir to dissolve it. Add 6.55 g (0.0387 mol) of barium peroxide and stir at 10 - 30 °C until the indocyanine green reaction is complete (TLC: ethyl acetate / methanol / triethylamine = 3:1:0.05). After the reaction is completed, add 600 ml of acetone to the reaction solution with stirring, filter, and concentrate the filtrate under reduced pressure to dryness. Add 30 ml of a mixed solvent of methanol and acetone (1:2 v / v) to the obtained residue, heat to 40 - 50 °C, and stir to dissolve the residue. Cool the reaction solution to 0 - 5 °C and crystallize for 2 - 4 hours. Filter, wash the filter cake with acetone (10 ml × 2) to obtain an off-white solid, and dry to obtain 0.95 g of the target compound (I), yield: 21.2%; purity: 70.08% (HPLC), see Figure 9 。

[0064] Example 7

[0065] Take 10.0 g (0.0129 mol) of self-made indocyanine green and add it to 120 ml of methanol. Stir to dissolve it. Add 6.7 g (0.0388 mol) of m-chloroperbenzoic acid and stir at 10 - 30 °C until the indocyanine green reaction is complete (TLC: ethyl acetate / methanol / triethylamine = 3:1:0.05). After the reaction is completed, add 600 ml of acetone to the reaction solution with stirring, filter, and concentrate the filtrate under reduced pressure to dryness. Add 30 ml of a mixed solvent of methanol and acetone (1:2 v / v) to the obtained residue, heat to 40 - 50 °C, and stir to dissolve the residue. Cool the reaction solution to 0 - 5 °C and crystallize for 2 - 4 hours. Filter, wash the filter cake with acetone (10 ml × 2) to obtain a yellow solid, and dry to obtain 0.63 g of the target compound (I), yield: 14.1%; purity: 68.84% (HPLC), see Figure 10 。

[0066] Example 8

[0067] Take 10.0 g (0.0129 mol) of self-made indocyanine green and add it to 120 ml of purified water. Stir to dissolve it, then add 6.7 g (0.0388 mol) of m-chloroperbenzoic acid and stir at 10 - 30 °C until the indocyanine green reaction is complete (TLC: ethyl acetate / methanol / triethylamine = 3:1:0.05). After the reaction is completed, add 600 ml of acetone to the reaction solution with stirring, filter, and concentrate the filtrate under reduced pressure to dryness. Add 30 ml of a mixed solvent of methanol and acetone (1:2 v / v) to the obtained residue, heat to 40 - 50 °C, and stir to dissolve the residue. Cool the reaction solution to 0 - 5 °C and crystallize for 2 - 4 hours. Filter, wash the filter cake with acetone (10 ml × 2) to obtain a yellow solid, and dry to obtain 0.59 g of the target compound (I), yield: 13.2%; purity: 47.62% (HPLC), see Figure 11 。

[0068] Example 9

[0069] Take 10.0 g (0.0129 mol) of self-made indocyanine green, add 120 ml of methanol, stir to dissolve it, then add 3.49 g (0.0387 mol) of tert-butyl hydroperoxide and stir at 10 - 30 °C until the indocyanine green reaction is complete (TLC: ethyl acetate / methanol / triethylamine = 3:1:0.05). After the reaction is completed, add 600 ml of acetone to the reaction solution with stirring, filter, and concentrate the filtrate under reduced pressure to dryness. Add 30 ml of a mixed solvent of methanol and acetone (1:2 v / v) to the obtained residue, heat to 40 - 50 °C, and stir to dissolve the residue. Cool the reaction solution to 0 - 5 °C and crystallize for 2 - 4 hours. Filter, wash the filter cake with acetone (10 ml × 2) to obtain a brown solid, and dry to obtain 0.63 g of the target compound (I), yield: 14.1%; purity 70.80% (HPLC), see Figure 12 。

