DE19631544A1 - Diagnostic or radiotherapy compsns. contg. metal clusters - e.g. as X=ray or NMR contrast agents, having good compatibility and stability in vivo and in vitro - Google Patents

Abstract

The use of metal clusters (I) is claimed for the prepn. of compsns. for medical diagnosis or radiotherapy. (I) are specifically electrochemically pptd. metal clusters.

Description

Subject of the invention

The invention relates to the counter characterized in the claims stands, that is, the use of metal clusters as contrast agents and as therapeutic agents in radiation therapy.

State of the art

Contrast agents are indispensable for medical diagnostics, both in the magnetic resonance and in the X-ray range. Various classes of contrast media for routine diagnosis are currently available or are in development. The most important class are the extra cellular contrast agents (e.g. Ultravis® or Magnevis®), whose behavior is characterized by the fact that they distribute rapidly in the intra-cellular space after the injection and are then excreted renally. These substances are suitable for imaging vessels and some organs such as the liver and kidney. The disadvantage, however, is that the distribution into the extracellular space is extremely rapid, so that only a few minutes are available for imaging.

In order to avoid this disadvantage, has been intensively after others for a long time Wanted classes of contrast media. For example, the use described by high molecular contrast media in the hope of finding a to ensure a longer dwell time in the intravascular space in order to become one improved visualization of the vascular system. Furthermore, the Injection of particulate contrast media such as B. Suspensions of iron oxide particles (magnetites) or of poorly soluble iodine-containing compounds or of emulsions e.g. B. in the form of liposomally encapsulated MRI or X-ray contrast media called. These particulate contrast agents are preferably taken up by macrophages and are therefore for display the liver or spleen.

Surprisingly, it has now been found that metal clusters in particular those that have been solubilized by surface modifications as Contrast agents are suitable for magnetic resonance or X-ray imaging. Another application opens up for use in the Radiotherapy of tumors.

Description of the subject matter of the invention

The present invention relates to the use of metal Clusters in diagnostics and in radiation therapy.

The metal clusters are particles, the metals of order numbers 20-32, 38-51 or 56-83 contain the colloids in aqueous solution are present and can reach concentrations of 1 mol / l. The Surface modification is preferably carried out by amines or phosphines, be particularly preferably by tetraalkylammonium or tetraalkylphosphonium ions that are fixed to the surface. But others are also possible, physiologically acceptable agents, such as. B. polysaccharides (sugar, starch, Dextrans or similar). Varying the particle size and charge causes one Change in colloidal properties. The size of the particles is below half of 5 µm, ideally in the lower nanometer range. Variation of The size of the particles changes the imaging properties. Larger particles are used for the representation of the vessels, smaller particles for the representation of the Liver or spleen preferred.

The representation and characterization of the metal clusters takes place according to common Methods, e.g. B. that of M. Reetz et al. proposed electrochemical Methods (see, for example: J. Am. Chem. Soc. 1994, 116: 7401-2 or Science 1995, 267: 367-9).

The clusters can be varied by varying the manufacturing conditions Requirements of different diagnostic and therapeutic Methods are adapted. By choosing the metals in the manufacturing process z. B. the effect on X-rays or on the relaxation behavior influenced by protons. By choosing the electrochemical conditions at the charge and / or oxidation state of the clusters or of the individual metal atoms affected, properties that in turn also change the relaxation behavior of protons. By choosing the means that influence the surface of the clusters (e.g .: tetraalkylammonium and -phosphonium compounds), in particular the physiological Properties of the clusters are affected. Those skilled in the art can choose the appropriate raw materials according to his needs and the Adapt clusters to the respective application.

The pharmaceutical compositions according to the invention are produced in known manner by using the clusters according to the invention - if necessary with the addition of the additives common in galenics - in suspended or dissolves aqueous medium and then the suspension or sterilized solution if necessary. Suitable additives are, for example physiologically acceptable buffers (such as tromethamine), low Additions of complexing agents (such as EDTA, DTPA or derivatives thereof) and / or their calcium, magnesium or zinc complexes or if desired, electrolytes (such as sodium chloride) and Antioxidants (such as ascorbic acid).

