(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2003/0232084 A1
`(43) Pub. Date:
`Dec. 18, 2003
`Groman et al.
`
`US 20030232084A1
`
`(54) POLYOL AND POLYETHER IRON OXIDE
`COMPLEXES AS PHARMACOLOGICAL
`AND/OR MRI CONTRAST AGENTS
`
`(76) Inventors: Ernest V. Groman, Brookline, MA
`(US); Kenneth G. Paul, Holliston, MA
`(US); Timothy B. Frigo, Waltham, MA
`(US); Howard Bengele, Canton, MA
`(US); Jerome M. Lewis, Newton, MA
`(Us)
`Correspondence Address:
`Barbara J. Carter
`Bromberg & Sunstein LLP
`125 Summer Street
`Boston, MA 02110-1618 (US)
`
`(21) Appl. No.:
`
`10/410,527
`
`(22) Filed:
`
`Apr. 9, 2003
`
`Related U.S. Application Data
`
`(63) Continuation-in-part of application No. 09/521,264,
`?led on Mar. 8, 2000, noW Pat. No. 6,599,498.
`
`(60) Provisional application No. 60/128,579, ?led on Apr.
`9, 1999.
`
`Publication Classi?cation
`
`(51) Int. Cl.7 ........................... .. A61K 33/26; A61K 9/14
`(52) U.S. Cl. .......................................... .. 424/486; 424/646
`
`(57)
`
`ABSTRACT
`
`Pharmacological compositions, and methods for administra
`tion, of the type employing an iron oxide complex With a
`polyol or polyether. The methods of administration may
`comprise parenteral administration of an effective dose of
`the complex formulated in a biocompatible liquid delivered
`at a rate of from about 1 mL/sec to less than 1 mL/min and
`Wherein upon administration the complex provides minimal
`detectable free iron in a subject, and minimal incidence of
`anaphylaxis. The pharmacological compositions are of the
`type employing a polyol or polyether iron oxide complex,
`Which, upon parenteral administration to a subject, are
`substantially immunosilent, provide minimal anaphylaxis
`and minimal free iron, and undergo minimal dissolution in
`vivo.
`
`Pharmacosmos, Exh. 1003, p. 1
`
`

`

`Patent Application Publication Dec. 18, 2003 Sheet 1 0f 13
`
`US 2003/0232084 A1
`
`Percent of Cross-Reactivity [Q a-Dextran florA'C-7228 versus INFeD® Using ELISA
`
`ELISA Results Using Rat Serum Raised to Dextran-BSA
`
`
`
`Cross Reactivity
`
`467%
`
`INFeD
`
`11%
`
`7228
`
`Figure: 1
`
`Pharmacosmos, Exh. 1003, p. 2
`
`

`

`Patent Application Publication Dec. 18, 2003 Sheet 2 0f 13
`
`US 2003/0232084 A1
`
`
`
`Frequency (cm-1)
`
`Figure 2
`
`Pharmacosmos, Exh. 1003, p. 3
`
`

`

`Patent Application Publication Dec. 18, 2003 Sheet 3 0f 13
`
`US 2003/0232084 A1
`
`QOUElHlUSUBJLQé
`
`
`
`1500 1(11')
`
`
`
`Fréquericy (cm-1)
`
`Figure: 3
`
`Pharmacosmos, Exh. 1003, p. 4
`
`

`

`Patent Application Publication Dec. 18, 2003 Sheet 4 0f 13
`
`US 2003/0232084 A1
`
`Figure 4
`
`
`
`
`
`E50 9651 £009“
`
`1600
`
`1600 -
`
`1400 -
`
`_ o o 3 1
`
`1200 -
`
`1100 —
`
`1000
`60
`
`62
`
`64
`
`66
`
`68
`70
`72
`[Bromuacetic acid], mglg
`
`74
`
`76
`
`80
`
`Pharmacosmos, Exh. 1003, p. 5
`
`

`

`Patent Application Publication Dec. 18, 2003 Sheet 5 0f 13
`
`US 2003/0232084 A1
`
`Q Em Q Em E Em ..
`
`
`
`E5 zoiowwzlwoa m2;
`
`on
`
`m Emmi
`
`.LD oivo
`LOO
`N (\l x— R'
`(was) Zi/L
`
`Pharmacosmos, Exh. 1003, p. 6
`
`

