AU623408B2 - Magnetic particle-containing compositions - Google Patents

Description

applicant(s) derive(s title from actual Invenm(s) IA., assignee of the inventlon fro, the actual inventor(e).

Attestation or IegelIzation not rquired.

To: 1..ca A..he ai d. .c t l..in I" I 4. The basic application() referred to in paragraph 2 of this Declaration was/we* the first application() made in a Convention country in respect of the invention the subject of the application.

Declared at 00o Nycomed AS By: this 73ro -fz/ day of l/ovevbei 19 r OPI DATE 05/01/90 APPLN. ID 36820 89 PCT AOJP DATE 01/02/90 PCT NUMBER PCT/EP89/00613 INTERNATIONAL APPLICATION PUBLISHED UNDER THE FAI tIN JIUU KUWO iN rliY (PCT) (51) International Patent Classification 4 (11) Interkn9ubli n 4 beVj t WO 89/11873 A61K 49/00 Al (43) InternalnaPubblication Date: 14 December 1989 (14.12.89) (21) International Application Number: PCT/EP89/00613 (74) Agents: COCKBAIN, Julian et al.; Frank B. Dehn Co., Imperial House, 15-19 Kingsway, London WC2B 6UZ (22) International Filing Date: 31 May 1989 (31.05.89) (GB).

Priority data: (81) Designated States: AT (European patent), AU, BE (Euro- 8813144.6 3 June 1988 (03.06.88) GB pean patent), CH (European patent), DE (European patent), DK, FI, FR (European patent), GB, GB (European patent), IT (European patent), JP, LU (European (71) Applicant (for GB only): COCKBAIN, Julian, Roderick, Mi- patent), NL (European patent), NO, SE (European pachaelson [GB/GB]; 27 Ladbroke Road, London Wll tent), US.

3PD (GB).

(71) Applicant (for all designated States except GB US): NY- Published COMED AS [NO/NO]; Nycoveien 1-2, N-0401 Oslo 4 With international search report.

(NO).

(72) Inventors; and Inventors/Applicants (for US only) KLAVENESS, Jo [NO/ NO]; Skayen Terrasse 15, N-0276 Oslo 2 THO- MASSEN, Terje [NO/NO]; Meklenborglia 12, N-1273 Oslo 12 (NO).

(54) Title: MAGNETIC PARTICLE-CONTAINING COMPOSITIONS (57) Abstract The invention relates to the use in diagnosis or therapy, especially magnetic resonance imaging, of a combination of magnetic particles, that is particles which are ferromagnetic, ferrimagnetic, or superparamagnetic, and a chelating agent for the metal species of the magnetic particles or a bioprecursor for such a chelating agent.

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'1 i WO 89/11873 PCT/EP89/00613 1 Magnetic Particle-Containing Compositions The present invention relates to therapeutic and diagnostic compositions, in particular to parenterally administrable compositions containing magnetic particles, and to their use in methods of therapy and diagnosis, especially diagnoses employing nuclear magnetic resonance (nmr) techniques.

Compositions containing magnetic particles, that is particles which are ferromagnetic (or ferrimagnetic) or superparamagnetic, have been used widely in diagnostic investigations and therapeutic treatments.

Thus for example parenterally administered magnetic particles have been proposed for the targeting of drugs using externally applied magnetic fields (see for example Widder et al. in J. "~arm. Sci.

68: 79-82 (1979), Advances in Pharmacology and Chemotherapy 16:213 (1979) and US-A-4247406 and also Ugelstad et al. in W083/03920 (Sintef) and Morris in US-A-4331654), for the repair of vascular damage and for arterial "clamping" during surgery (see for example Perry in Proceedings Int. Adv.

Course Workshop (1977) pages 219-230 and Roth in J. Appl. Physics 40:1044-1045(1969)), for blood flow tracing (see for example Newbower in IEEE Transactions on Magnetics Mag9(3):447-450(1973)), and for killing cancer cells in vivo using the heat generated by the magnetic particles on imposition of a rapidly alternating field (see for example Ts-'^-4106488 (Gord-'- Recently, with the development of nmr in medicine, it has been shown that magnetic particles are useful both in magnetic resonance imaging (MRI) and in magnetic resonance spectroscopy (MRS).

For example the use of magnetic particles to obtain a selective signal from cancer tissue in MRS has i L 1 L I ~-Y WO 89/11873 PCT/EP89/00613 -2been described by White et al. in Proceedings of the San Francisco Workshop on Magnetic Resonance Spectroscopy in vivo April 4-5 1987, page 93 (1987) and the use of ferromagnetic and superparamagnetic particles as MRI contrast agents has been described by Nycomed AS in W085/04330.

In MRI, the contrast in the images generated may be enhanced by introducing into the zone being imaged an agent, generally referred to as a contrast agent, which affects the spin reequilibration characteristics of the nuclei (the "imaging nuclei" which generally are protons and more especially water protons) which are responsible for the resonance signals from which the images are generated. The enchanced contrast obtained with the use of contrast agents enables particular organs or tissues to be visualized more clearly by increasing or by decreasing the signal level of the particular organ or tissue relative to that of its surroundings.