Are suspensions or for enteral administration or other purposes Solutions of the agents according to the invention in water or physiological If saline solution is desired, it will be combined with one or more of those in galenics usual auxiliaries, such as methyl cellulose, lactose or mannitol, and / or surfactants, such as, for example, lecithins, Tween® or Myrj®, and / or Flavoring agents for flavor correction, such as essential oils, mixed.  

In principle, it is also possible to use the pharmaceutical according to the invention Means can also be produced without isolating the clusters. In any case, it must care is taken that the agents according to the invention are practically free of unbound toxic metal ions.

This can be done, for example, with the help of color indicators such as xylenol orange guaranteed by control titrations during the manufacturing process will.

The pharmaceutical compositions according to the invention preferably contain 1 µMol / l-1 Mol / l of the clusters and are usually in amounts of Dosed 0.001-20 mmol / kg body weight. They are for enteral and parenteral application.

The metal clusters according to the invention are used:

• 1. for NMR diagnostics in the form of their paramagnetic, superpara magnetic or ferromagnetic clusters. Particularly suitable are clusters that contain, for example, chrome, iron, manganese, cobalt, nickel, Copper, praseodymium, neodymium, samarium, gadolinium, terbium, Contain dysprosium, holmium, erbium and / or ytterbium.
• 2. for X-ray diagnostics in the form of clusters with elements higher Atomic number showing adequate absorption of x-rays guarantee. It has been found that clusters according to the invention which Elements of ordinal numbers 56-83 contain for this application are particularly suitable.
• 3. for X-ray therapy in the form of clusters containing metals with suitable k-edge (e.g. gadolinium).
• 4. for radio diagnostics and radiotherapy in the form of their clusters radioactive metals. Radioisotopes of the Elements copper, cobalt, gallium, germanium, yttrium, holmium, Lutetium, scandium, iron, europium, technetium, indium, ytterbium, Gadolinium, Samarium and Iridium.

The paramagnetic, superparamagnetic or Ferromagnetic agents meet the diverse requirements for Suitability as a contrast medium for magnetic resonance imaging. So they are forth outstandingly suitable after oral or parenteral application Increasing the signal intensity with the help of an MRI scanner to improve the meaning of the image obtained. They also show the high effectiveness that is necessary to keep the body as low as possible Amounts of foreign substances and the good tolerance that is necessary to maintain the non-invasive nature of the examinations to obtain.

In general, the agents according to the invention for use as NMR diagnostics in amounts of 0.001-5 mmol / kg body weight, preferably wise 0.005-0.5 mmol / kg body weight, dosed. Details of the application are described, for example, in H. J. Weinmann et al., Am. J. of Roentgenology 142, 619 (1984).

Particularly low doses (below 1 mg / kg body weight) of organ Specifically coated clusters are for example for the detection of tumors and usable from heart attack.

Furthermore, the complex compounds according to the invention can advantageously be used as Susceptibility reagents and as shift reagents for in vivo NMR Spectroscopy can be used.

The agents according to the invention are also outstanding as X-rays Contrast medium suitable, it should be emphasized that with them no signs of those known from the iodine-containing contrast media anaphylaxis-like reactions in biochemical-pharmacological Let examinations be recognized. The substances according to the invention meet the diverse requirements for contrast agents in the modern diagnostics are to be made. The connections and out of them provided funds are characterized by

• - a high absorption coefficient for X-rays,
• - good tolerance,
• - high effectiveness,  
• - a low viscosity,
• - low osmolality,
• - a favorable excretion rate.

In addition to the surprisingly good tolerability of the heavy metal clusters the compounds of the invention in X-ray diagnostics positive that the clusters according to the invention in particular also sub allow searches with short-wave X-rays than this with conventional contrast media is possible, whereby the radiation exposure of the Patient is significantly reduced, as is known, soft radiation from Tissue is absorbed much more strongly than hard tissue [R. Felix, "The X-ray picture"; Thieme-Verlag Stuttgart (1980)].