`

`Patent Application Publication Dec. 18, 2003 Sheet 6 0f 13
`
`US 2003/0232084 A1
`
`
`
`
`
`2:5 zoiowwzlwom m2;
`
`
`
`
`
`. oww . ow? ow? ow o
`
`w Emmi
`
`I
`
`
`
`_ _ _ _ _ I. I I | I | | | I l I | 1 1|“
`
`(was) awnzlsva r ZJJL
`
`Pharmacosmos, Exh. 1003, p. 7
`
`

`

`Patent Application Publication Dec. 18, 2003 Sheet 7 0f 13
`
`US 2003/0232084 A1
`
`Figure 7A
`
`Pharmacosmos, Exh. 1003, p. 8
`
`

`

`Patent Application Publication Dec. 18, 2003 Sheet 8 0f 13
`
`US 2003/0232084 A1
`
`Figure 7B
`
`Pharmacosmos, Exh. 1003, p. 9
`
`

`

`Patent Application Publication Dec. 18, 2003 Sheet 9 0f 13
`
`US 2003/0232084 A1
`
`Figure 8A
`
`Pharmacosmos, Exh. 1003, p. 10
`
`

`

`Patent Application Publication Dec. 18, 2003 Sheet 10 0f 13
`
`US 2003/0232084 A1
`
`Figure 8B
`
`Pharmacosmos, Exh. 1003, p. 11
`
`

`

`Patent Application Publication Dec. 18, 2003 Sheet 11 0f 13
`
`US 2003/0232084 A1
`
`Figure 9A
`
`Pharmacosmos, Exh. 1003, p. 12
`
`

`

`Patent Application Publication Dec. 18, 2003 Sheet 12 0f 13
`
`US 2003/0232084 A1
`
`Figure 9B
`
`Pharmacosmos, Exh. 1003, p. 13
`
`

`

`Patent Application Publication Dec. 18, 2003 Sheet 13 0f 13
`
`US 2003/0232084 A1
`
`Figure 10
`
`Blood Clearance in Humans at 4 mglkg
`
`(uglmL)
`
`Concentration
`
`160
`140
`120
`100
`
`4O 0 Jr
`
`0
`
`-
`
`20
`
`‘
`40
`Time (hours)
`
`_ 60
`
`Blood Clearance in Humans at 4 mglkg
`
`160
`g 140
`a 120 M
`‘3 100
`so
`=9.
`2
`~ 60
`5
`u 40
`s 20
`
`\\
`\
`\
`\
`
`7/
`/
`/
`/
`
`o o 4 I
`I
`I
`I
`l
`I
`I
`I
`f m
`(5% Q' o?’ e o" \9 v9 ‘b ,Lv- “339 41, .gb
`Time (hours)
`
`Pharmacosmos, Exh. 1003, p. 14
`
`