Contrast agents raising the signal level of the target site relative to that of its surroundings are termed "positive" contrast agents whilst those lowering the signal level relative to surroundings are termed "negative" Contrast agents.

The majority of materials now being proposed as MRI contrast agents achieve a contrast effect because they contain paramagnetic, superparamagnetic or ferromagnetic species.

For ferromagnetic and superparamagnetic contrast agents, which are negative MRI contrast agents, the enhanced image contrast derives primarily from the reduction in the spin reequilibration coefficient known as T or as the spin-spin relaxation time, a reduction arising from the effect on the imaging nuclei of the fields generated by the ferromagnetic or superparamagnetic particles.

i' WO 89/11873 PCT/EP89/00613 -3- Paramagnetic contrast agents on the other hand may be either positive or negative MRI contrast agents. The effect of paramagnetic substances on magnetic resonance signal intensities is dependent on many factors, the most important of which are the concentration of the paramagnetic substance at the imaged site, the nature of the paramagnetic substance itself and the pulse sequence and magnetic field strength used in the imaging routine. Generally, however, paramagnetic contrast agents are positive MRI contrast agents at conventional concentrations where their T 1 lowering effect dominates but they may become negative MRI contrast agents at higher concentrations where their T 2 lowering effect is dominant. In either event, the relaxation time reduction results from the effect on the imaging nuclei of the magnetic fields generated by the paramagnetic centres.

The use of ferromagnetic and superparamagnetic materials as MRI contrast agents has been widely advocated and broad ranges of suitable materials have been suggested in the literature, such as for example in W085/04330 (Nycomed AS), W085/02772 (Schroder et US-A-4675173 (Widder), W088/00060 (Advanced Magnetics Inc.), W086/01112 (Fox Chase Cancer Center), DE-A-3443252 (Schering AG), Widder et al. AJR 148:399-404 (1987), Renshaw et al. Magnetic Resonance in Medicine 3:217-225 (1986), Saini et al. Radiology 162:211-216 (1987), Mendonca Dias et al. Magnetic Resonance in Medicine 3:328-330 (1986), Hemmingsson et al. Acta Radiologica 28:703- 705 (1987) and Bacon et al. J. Lab. Clin. Med.

110:164-171 (i987).

The literature contains many suggestions for the formulation of parenterally administrable ragnetic particle containing compositions and in particular suggests that the magnetic particles can be administered either free uncoated WO 89/11873 PCT/EP89/00613 -4 and not bound to any other substance) or coated dextran coated see for example US-A-4452773), or carried by or embedded in a matrix particle a polysaccharide see for example W085/02772), or bound to an organ- or tissue-targeting species, e.g. a biomolecule such as an antibody or a hormone (see for example W088/00060).

Parenterally administrable magnetic particles are of particular interest in the imaging of the liver and the spleen due to the action of the reticuloendothelial system in removing such particles from the blood stream. However parenterally administered magnetic particles may be caused to locate at other organs or tissues, e.g by using particles which are bound to tissue-or organ-targeting substances thus enabling contrast enhanced MR images of the targetted tissues or organs to be generated.

Furthermore the suggestion has been made in W088/00060 that the serum life of parenterally administered magnetic particles may be increased, so perhaps allowing such particles to act as blood pooling MRI contrast agents, if before administration of the magnetic particles the subject's reticuloendothelial system is "overloaded" by administration of chemically and physically similar non-magnetic particles.

It is of course desirable in both therapeutic treatments and in diagnostic investigations using magnetic particles that the magnetic particles should be excreted once they have performed their desired function. For.orally administered magnetic particles and for particles administered into organs having external voiding ducts, e.g. the bladder and the uterus, excretion of the magnetic particles is unlikely to be problematic. However for parenterally, and especially intravascularly, administered particles to be excreted they must first be broken down.

In vivo biodegradation of intravascularly administered WO 89/11873 PCT/EP89/00613 5 magnetic particles appears not to have been studied in great detail but the results of various studies do indicate that it does occur gradually over a period of days or months and that the rate of biodegradation is dependent on the nature of the particles and in particular on whether or not they are free or coated (see for example Bacon et al. supra and W088/00060) It is an object of the present invention to provide means by which biodegradation of parenterally administered magnetic particles may be facilitated or accelerated.

We have surprisingly found that the rate of degradation of parenterally, especially intravascularly, administered magnetic particles is increased in the presence of chelating agents.

Thus in one aspect the present invention provides a method of treatment or diagnostic investigation of the human or non-human animal body eg involving generating an image of said body, which method comprises parenterally administering to said body a plurality of magnetic particles, the improvement comprising administering to said body a chelating agent or bioprecursor therefor.

By a chelating agent or bioprecursor is meant an agent capable of chelating metal species of the magnetic particles (particularly iron ions) or an agent which following parenteral administration will release a chelating agent capable of chelating the metal species of the magnetic particles. The term chelating agent will howeve> be used hereafter to refer both to chelating agents and to prochelating agents those moieties of chelating agent bioprecursors which form the basis for chelating agents that will in due course be released).