[0070] Example 10

[0071] Take 10.0 g (0.0129 mol) of self-made indocyanine green, add 120 ml of purified water, stir to dissolve it, then add 3.49 g (0.0387 mol) of tert-butyl hydroperoxide and stir at 10 - 30 °C until the indocyanine green reaction is complete (TLC: ethyl acetate / methanol / triethylamine = 3:1:0.05). After the reaction is completed, add 600 ml of acetone to the reaction solution with stirring, filter, and concentrate the filtrate under reduced pressure to dryness. Add 30 ml of a mixed solvent of methanol and acetone (1:2 v / v) to the obtained residue, heat to 40 - 50 °C, and stir to dissolve the residue. Cool the reaction solution to 0 - 5 °C and crystallize for 2 - 4 hours. Filter, wash the filter cake with acetone (10 ml × 2) to obtain an off-white solid, and dry to obtain 0.95 g of the target compound (I), yield: 21.2%; purity 80.66% (HPLC), see Figure 13 。

[0072] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A compound having the structure shown in formula (I), with the molecular formula C 18 H 21 NO4S, a molecular weight of 347.43, 2. The preparation method of the compound with the structure shown in formula (I) according to claim 1, which comprises the following steps: (1) Indocyanine green reacts with an oxidant in a solvent; (2) An antisolvent of indocyanine green is added to the reaction solution to precipitate a solid; (3) The solution of the solid is concentrated to obtain a residue, and the residue is recrystallized with a solvent to obtain the target compound.

3. According to the preparation method of claim 2, in step (1): The oxidant can be any one or a combination of inorganic peroxides (such as hydrogen peroxide, calcium peroxide, barium peroxide, etc.) or organic peroxides (such as m-chloroperbenzoic acid, tert-butyl hydroperoxide, peracetic acid, etc.), among which concentrated hydrogen peroxide solution, barium peroxide, m-chloroperbenzoic acid, tert-butyl hydroperoxide are preferred; The solvent can be purified water, alcohol (such as methanol, ethanol, isopropanol, etc.) or a mixture of purified water and alcohol, among which methanol is preferred; The reaction temperature of the reaction is 0 - 100 °C, preferably 10 - 30 °C; and / or The molar ratio of indocyanine green to the oxidant is 1:1 - 1:10, preferably 1:3 - 1:

5.

4. According to the preparation method of claim 2, in step (2): The antisolvent of indocyanine green is a ketone (such as acetone, butanone, methyl isobutyl ketone, etc.); and / or The volume ratio of the antisolvent of indocyanine green to the reaction solution is 3:1 - 10:1 (v / v), preferably 5:1 - 7:1 (v / v).

5. According to the preparation method of claim 2, in step (3): The solid is removed by filtration, and the filtrate is concentrated under reduced pressure to obtain a residue; The solvent for recrystallization is a mixed solvent of alcohol and ketone, preferably a mixed solvent of methanol and acetone; In the mixed solvent, the volume ratio of methanol to acetone is 1:1 - 1:5 (v / v), preferably 1:2 - 1:3 (v / v); and / or After adding the solvent, it is heated to 30 - 60 °C, preferably 40 - 50 °C, to dissolve the residue, and then cooled for crystallization, preferably cooled for crystallization at 0 - 5 °C.

6. According to the preparation method of claim 2, indocyanine green reacts with a 30% concentrated hydrogen peroxide solution in a solvent of methanol, purified water, absolute ethanol or a mixed solvent with a volume ratio of water to methanol of 1:

1.

7. According to the preparation method of claim 2, indocyanine green reacts with m-chloroperbenzoic acid in a solvent of methanol or purified water.

8. According to the preparation method of claim 2, indocyanine green reacts with tert-butyl hydroperoxide in a solvent of methanol or purified water.

9. The application of the compound shown in formula (I) according to claim 1, which is used for the quality control of the drug indocyanine green and is used as an impurity reference substance.

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