`

`US 2003/0232084 A1
`
`Dec. 18, 2003
`
`POLYOL AND POLYETHER IRON OXIDE
`COMPLEXES AS PHARMACOLOGICAL AND/OR
`MRI CONTRAST AGENTS
`
`CROSS REFERENCE TO RELATED
`APPLICATIONS
`
`[0001] This application is a continuation-in-part applica
`tion from US. patent application Ser. No. 09/521,264, ?led
`Mar. 8, 2000 Which in turn claims the bene?t of Provisional
`Application No. 60/128,579, ?led in the United States Patent
`and Trademark Of?ce on Apr. 9, 1999, both of Which are
`hereby incorporated by reference herein.
`
`TECHNICAL FIELD AND BACKGROUND ART
`
`[0002] The ?eld relates to complexes of polyols and
`polyethers With iron oxides including a reduced polysaccha
`ride or derivatiZed reduced polysaccharide, and methods for
`administering as pharmacological and/or MRI contrast
`agents.
`
`BACKGROUND
`
`[0003] Since the invention of magnetic resonance imaging
`(MRI), a parallel technology of injectable chemicals called
`contrast agents has developed. Contrast agents play an
`important role in the practice of medicine in that they help
`produce more useful MRI images for diagnostic purposes. In
`particular, tWo classes of imaging agents have been devel
`oped and adopted in clinical practice. These are: loW
`molecular Weight gadolinium complexes such as Mag
`navist®; and colloidal iron oxides such as Feridex I.V.® and
`Combidex®. Neither of these tWo types of agents is ideal.
`Problems encountered With these agents are shoWn in Table
`1, and include: expense of components; inef?ciency of
`synthesis; loss of coating during terminal steriliZation (auto
`claving); narroW range of organ uptake for purposes of
`imaging; toxic side-effects; restriction of use to either ?rst
`pass or equilibrium dosing, and others that are described
`herein. Agents that overcome these problems, and that
`combine the properties of these tWo types of contrast agents,
`are highly desirable.
`
`TABLE 1
`
`Comparison of ideal properties of MRI contrast agents With properties of
`lOW molecular Weight gadolinium based contrast agents and colloidal iron
`oxides.
`
`Properties of an ideal
`contrast agent
`
`lOW molecular Weight
`gadolinium
`
`colloidal iron
`oxides
`
`LoW production costs:
`ef?cient synthesis
`Autoclavable Without
`excipients
`T1 agent
`T2 agent
`Non toxic
`Imaging vascular
`compartment at early phase
`(as a bolus administration)
`and at a late stage
`(equilibrium phase)
`Multiple administration in
`single examination
`Image of multiple target
`organs
`Bolus injection
`
`Yes
`
`Yes
`
`Yes
`No
`Yes
`No
`
`No
`
`Yes
`
`Yes
`
`No
`
`No
`
`Sometimes
`Yes
`No
`No
`
`No
`
`Sometimes
`
`No
`
`TABLE 1-continued
`
`Comparison of ideal properties of MRI contrast agents With properties of
`lOW molecular Weight gadolinium based contrast agents and colloidal iron
`oxides.
`
`Properties of an ideal
`contrast agent
`
`lOW molecular Weight
`gadolinium
`
`colloidal iron
`oxides
`
`LoW volume of injection
`Iron source for anemia
`
`No
`No
`
`No
`Yes
`
`SUMMARY OF THE INVENTION
`
`[0004] An embodiment in accordance With the presently
`claimed invention includes an improved method for admin
`istration of a pharmacological composition of the type
`employing an iron oxide complex With a polyol or polyether,
`Wherein the improvement comprises administering parenter
`ally an effective dose of an iron oxide complex With a polyol
`or polyether, the complex formulated in a biocompatible
`liquid so that upon administration the complex provides
`minimal detectable free iron in a subject and minimal
`incidence of anaphylaxis, and effecting such administration
`at a rate substantially greater than 1 mL/min or alternatively,
`the administration may be at a rate of about 1 mL/sec.
`
`[0005] We have found it possible to formulate complexes
`having the properties described above. Whereas prior art
`complexes of dextran and iron oxide can be made that have
`minimal detectable free iron, and other complexes of iron
`oxide may have minimal incidence of anaphylaxis, no prior
`art complexes of iron oxide have both properties. We have
`surprisingly found a Way of providing a complex of modi
`?ed polyols or polyethers With iron oxide that have both
`properties. We have found, for example, that a polysaccha
`ride such as dextran, When reduced and carboxyalkylated,
`can be complexed With iron oxide to produce a composition
`that continues (like dextran iron oxide) to have minimal
`detectable free iron in a subject, While (unlike dextran iron
`oxide) also having minimal incidence of anaphylaxis.
`
`[0006] Another embodiment of the present invention
`includes an improved method for administration of a phar
`macological composition of the type employing an autocla
`vable reduced carboxyalkylated polysaccharide iron oxide
`complex With a polyol or polyether, Wherein the improve
`ment comprises administering parenterally an effective dose
`of an iron oxide complex, the complex formulated in a
`biocompatible liquid so that upon administration the com
`plex provides minimal detectable free iron in a subject, and
`minimal incidence of anaphylaxis, and effecting such
`administration at a rate substantially greater than 1 mL/min
`or alternatively, a rate of about 1 mL/sec.
`
`[0007] A particular embodiment of the presently claimed
`invention includes an improved method for administration
`of a pharmacological composition of the type employing an
`iron oxide complex With a polyol or polyether, Wherein the
`improvement comprises parenteral administration of the
`complex to provide minimal detectable free iron in a subject
`as measured by a catalytic bleomycin assay and minimal
`incidence of anaphylaxis.
`
`[0008] Another particular embodiment includes an
`improved method for administration of a pharmacological
`
`Pharmacosmos, Exh. 1003, p. 15
`
`