Particular mention may be made of bioprecursors which comprise chelating agents tlpund by biodegradable bonds, e.g. ester linkages, to other substanies, WO 89/11873 PCT/EP89/00613 -6e.g. biomolecules (such as antibodies and hormones) or biologically relatively inert macromolecules (such as for example polysaccharides) or other matrix or carrier materials.

Where the chelating agent is bound on or to or otherwise incorporated in a further substance such further substance will be referred to herein as a carrier material. Thus typical carrier materials may be for example coatings, matrices and macromolecules and the composite chelating agent/carrier material may be particulate or not.

Where the chelating moiety of the chelating agent used according to the present invention is already chelating an ionic species on administration to the body then this ionic species clearly will most preferably one which forms a thermodynamically less stable chelate than does the metal species of the magnetic particles, e.g. an ion for which the chelate formation constant is lower (at body temperature and in blood serum) than that for iron ions. In this regard, it is thus preferred that where the chelating moiety is already chelating an ionic species that species is a Group Ia, Ib, IIa or IIb metal ion, e.g. ions of Na, K, Ca, Mg or Zn. Generally such ionic species will also be non-paramagnetic and non-radioactive and will have a charge of no more than 2+.

The method of the present invention is thus distinguished from the techniques described by Carvlin et al. at the 5th Annual Meeting of the Society for Magnetic Resonance Imaging, San Antonio, T xas, 2P Febru-1' 4 March 197 -r by Weissleder et al. in Magnetic Resonance Imaging 87 005/01 S. 00135-136, techniques which sought to improve contrast enhancement in MRI by coadministration of the paramagnetic MRI contrast agent Gd-DTPA and a super-paramagnetic MRI contrast agent comprising ferrite particles.

WO 89/11873 PCT/EP89/00613 7 In the method of the invention, the magnetic particles and the chelating agent or bioprecursor may be administered separately or, more preferably, together. Where they are administered separately, the chelating agent may be administered parenterally or, where it is absorbable, enterally. In this regard mention may be made of 1,2-dimethyl-3-hydroxypyrid-4-one as an example of an absorbable chelating agent. Furthermore, the chelating agent may be administered before, during or after administration of the magnetic particles. Thus for example it may be desirable to administer or to continue to administer the chelating agent hours or days (e.g.

up to 48 hours) after the magnetic particles have served their diagnostic or therapeutic function in order to ensure rapid degradation of the magnetic particles remaining in the body.

Preferably however the magnetic particles and the chelating agent will be coadministered and in another aspect the present invention provides a parenterally administrable composition, for use for example in therapy or diagnosis, comprising magnetic particles and a chelating agent or bioprecursor therefor in a physiologically tolerable dispersion medium.

In preferrred embodiments, the composition of the invention comprises composite particles comprising chelating agent and a carrier material or magnetic particles and a carrier material or, especially preferably, magnetic particles, chelating agent and a carrier material.

The use of c-nposite particles containing both the magnetic particles and the chelating agent is especially preferred since in this way delivery of free chelating agent to the vicinity of the magnetic particles during their biodegradation may be particularly facilitated.

WO 89/11873 PCT/EP89/00613 8 Where the chelating agent and/or magnetic particles are administered bound to or incorporated in a carrier material, the carrier may particularly conveniently be an organ- or tissue-targeting biomolecule, for example a hormone or antibody, or a biotolerable and generally biologically relatively inert material such as a polysaccharide dextran or starch), a protein albumin) or another naturally occurring or synthetic macromolecule, e.g. as described by Schroder et al. in W085/02772 or by Nycomed AS in EP-A-184899 and EP-A-186947.

Where the magnetic particles are administered in such a way as to enter particular cells, it will be desirable to attach the chelating agents, by means of biodegradable bonds, to particles, to lipophilic moieties or to biomolecules so as to facilitate the entry of the chelating agents into the targeted cells.

Where the carrier material incorporates the chelating agent, this may be for example by simple entrapment or encapsulation within a biodegradable matrix or coating material whereby the chelating agent is released, preferably on a sustained release basis, as the carrier material breaks down. Alternatively the chelating agent may be deposited in voids within matrix particles, much as described in EP-A-184899, being released from the particles either as they degrade or as it dissolves on penetration of the matrix by body fluids. As a still further alternative, the composite particles may comprise particles of an insoluble derivative pf the chelating agent which breaks down in vivo to release the chelating agent.