Because of the favorable absorption properties of the invention Contrast agents in the area of hard X-rays are also the agents especially for digital subtraction techniques (those with higher tubes voltages work).

Details of the use of X-ray contrast media are, for example, in Barke, X-ray contrast media, G. Thieme, Leipzig (1970) and P. Thurn, E. Bücheler "Introduction to X-ray Diagnostics", G. Thieme, Stuttgart, New York (1977) discussed.

In general, the agents according to the invention for use as X-ray contrast media in amounts of 0.1-20 mmol / kg body weight preferably dosed 0.25-5 mmol / kg body weight.

If the agents according to the invention are radioactive, they are due to their favorable properties and the good stability of the contained therein Complex compounds also suitable as radio diagnostics. Details of their Application and dosage are e.g. B. in "Radiotracers for Medical Applications ", CRC Press, Boca Raton, Florida.

Another imaging method with radioisotopes is the positron Emission tomography, the positron emitting isotopes such. B. ⁴³Sc, ⁴⁴Sc, ⁵²Fe, ⁵⁵Co and ⁶⁶Ga used [Heiss, W. D .; Phelps, M.E .; positron  Emission Tomography of Brain, Springer-Verlag Berlin, Heidelberg, New York (1983)].

The compounds of the invention can also be used in radioimmuno or Radiotherapy can be used. This differs from the appropriate diagnostics only by the amount and type of used Isotope. The goal is the destruction of tumor cells by high-energy short-wave radiation with the shortest possible range. Suitable β emitting ions are e.g. B. ⁴⁶Sc, ⁴⁷Sc, ⁴⁸Sc, ⁷²Ga, ⁷³Ga and ⁹⁰Y. Suitable a-emitting ions with short half-lives are e.g. B. 211 Bi, ²¹²Bi, ²¹³Bi, ²¹⁴Bi, with ²¹²Bi is preferred. A suitable photon and Electron-emitting ion is ¹⁵⁸Gd, which is ¹⁵⁷Gd by neutron capture can be obtained.

Is the agent according to the invention for use in the R. L. Mills et. al. [Nature Vol. 336, (1988), p. 787] proposed variant of the rays therapy is determined, the central ion must move from a Mössbauer isotope, such as ⁵⁷Fe or ¹⁵¹Eu.

Details of the use of radiotherapeutics are e.g. B. R. W. Kozak et al., TIBTEC, October 1986, 262.

The application of the aqueous X-ray and NMR contrast medium solutions can enterally or parenterally, e.g. B. oral, rectal, intravenous, intraarterial, intravascular, intracutaneous, subcutaneous (lymphography), subarachnoidal (myelography) take place, with intravenous application being preferred.

The agents according to the invention not only have a high stability in vitro, but also a surprisingly high stability in vivo, so that a release or an exchange of the - partially toxic - ions in the clusters within the time in which the new contrast agent is completely out again be divorced, not done.

Overall, it has been possible to synthesize new means, the new possibility open up capabilities in diagnostic and therapeutic medicine. The The invention therefore relates to the use of those mentioned in the claims Cluster in diagnostics and therapy.

Examples

The following examples are intended to illustrate the subject matter of the invention without it want to limit to this.

example 1 Palladium colloid stabilized by N-octyl-N, N-dimethyl-3-ammonio-1-propanesulfonate

It is in a universal electrolyte cell (volume 150 ml) with two platinum sheet (thickness 1 mm, distance 5 mm, electrode area 10 cm²) 100 ml one 0.1 m solution of N-octyl-N, N-dimethyl-3-ammonio-1-propanesulfonate in submitted anhydrous tetrahydrofuran. Now, with stirring, 0.6 g Palladium acetate dissolved, taking this and all subsequent operations under Argon can be performed. There is a current flow between the electrodes of 5 mA, which is increased to 35 mA within 15 minutes. Of the The contents of the cell are thermostatted to an internal temperature of 20 ° C. After one Charge flow of 500 C, the electrolysis is ended, the resulting black precipitate is filtered off with suction and washed in Vacuum dried.