`

`US 2003/0232084 A1
`
`Dec. 18, 2003
`
`composition of the type employing an iron oxide complex
`With a polyol, for example dextran, or polyether, for example
`polyethylene glycol, Wherein the improvement further com
`prises parenteral administration of the complex to provide
`minimal dissolution of the complex in a human subject
`measured as a function of transferrin saturation in vivo.
`
`[0009] Still another particular embodiment provides an
`improved method for administration of a pharmacological
`composition of the type employing an iron oxide complex
`With a polyol or polyether, Wherein the improvement further
`comprises parenteral administration of the complex to pro
`vide the polyol or polyether complex as an immunosilent
`complex in a human subject.
`
`[0010] Another particular embodiment in accordance With
`the present invention includes an improved pharmacological
`composition of the type employing an iron oxide complex
`With a polyol or polyether, Wherein the improvement com
`prises formulating a polyol or polyether complexation With
`iron oxide to provide upon administration to a subject
`minimal detectable free iron in the subject as measured by
`a catalytic bleomycin assay and minimal incidence of ana
`phylaxis.
`[0011] Yet another embodiment in accordance With the
`present invention is an improved pharmacological compo
`sition of the type employing an iron oxide complex With a
`polyol or polyether, Wherein the improvement comprises
`formulating a polyol or polyether complex With the iron
`oxide to provide upon administration to a subject minimal
`dissolution of the complex in the subject, measured as a
`function of transferrin saturation in vivo.
`
`[0012] Other embodiments include an improved pharma
`cological composition of the type employing an iron oxide
`complex With a polyol or polyether, Wherein the improve
`ment comprises formulating a polyol or polyether complex
`ation With iron oxide to provide upon administration to a
`subject the iron oxide complex as an immunosilent complex
`in a human subject.
`
`[0013] Another embodiment in accordance With the
`present invention includes an improved method for admin
`istration of a pharmacological composition of the type
`employing an iron oxide complex With a polyol or polyether,
`Wherein the improvement comprises parenteral administra
`tion of an effective dose of the complex formulated in a
`biocompatible liquid delivered at a rate substantially greater
`than 1 mL/min and Wherein upon administration the com
`plex provides minimal detectable free iron in a subject, and
`minimal incidence of anaphylaxis; or alternatively, the com
`plex is delivered at a rate of about 1 mL/sec. More particu
`larly, the improved method may utiliZe an assay for deter
`mining minimal detectable free iron Wherein the assay is any
`assay knoWn in the art for measuring free iron concentration,
`including a BDI assay, atomic absorption spectroscopy, a %
`transferrin saturation assay, a % dialysis assay, and a bac
`terial groWth assay. Still more particularly, the assay for
`determining minimal incidence of anaphylaxis is an ELISA
`assay.
`
`[0014] In other embodiments in accordance With the
`invention includes an improved method for administering a
`pharmacological composition of the type employing an iron
`oxide complex With a polyol or polyether, Wherein the
`improvement comprises parenteral administration of an
`
`effective dose of the complex formulated in a biocompatible
`liquid delivered at a rate substantially greater than 1
`mL/min, or alternatively at about 1 mL/sec, and Wherein
`upon administration the complex provides minimal detect
`able free iron in a subject and minimal incidence of ana
`phylaxis, and Wherein the free iron concentration is deter
`mined using a BDI assay, and is less than about 750 nM, or
`less than about 0.04 pg/mL, or less than about 0.1% of the
`effective dose of iron oxide, depending upon hoW the
`BDI-detected free iron measurement is reported. In alterna
`tive embodiments, the free iron concentration is determined
`using atomic absorption spectroscopy, and is less than about
`1 ppm or less than about 0.04 pg/mL, or less than about 0.1%
`of the effective dose of the iron oxide, depending upon hoW
`the atomic absorption-detected free iron measurement is
`reported; or, the free iron concentration is determined using
`a iron dialyZed % assay, and the dialyZed-determined free
`iron percent is less than about 1%.
`[0015] Yet another embodiment of the present invention
`includes an improved method for administration of a phar
`macological composition of the type employing an iron
`oxide complex With a polyol or polyether, Wherein the
`improvement comprises parenteral administration of an
`effective dose of the complex formulated in a biocompatible
`liquid delivered at a rate substantially greater than 1
`mL/min, or alternatively at a rate of about 1 mL/sec, and
`Wherein upon administration the complex provides minimal
`detectable free iron in a subject and minimal incidence of
`anaphylaxis, and Wherein the improvement further com
`prises parenteral administration of the complex to provide
`minimal dissolution of the complex in a human subject.
`More particularly, in alternative embodiment, the minimal
`dissolution of the complex is determined using a % trans
`ferrin saturation assay; and more particularly, the minimal
`dissolution of the complex determined by a % transferrin
`saturation assay is less than about 95% saturation for a total
`dose from about 1 mg/kg of body Weight to about 4 mg/kg
`of body Weight, up to a total single dose of about 500 mg to
`about 600. An alternative embodiment further comprises
`parenteral administration of the complex to provide the iron
`oxide complex as a substantially immunosilent complex in
`a human subject. In such embodiments, veri?cation of
`administration that provides a complex that is substantially
`immunosilent in a human complex may be determined by a
`guinea pig anaphylaxis test.
`[0016] Other embodiments in accordance With the present
`invention include an improved pharmacological composi
`tion of the type employing an iron oxide complex With a
`polyol or polyether, Wherein the improvement comprises a
`polyol or polyether iron oxide complex composition pre
`pared at concentrations of betWeen about 1 mg/kg of body
`Weight to about 4 mg/kg of body Weight in a total volume of
`biocompatible liquid from about 1 mL to about 15 mL and
`for a total single dose from about 50 mg to about 600 mg,
`Wherein the pharmacological composition is capable of
`being parenterally administered to a subject at a rate sub
`stantially greater than 1 mL/min, or alternatively at a rate of
`about 1 mL/sec, and Wherein the iron oxide complex pro
`vides upon administration minimal detectable free iron in
`the subject and minimal incidence of anaphylaxis. More
`particularly, the improved pharmacological composition
`may further comprise an iron oxide complex having minimal
`free iron concentration in the subject. Determination of
`minimal free iron can be measured using any standard assay
`
`Pharmacosmos, Exh. 1003, p. 16
`
`