The chelating agent itself may conveniently be any biotolerable agent capable of chelating the metal species of the magnetic particles (especially iron ions) and in this regard particular mention may be made of the aminopolyacetic acids and of I~ WO 89/11873 PCT/EP89/00613 9 the many biotolerable chelating agents suggested in the literature for the parenteral administration of paramagnetic MRI contrast agents, see for example EP-A-184899 (Nycomed AS), EP-A-186947 (Nycomed AS), EP-71564 (Schering AG), EP-A-130934 (Schering AG), GB-A-2137612(Scherirng AG), US-A-4647447 (Schering AG), US-A-4639365 (Sherry), W085/05554 (Amersham International PLC), W087/02893 (University of Texas), W087/01594 (Amersham International PLC), EP-A-136812 (Technicare Corp.) and EP-A-160552 (Vestar Research Inc) and by Nycomed AS in WO 89/00557. Particularly preferred chelating agents may thus include transferrin, N,N,N',N",N"-diethylenetriaminepentaacetic acid (DTPA), the N,N" bismethylamide of DTPA (DTPA-BMA), l-oxa-4,7,10-triaza-cyclododecane-triacetic acid (OTTA), 1,4,7,10-tetraazacyclododecane-triacetic acid (DO3A) 1,4,7,10-tetraazacyclododecanetetraacetic acid (DOTA), desferrioxamine, ethylene-bis(2hydroxyphenylglycine) (EHPG) and derivatives thereof, e.g. salts with physiologically tolerable counterions, especialy the metal ions referred to above or a non-toxic amine tris(hydroxymethyl)-aminomethane, ethanolamine, diethanolamine and N-methylglucamine), or a halogen or a non-toxic organic or inorganic acid.

As mentioned above, in general, chelating agents used to chelate paramagnetic ions in parenterally administrable paramagnetic MRI contrast agents may be used as the chelating agents in the method of the present invention. Of particular interest however are the macromolecule -linker moiety-chelating agent compounds disclosed by Amersham in W085/05554 and more especially by Nycomed AS in European Patent Application No. 89200168.6.

Where the chelating agent is bound by a biodegradable bond to a soluble carrier material, e.g.

a dextran, then in order that the chelating agent should not be cleared from the cardiovascular system 1 WO 89/11873 PCT/EP89/00613 10 too rapidly, the carrier material/chelating agent composite will preferably have an overall molecular weight above the kidney threshold, i.e. preferably at least 20000, especially preferably 40000-2000000, particularly about 50000 to 150000. Moreover, where thechelating agent is administered in particulate form, e.g. in a composite matrix/chelating agent particle, the mean particle size will preferably be from 0.001 to 10 micrometer, especially preferably 0.01 to 5 micrometer, particularly preferably 0.05 to 2.0 micrometer.

The magnetic particles used according to the present invention may be of any material which, although preferably non-radioactive (unless the particles are intended to be detected by their radioactive decay emissions), exhibits ferromagnetism or superparamagnetism. The magnetic particles may conveniently be particles of a magnetic metal or alloy, e.g. of pure iron, but particularly preferably will be of a magnetic compound such as magnetite or a ferrite, such as for example gamma ferrite and cobalt, nickel or manganese ferrites.

The magnetic particles may conveniently be free or coated, aggregated or matrix carried or embedded; however the overall particle size, including any carrier material, will preferably be less than micrometers, preferably 5nm to 5 micrometers, and the magnetic particles themselves will preferably be 1.5 micrometer or less, preferably 0.1 micrometer or less and especially preferably of superparamagnetic rather than ferromagnetic dimensions subdomain sized), e.a. 5-50nm.

The particles of the superparamagnetic or ferromagnetic material may be coated or carried in or on particles of a non-magnetic matrix material, for example of a polysaccharide such as dextran or starch or a protein such asalbumin and when targeting of the ferromagnetic or superparamagnetic j WO 89/11873 PCr/EP89/0O613 11 substance onto a specific tissue is desired it may be desirable to use a ferromagnetic or superparamagnetic material which is bound to a tissue- or organspecific biomolecule, e.g. as described in W088/00060.

Where the superparamagnetic or ferromagnetic material is provided with a non-magnetic coating or matrix, the coating or matrix material is particularly preferably a polysaccharide material, such as starch or dextran (as suggested Schroder in W083/01738) or a biotolerable polymer such as is suggested by Ugelstad et al. in W083/03920.

Where the ferromagnetic or superparamagnetic material is provided with a coating or matrix, the iron content of the overall particles will preferably be from 0.1 to 80%, especially 1 to by weight.

Generally however magnetic particles as suggested by the literature may be used, e.g. magnetite dextrans as suggested by Schering AG and by Molday (in US- A-4452773) and carrier bound or free magnetic particles

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as suggested by Schroder et al, Nycomed AS and Advanced Magnetics Inc.

Where the magnetic particles are to be administered in composite particles containing carrier material, chelating agent and magnetic particles, the composite particles may for instance be prepared by precipitation of the magnetic particles and the chelating agents into a carrier material matrix using the method of Schroder et al. Alternatively such composite particles may be prepared by binding a chelating agent to a magnetic particle containing composite particle by use of a coupling agent.