Yield: 517 mg of gray-black solid
Analysis:
Found: C 16.86; H 3.10; N 1.45; S 3.63; Pd 70.21
Diameter (determined by TEM): d = 2.2 nm.

250 mg of the solid obtained by the aforementioned process is in 25 ml of 0.9% saline suspended and filled into ampoules that be heat sterilized or ultrafiltered. The colloid suspension obtained is suitable for parenteral and enteral application.

Example 2 N-octyl-N, N-dimethyl-3-ammonio-1-propanesulfonate stabilized palladium / nickel colloid

Under an argon atmosphere in a universal electrolyte cell (volume 150 ml) with a platinum anode (thickness 1 mm, electrode area 5 cm²), a nickel anode (thickness 1 mm, electrode area 5 cm²) and a platinum cathode (thickness  1 mm, electrode area 10 cm²) 100 ml of a 0.1 m solution of N-octyl-N, N- dimethyl-3-ammonio-1-propanesulfonate in anhydrous tetrahydrofuran sets. Now a between the electrodes (cathode-anode distance: 5 mm) Current flow of 5 mA applied, which increases to 35 mA within 15 minutes becomes. The contents of the cell are thermostatted to 20 ° C. After a cargo Electrolysis is terminated at a flow of 500 C, the resulting black The precipitate is filtered off with suction, washed with diethyl ether and in vacuo dried.

Yield: 517 mg of gray-black solid
Analysis:
Found: C 21.68; H 4.13; H 2.23; S 4.25; Ni 15.96; Pd 44.74
Diameter (determined by TEM): d = 2.4 nm.

250 mg of the solid obtained by the aforementioned process is in 25 ml of 0.9% saline suspended and filled into ampoules that be pasteurized or ultrafiltered. The colloid suspension obtained is for parenteral and enteral application suitable.

Example 3 Palladium colloid stabilized by N, N, N-tris [2- (2-methoxyethoxy) ethyl] -3-ammonio-1-propanesulfonate a) N, N, N-tris- [2- (2-methoxyethoxy) ethyl] -3-ammonio-1-propanesulfonate

32.3 g (100 mmol) of N, N, N-tris- [2- (2-methoxyethoxy) ethyl] amine and 10.0 g (82.7 mmol) 3-hydroxy-1-propanesulfonic acid δ-sultone are dissolved in 200 ml dry acetone heated under reflux for 12 h. The solution is evaporated to Dry and stir the residue with tert-butyl methyl ether, decant and dry the residue in vacuo.

Yield: 31.4 g (85.2% of theory) of colorless oil
Analysis:
calc .: C 48.52; H 8.82; N 3.14; O 32.32; S 7.20;
Found: C 48.43; H 8.97; N 3.07; O 032.14; S 7.10.

b) N, N, N-tris- (2- (2-methoxyethoxy) ethyl] -3-ammonio-1-propanesulfonate stabilized palladium colloid

It is in a universal electrolyte cell (volume 150 ml) with two Platinum sheets (1 mm thick, 5 mm apart, electrode area 10 cm²) 100 ml a 0.1 M solution of N, N, N-tris- [2- (2-methoxyethoxy) ethyl] -3-ammonio-1- propane sulfonate presented in anhydrous tetrahydrofuran. Now be under Stir 0.6 g of palladium acetate dissolved, this and all subsequent Operations are carried out under argon. It will be between the Electrodes have a current flow of 5 mA applied within 15 minutes Is increased by 35 mA. The content of the cell is at 20 ° C inside temperature thermostated. After a charge flow of 500 C, the electrolysis finished, the resulting black precipitate is filtered off with diethyl ether washed and dried in vacuo.

Yield: 580 mg of gray-black solid
Analysis:
Found: C 24.73; H 4.67; N 1.51; S 3.49; Pd 49.4
Diameter (determined by TEM): d = 3.2 nm.