The compositions of the invention may contain further components besides the chelating agent, carrier material, magnetic particles and dispersion medium water for injections or physiological saline). In particular the compositions ma$ contain viscosity modifiers, pH adjusting agents, osmolality ~~i-i WO 89/11873 PCT/EP89/00613 12 regulators, stabilizers, antioxidants, buffers and emulsifying or dispersing agents a well as other conventional pharmaceutical or veterinary formulation aids. The carrier medium will however preferably be isotonic or somewhat hypertonic.

Where the chelating agent is administered separately from the magnetic particles it too will preferably be in a standard parenteral or enteral administration form, e.g. parenteral administration forms such as solutions, suspensions or dispersions in a physiologically tolerable medium, e.g. water for injections, etc., and oral administration forms such as tablets, coated tablets, capsules, solutions, suspensions, dispersions, syrups, etc. Where the chelating agent is formulated for enteral administration, the composition may of course contain diluents, flavouring or colouring agents or other conventional pharmaceutical or veterinary formulation aids such as for example those mentioned earlier. Enteral administration forms may also, if desired, be formulated in sustained or delayed release form using conventional techniques.

The preferred dosages of the chelating agent and magnetic particles used according to the present invention will vary over a wide range and the chose dosage will depend upon such factors as the administration route, the nature of the subject, the biodistribution, pharmacokinetics and chemical nature of the materials administered the purpose of administration, (i.e.

therapy or diagnosis etc) and the characteristics of the externally imposed magnetic field, e.g.

the strength and pulse sequence used in the imaging routine. In general, for MRI the magnetic particle dosages will be similar to the conventional dosages, and thus conveniently the dosage for the ferromagnetic or, preferably, superparamagnetic substance will be in the range 0.0001 to 5 mmol/kg bodyweight, preferably 0.001-1 mMFe/kg bodyweight.

WO 89/11873 PCT/EP89/00613 13 Preferably, the molar ratio between the chelating groups of the chelating agent and the magnetic metal species Fe) in the magnetic particles should be at least 3. By increasing this ratio the half life of the magnetic particles may be reduced but the doses of chelating agent administered should not exceed and preferably should not approach closely to the toxic dosage levels.

In a further aspect of the present invention there is provided the use of magnetic particles and/or chelating agents or bioprecursors therefor in the manufacture of agents for use in a treatment or diagnosis of the human or animal body involving administration thereto of a chelating agent or bioprecursor therefor and parenteral administration thereto of magnetic particles.

The present invention will now be illustrated further with reference to the following non-limiting Examples in which ratios, percentages and parts referred to are by weight unless otherwise indicated: Example 1 Suspension containing magnetic particles and DTPA covalently linked to cross-linked starch particles 100 mg of uncoated magnetic particles (superparamagnetic particles prepared in acordance with the description on page 43 of WO 88/00060) and 1.0 g of starch gel beads (1.5 microns) containing DTPA (prepared in accordance with the first part of Example 9 of EP-A-184899) are filled into a 20 ml vial.

Before use, the particles are suspended in 10 ml of a sterile aqueous solution of 0.9 per cent NaCI by vigorous shaking for 2 minutes. The suspension contains 10 mg magnetic particles and 10Q mg DTPAstarch gel beads per ml.

The suspension is preferably administered intravenously.

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WO 89/11873 PCT/EP89/00613 -14 Example 2 Kit comprising four components: one vial containing a suspension of superparamagnetic particles and three vials containing desferrioxamine Suspension of magnetic particles 100 mg of dextran magnetite (superparamagnetic particles from Meito Sangyo, Japan) are suspended in 10 ml of an aqueous solution of 0.9 per cent NaCI and 0.1 per cent Pluronic F-68 by sonication.

The suspension is filled into a 10 ml vial and heat sterilized.

The suspension contains 10 mg dextran magnetite/ml.

Three vials containing desferrioxamine g of desferrioxamine methanesulfonate are dissolved in 30 ml of water. The solution is sterile filtered and filled into three 20 ml vials (10 ml in each) and the contents of the vials are freeze-dried.

Each vial contains 1000 mg of desferrioxamine methanesulfonate as a white powder.

Before use, the contents of each vial are dissolved in 5ml of sterile water.

Both the suspension of superparamagnetic particles and the solutions of desferrioxamine methanesulfonate are intended for parenteral administration. The suspension is preferably administered intravenously while the solutions of des£errio:c;.,,'i: a:y L- i.'liste--c intravenously or intramuscularly. If the solution is administered intravenously, it should be administered slowly to the patient at a dosage of less than mg desferrioxamine methanesulfonate per kilogram bodyweight.

i WO 89/11873 PCT/EP89/00613 15 Example 3 Kit comprising two components: one vial containing magnetic particles and one vial containing a suspension of a chelating agent Vial con'aining magnetic particles 150 mg of sterilized superparamagnetic particles (0.2 microns) coated with human serum albumin (prepared in accordance with the description on page 43 of WO 88/00060) are filled into a 20 ml vial.

Before use, the particles are suspended in 10 ml of a sterile aqueous solution of 0.9 per cent NaCl by vigoruus shaking for 2 minutes.

The suspension contains 15 mg of superparamagnetic pariticles/ml.

Suspension of chelating agent (l,2-dihydro-l-hydroxy-2-oxo-pyridin- (Zn(II)-LIHOPO) is prepared under aseptic conditions using the method of White et al., J. Med. Chem. 31, 11 (1988).

g of Zn(II)-LIHOPO (particle size less than 2 microns) are suspended in 20 ml of a sterile aqueous solution of 0.9% NaC1. The suspension is filled aseptically into a 10 ml vial.

The suspension contains 400 mg Zn(II)-LIHOPO/ml.

Both suspensions are intended for parenteral administration.

The suspension of superparamagnetic particles is preferably administered intravenously; the suspension of chelating agent is preferably administered intravenously or intramuscularly.

WO 89/11873 PCT/EP89/00613 16 Example 4 Kit comprising a suspension of magnetic particles and 5 capsules of chelating agent Suspension of magnetic particles 200 mg of heat-denatured human serum albumin microspheres containing magnetite (prepared in accordance with US-A-4675173) is suspended in 10 ml of an aqueous solution of 0.9 per cent NaCl and 0.2 per cent polysorbate 80 by sonication for 1 minute.

The suspension contains 20 mg particles/ml.

Capsules of chelating agent 2-Dimethyl-3-hydroxy-pyrid-4-one is prepared using the method of Kontohiorghes et al. Arzneimittelforschung 37 1099 (1987).

A powdery mixture was prepared from: 1,2-Dimethyl-3-hydroxy-pyrid-4-one 500 mg Amylum maydis+ q.s.

a quantity is used that is sufficient to ensure that the capsules are filled.

The powder is mixed and filled into hard gelatin capsules (Capsugel Size 0).

The suspension is preferably administered intravenously; the capsules are preferably administered orally.

Example Kit comprising a suspension of maonetic particles and a solution of ethylenediamine-di(ortho-hydroxyphenylacetic acid) (EHPG) magnetic particle containing compositions and in particular suggests that the magnetic particles can be administered either free uncoated

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WO 89/11873 PCr/EP89/00613 17 Suspension of magnetic particles Human serum albumin magnetite protein A conjugate in the form of microparticles is prepared in accordance with DE-A-3508000.

mg of these particles are filled into a 10 ml vial.

Before use, the particles are suspended in 10 ml of a sterile aqueous solution containing 0.9% Nacl and 0.1% polysorbate Solution of ethylendiamine-di (ortho-hydroxyphenylacetic acid) Ethylenediamine-di(ortho-hydroxyphenylacetic acid) (from SIGMA) 5.0 g 1 N HCL q.s.+ NaCl* q.s.

Sterile water ad 100 ml The solution is sterile filtered, filled into a 100 ml vial and freeze dried. Before use, the white powder is dissolved in 100 ml of sterile water to yield a solution containing 50 mg EHPG/ml.

2 equivalents of acid per equivalent of EHPG.

A quantity sufficient to ensure isotonicity is used.

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Claims (14)

1. A method of generating an image of a human or non-human animal body, which method comprises parenterally administering to said body a plurality of superparamagnetic, ferrimagnetic or ferromagnetic particles, the improvement comprising administering to said body a chelating agent or bioprecursor therefor, said chelating agent being other than a polysaccharide or protein.

2. A method as claimed in claim 1, comprising administering to said body an agent capable of chelating metal species of said magnetic particles, or a bioprecursor thereof.

3. A method as claimed in either one of claims 1 and 2 comprising administering to said body a said bioprecursor comprising a said chelating agent bound by a biodegradable bond to a biomolecule or to a biologically inert macromolecular matrix or carrier material.

4. A method as claimed in any one of claims 1 to 3 comprising administering said chelating agent or bioprecursor thereof in the form of a salt with a counterion selected from sodium, potassium, calcium, magnesium and zinc.

A method as claimed in any one of claims 1 to 4 wherein said magnetic particles are ferromagnetic or superparamagnetic particles.

6. A method as claimed in any one of claims 1 to 5 wherein said chelating agent or bioprecursor is co-administered with said magnetic particles. SUBSTITUTE SNiLEE i, m an r± uy coaamnnistration of the paramagnetic MRI contrast agent Gd-DTPA and a super-paramagnetic MRI contrast agent comprising ferrite particles. ii: i 19

7. A method as claimed in any one of claims 1 to 6 wherein said magnetic particles comprise superparamagnetic particles.

8. A diagnostic composition comprising composite particles comprising superparamagnetic, ferrimagnetic or ferromagnetic particles, a chelating agent or a bioprecursor thereof, and a carrier material, said chelating agent being other than a polysaccharide or protein.

9. A composition as claimed in claim 8 wherein said chelating agent and/or said magnetic particles are bound to or included within a said carrier material.

A composition as claimed in either of claims 8 and 9 wherein said chelating agent comprises an aminopolycarboxylic acid or derivative thereof.

11. A composition as claimed in any one of claims 8 to 10 comprising as said chelating agent a chelating moiety attached via an optionally biodegradable linker moiety to a macromolecule.