500 mg of the solid obtained by the above process is in 25 ml of 0.9% saline suspended and filled into ampoules that be pasteurized or ultrafiltered. The colloid suspension obtained is for parenteral and enteral application suitable.

Example 4 N, N-Dimethyl-N- (2,5,8,11-tetraoxa) -tridecyl-4-ammonio-1-butanesulfonate-stabilized bismuth colloid a) N, N-Dimethyl- (2,5,8,11-tetraoxa) tridecyl-1-amine

20.8 g (100 mmol) tetraethylene glycol monomethyl ether is dissolved in 200 ml Dichloromethane dissolved. The solution is mixed with 20.8 ml (150 mmol) of triethylamine added and stirred under argon at 0 ° C. 19.1 g of 4-toluenesulfone are then added acid chloride and slowly leaves the temperature of the batch room reach temperature. After ascertained by means of thin layer chromatography complete conversion of the alcohol, the batch is stirred at 0 ° C. and gives 16.3 g (200 mmol) of dimethylamine hydrochloride and 27.7 ml (200 mmol) Triethylamine in 50 ml dichloromethane and then leaves the  Indoor temperature slowly reach room temperature again. After complete reaction is filtered, the filtrate is evaporated completely, taken up in semi-concentrated hydrochloric acid and with diethyl ether shaken out. The aqueous phase is separated off and carefully at 0 ° C. solid sodium hydroxide saturated. The aqueous phase is now used several times Extracted diethyl ether. The ether phases are combined, over anhydrous Potassium carbonate dried, filtered and evaporated. The oily residue will dried in vacuo.

Yield: 20.6 g (87.5% of theory) of colorless oil
Analysis:
calc .: C 56.14; H 10.71; N 5.95; O 27.20;
Found: C 56.00; H 10.93; N 5.72.

b) N, N-dimethyl-N- (2,5,8,11-tetraoxa) tridecyl-4-ammonio-1-butanesulfonate

11.8 g (50 mmol) of N, N-dimethyl- (2,5,8,11-tetraoxa) tridecyl-1-amine and 6.1 g (45 mmol) 4-hydroxy-1-butanesulfonic acid δ-sultone are dried in 100 ml Acetone heated under reflux for 12 h. The solution is evaporated to dryness and the residue is stirred out with tert-butyl methyl ether, decanted and dried the residue in vacuo.

Yield: 13.9 g (83.1% of theory) of colorless oil
Analysis:
calc .: C 48.50; H 8.95; N 3.77; O 30.15; S 8.63;
Found: C 48.61; H 9.11; N 3.62; S 8.77.

c) N, N-Dimethyl-N- (2,5,8,11-tetraoxa) -tridecyl-4-ammonio-1-butanesulfonate-stabilized bismuth colloid

In a universal electrolyte cell (volume 150 ml) with two platinum sheets (thickness 1 mm, distance 5 mm, electrode area 10 cm²) 100 ml of a 0.1 m solution of N, N-dimethyl-N- (2,5,8, 11-tetraoxa) -tridecyl-4-ammonio-1-butanesulfonate in anhydrous tetrahydrofuran. Now 0.6 g of bismuth acetate are dissolved with stirring, these and all subsequent operations being carried out under argon. A current of 5 mA is applied between the electrodes, which is increased to 35 mA within 15 minutes. The contents of the cell are thermostatted to an internal temperature of 20 ° C. After a charge flow of 500 C, the electrolysis is ended, the resulting black precipitate is suction filtered, washed with diethyl ether and dried in vacuo.
Yield: 547 mg of gray-black solid
Analysis:
Found: C 14.80; H 2.66; N 1.16; S 2.53; Bi 62.40
Diameter (determined by TEM): d = 2.0 nm.

125 mg of the solid obtained by the aforementioned process is in 25 ml of 0.9% saline suspended and filled into ampoules that be pasteurized or ultrafiltered. The colloid suspension obtained is for parenteral and enteral application suitable.

Example 5 (R) -3-Hydroxy-4- (trimethylammonio) butyrate stabilized gadolinium colloid

It is in a universal electrolyte cell (volume 150 ml) with two Platinum sheets (1 mm thick, 5 mm apart, electrode area 10 cm²) 100 ml a 0.1 M solution of L-carnitine in anhydrous tetrahydrofuran. Now 0.7 g of gadolinium acetate are dissolved with stirring, this and all following operations are performed under argon. It will be between a current flow of 5 mA was applied to the electrodes within 15 minutes is increased to 35 mA. The content of the cell is at 20 ° C inside temperature thermostated. After a charge flow of 500 C, the electrolysis finished, the resulting black precipitate is filtered off with diethyl ether washed and dried in vacuo.

Yield: 296 mg of gray-black solid
Analysis:
Found: C 10.78; H 1.99; N 1.93; Gd 79.33
Diameter (determined by TEM): d = 2.2 nm.

625 mg of the solid obtained by the aforementioned process is in 25 ml of 0.9% saline suspended and filled into ampoules that be heat sterilized or ultrafiltered. The colloid suspension obtained is suitable for parenteral and enteral application.  

Example 6 (R) -3-Hydroxy-4- (trimethylammonio) butyrate stabilized iron colloid

It is in a universal electrolyte cell (volume 150 ml) with two platinum sheet (thickness 1 mm, distance 5 mm, electrode area 10 cm²) 100 ml one 0.1 M solution of L-carnitine in anhydrous tetrahydrofuran submitted. Now 1.4 g of iron (II) acetate are dissolved with stirring, these and all following operations are performed under argon. It will be between a current flow of 5 mA was applied to the electrodes within 15 minutes is increased to 35 mA. The content of the cell is at 20 ° C inside temperature thermostated. After a charge flow of 500 C, the electrolysis finished, the resulting black precipitate is filtered off with diethyl ether washed and dried in vacuo.

Yield: 239 mg of gray-black solid
Analysis:
Found: C 9.35; H 1.54; N 1.84; Fe 77.36
Diameter (determined by TEM): d = 5.3 nm.

125 mg of the solid obtained by the aforementioned process is in 25 ml of 0.9% saline suspended and filled into ampoules that be heat sterilized or ultrafiltered. The colloid suspension obtained is suitable for parenteral and enteral application.

Claims (14)

1. Use of metal clusters for the production of funds for the medical diagnostics and / or radiation therapy. 2. Use of electrochemically precipitated metal clusters for the Manufacture of medical diagnostic and / or radiation agents therapy. 3. Use of metal clusters according to claim 1 or 2, characterized characterized in that metal clusters include one or more metals Atomic numbers 20-32, 38-51 or 56-83 included. 4. Use of metal clusters according to claim 1 or 2, characterized characterized in that the cluster surfaces tetraalkylammonium connections included. 5. Use of metal clusters according to claim 4, characterized records that the alkyl groups of the tetraalkylammonium compounds Hydroxyl, carboxylic acid, carboxylic acid ester, amide and / or sulfonamide contain substituents and / or ether units. 6. Use of metal clusters according to claim 1 or 2, characterized characterized in that the cluster surfaces tetraalkylphosphonium connections included. 7. Use of metal clusters according to claim 6, characterized characterized in that the alkyl groups of tetraalkylphosphonium compounds hydroxyl, carboxylic acid, carboxylic acid ester, amide and / or contain sulfonamide substituents and / or ether units. 8. Use of metal clusters according to claim 1 or 2 for the Production of contrast media for X-ray diagnostics. 9. Use of metal clusters according to claim 1 or 2 for the Production of contrast media for NMR diagnostics.   10. Use of metal clusters according to claim 1 or 2 for the Manufacture of means for radio diagnostics. 11. Use of metal clusters according to claim 1 or 2 for the Manufacture of radiotherapy agents. 12. Use of metal clusters according to claim 1 or 2 for the Manufacture of agents for neutron capture therapy. 13. Use of metal clusters according to claim 1 or 2 for the Manufacture of means for X-ray therapy. 14. Use of metal clusters according to claim 1 or 2 for the Manufacture of positron emission tomography agents.