12. A composition as claimed in any one of claims 8 to 11 wherein said chelating agent has a molecular weight above the kidney threshold.

13. A composition as claimed in any one of claims 8 to 11 comprising composite particles of mean particle size of from 0.001 to 10 micrometers.

14. A composition as claimed in any one of claims 8 to 13 wherein said magnetic particles comprise superparamagnetic particles optionally provided with a non-magnetic matrix or coating. 00, 4 a gQ81: T2y ~~V0 71< 3$1 T UT Z C-3iT s __1 9-1 C Ay C U. LU l wiIe vicinity or tne magnetic particles during their biodegradation may be particularly facilitated. 1 :a- 20 A method of treatment or diagnostic investigation of the human or non-human animal body which method comprises parenterally administering to said body a plurality of superparamagnetic, ferrimagnetic or ferromagnetic particles, the improvement comprising administering to said body a chelating agent or bioprecursor therefor, said chelating agent being other than a polysaccharide or protein. DATED this 19th day of February, 1992. NYCOMED AS By their Patent Attorneys: CALLINAN LAWRIE C C *4 C, C C *I C *C C C CC )KcA I I I 4-i I INTERNATIONAL SEARCH REPORT International Application No PCT/EP 89/00613 1. CLASSIFICATION OF SUBJECT MATTER (it several classification symbols aDply, Indicate all) According to International Patent Classification (IPC) or to both National Classification and IPC IPC 4 A 61 K 49/00 Ii. FIELDS SEARCHED Minimum Documentation Searched 7 Classification System Classification Symbols I PC A 61 K Documentation Searched other than Minimum Documentat'n to the Extent that such Documents are Included in the Fields Searched III. DOCUMENTS CONSIDERED TO BE RELEVANT* Category Citation of Document, I" with indication, where appropriate, of the relevant passagee 5 I Relevant to Claim No. X WO, A, 85/05554 (AMERSHAM INTERNATIONAL PLC) 8-15 19 December 1985, see claims cited in the application X EP, A, 0184899 (NYEGAARD CO.) 18 June 8-15 1986, see claims; examples cited in the application X EP, A, 0186947 (NYEGAARD CO.) 9 July 1986, 8-15 see claims; examples cited in the application X EP, A, 0071564 (SCHERING AG) 9 February 8-15 1983, see page 5, examples; claims cited in the application X EP, A, 0258616 (SALUTAR, INC.) 9 March 1988, 8-15 see claims 1-4 SSpecial categories of cited documents: to later document published after the International filing date documnt defining ihe gneral state of the art which is not or priority date and not in conflict with the application but document defining the nrl o the art which not citd to understand the principle or theory underlying the considered to be of particular relevance invention earlier document but published on or after the international document of particular relevance; the claimed Invention filing date cannot be consid-red novel or cannot be considered to document which may throw doubts on priority claim(s) or involve an inventive step which is cited to establish the publication date of another document of particular relivance; the claimed Invention citation or other special reason (as specifiec) cannot be considered to involve an inventive step when the document referring to an oral disclosure, use, exhibition or document is combined with one or more other such docu. other means mente, such combination being obvious to a person skilled document published prior to the International filing date t't In the art. later than the priority date claimed document member of the same patent family IV. CERTIFICATION Date of the Actual Completion of the International Search Date of Mailing of this International Search Report 28th August 1989 2 1 SEP 1989 International Searching Authority Signature Authorized ficr EUROPEAN PATENT OFFICE WILIS Form PCTIISA/210 (second sheet) (January 195) ii, ur on particles ot a non-magnetic matrix material, for example of a polysaccharide such as dextran or starch or a protein such as.albumin and when targeting of the ferromagnetic or superparamagnet.ic I I ww wwow 1INN10mr Intrmn.tiona Aaoolcainon No, PCT/EP 89/00613 -2- III. DOCUMENTS CONSIDERED TO IB RELEVANT (CONTINUED FROM THE SECOND SHEET) Category Cifltion of Document, with indication. whre soropriate, of th rNeevant pssages Relevant to Claim No X GB, A, 2193095 (RAMOT UNIVERSITY AUTHORITY 8-15 FOR APPLIED RESEARCH AND INDUSTRIAL DEVELOPMENT LTD) 3 February 1988, see the whole document Y WO, A, 88/00060 (ADVANCED MAGNETICS INC.) 8-15 14 January 1988, see page 43 cited in the application Y Journal Medical Chemistry, vol. 31, no. 1, 8-15 1988, American Chemical Society, D.L. White et al.: "Specific sequeste- ring agents for the actinides. 1-6. Synthesis and initial testing of polydentate oxohydroxypyri- dinecarboxylate ligands", pages 11-18, see paragraph "Experimental section" cited in the application Y US, A, 4675173 WIDDER) 23 June 1987, 8-15 see column 5, lines 1-23 cited in the application Y Arzneimittelforschung/Drug. Res., vol. 37, 8-15 no. 11, 1987, G.J. Kontoghiorghes et al.: "New synthetic approach and iron chelating studies of l-alkyl-2-methyl-3-hydroxy- pyrid-4-ones", pages 1099-1102, see pages 1099-1100 cited in the application Y EP, A, 0186616 (SCHERING AG) 2 July 1986, 8-15 see page 12, example cited in the application Form PCT ISA.210 (extra Ghost) (AriUcY 1SU) i s i International Application No. PCT/EP 89/00613 FURTHER INFORMATION CONTINUED FROM THE SECOND SHEET OBSERVATIONS WHERE CERTAIN CLAIMS WERE FOUND UNSEARCHABLE i This !nternational search report has not been established In respect of certain claims under Article 17(2) for the following reasons: Claim numbers..... because they relate to subject matter not required to be searched by this Authority, namely: 1-7,16 See PCT Rule 39.1(iv): methods for treatment of the human or animal body by surgery or therapy, as well as diagnostic methods. 2.E Claim because they relate to partis of the International application that do not comply with the prescribed require- ments to such an extent that no meaningful Internatlon! search can be carried out, specfcally: Claim becuse they re depedent dclaims ad are not drafted in accordance with the econd and third sentences of PCT Rule 6.4(a). VI.Q OBSERVATIONS WHERE UNITY OF INVENTION IS LACKING Z This International Searching Authority found multiple Inventions In this International application as follows: As all required additional search fees were timely paid by the applicant, this International search report covers all searchable claims of the International application. 2. As only some of the required additional search fees were timely paid by the applicant, this International search report covers only those claims of the International application for which fees were paid, specifically claims: 3. No required additional search fees were timely paid by the applicant. Consequently, this international search report Is restricted to the invention first mentioned In the clalma; It s covered by claim numbers: 4.J As all searchableclalms -ould be searched without effort justifying an additional fee, the nternational Searching Authority did not Invite payment of any additional fee. Remark on Protest M The additional search fees were accompanied by applicant's protest. SNo protest accompanied the payment of additional search fees. Form PCTIISA/210 (supplemental sheet (January -I VV f .L LLIJ= J L Jll aL L C. or, preferably, superparamagnetic substance will be in the range 0.0001 to 5 mmol/kg bodyweight, preferably 0.001-1 mMFe/kg bodyweight. ANNEX TO THE INTERNATIONAL SEARCH REPORT ON INTERNATIONAL PATENT APPLICATION NO. EP 8900613 SA 28730 This annex lists the patent family members relating to the patent documents cited in the above-mentioned international search report. The members are as contained in the European Patent Office EDP le on 15/09/89 The European Patent Office is in no way liable for these particulars which are merely given for the purpose of information. Patent document Publication Patent family Publication cited in search report date member(s) date WO-A- 8505554 19-12-85 EP-A- 0183760 11-06-86 JP-T- 61501571 31-07-86 EP-A- 0184899 18-06-86 JP-A- 61155338 15-07-86 SE-A- 8405500 02-05-86 SE-A- 8405501 02-05-86 EP-A- 0186947 09-07-86 JP-A- 61155337 15-07-86 .SE-A- 8405499 02-05-86 EP-A- 0071564 09-02-83 DE-A- 3129906 10-02-83 AU-A- 1018688 28-04-88 AU-B- 566007 08-10-87 AU-A- 8633082 27-01-83 CA-A- 1218597 03-03-87 EP-A- 0169299 29-01-86 JP-A- 62123159 04-06-87 JP-A- 58029718 22-02-83 US-A- 4647447 03-03-87 EP-A- 0258616 09-03-88 AU-A- 7573587 11-02-88 JP-A- 63119446 24-05-88 GB-A- 2193095 03-02-88 DE-A- 3724985 11-02-88 FR-A- 2602145 05-02-88 WO-A- 8800060 14-01-88 US-A- 4827945 09-05-89 US-A- 4770183 13-09-88 EP-A- 0275285 27-07-88 JP-T- 1500196 26-01-89 US-A- 4675173 23-06-87 None EP-A- 0186616 02-07-86 DE-A- 3443251 28-05-86 DE-A- 3443252 28-05-86 DE-A- 3508000 04-09-86 AU-B- 583070 20-04-89 AU-A- 5022585 29-05-86 CA-A- 1252950 18-04-89 Z For more details about this annex see Official Journal of the European Patent Office, No. 12/82 The suspension is preferably administered' intravenously,. I. ANNEX TO THE INTERNATIONAL SEARCH REPORT ON INTERNATIONAL PATENT APPLICATION NO. Page 2 EP 8900613 SA 28730 This annex lists the patent family members relating to the patent documents cited in the above-mentioned international search report. The members are as contained in the European Patent Office EDP file on 15/09/89 The Europcar Patent Office is in no way liable for these particulars Aihich are merely giien for the purpose of information. Patent document Putication Patent family Publication cited in search report oate member(s) date EP-A- 0186616 JP-A,- 61171434 02-08-86 Z For more details about this annex :see Official .Joirnal of the 17 iropean Patent Office, No. 12/82