`

`US 2003/0232084 A1
`
`Dec. 18, 2003
`
`for measuring free iron known in the art, including a BDI
`assay, atomic absorption spectroscopy, a % transferrin satu
`ration assay, a % dialysis assay, or a bacterial groWth assay.
`Alternatively, the improved pharmacological composition
`may further comprise an iron oxide complex that undergoes
`minimal dissolution in a human subject upon administration
`to the subject. Other alternatives envision that the improved
`pharmacological composition may further comprise an iron
`oxide complex that undergoes minimal dissolution upon
`administration in a human subject. Minimal dissolution may
`be determined using a % transferrin saturation assay. Alter
`natively, the improved pharmacological composition may
`further comprise an iron oxide complex that is substantially
`immunosilent upon administration in a human subject, and
`particularly, the improved pharmacological composition
`may further comprise an iron oxide complex that is sub
`stantially immunosilent in a human subject as determined by
`a guinea pig anaphylaxis test.
`
`[0017] Yet another embodiment in accordance With the
`present invention includes a method of treating a subject
`With an iron oxide complex to a subject in need thereof, the
`method comprising parenterally administering the complex
`formulated in a pharmaceutically acceptable formulation in
`a biocompatible liquid, effecting administration at a rate
`substantially greater than 1 mL/min, and providing an effec
`tive dose in the range of about 1 mg/kg of body Weight to
`about 4 mg/kg of body Weight in a total volume of biocom
`patible liquid of betWeen about 1 mL and 15 mL so that
`minimal free iron and minimal anaphylaxis occurs. More
`particularly, the method may comprise effecting administra
`tion at a rate of betWeen about 180 pL/sec and about 1
`mL/min. Still more particularly, the administration of the
`iron oxide complex provides minimal dissolution of the
`complex in the subject and may further provide a substan
`tially immunosilent complex to the subject. More particu
`larly, a guinea pig test may be used to determine that the
`complex administered in the above method for treating is
`substantially immunosilent to the subject.
`
`[0018] Another embodiment of the invention includes a
`method of treating a subject With an autoclavable reduced
`carboxyalkylated polyol, for example dextran, iron oxide
`complex having at least 750 but less than 1500 pmole of
`carboxyalkyl groups per gram of polyol to a subject, the
`method comprising parenterally administering the complex
`formulated in a pharmaceutically acceptable formulation in
`a biocompatible liquid, effecting administration at a rate
`substantially greater than 1 mL/min, and providing an effec
`tive dose in the range of about 1 mg/kg of body Weight to
`about 4 mg/kg of body Weight in a total volume of biocom
`patible liquid of betWeen about 1 mL and 15 mL so that
`minimal free iron and minimal anaphylaxis occurs.
`
`[0019] Yet another embodiment includes an improved
`pharmacological composition of the type employing an
`autoclavable carboxyalkylated polyether iron oxide com
`plex, for example polyethylene glycol, Wherein the improve
`ment comprises a carboxyalkylated iron oxide complex
`composition having at least 250 pmole but less than 1500
`pmole of carboxyalkyl groups per gram of polyether, pre
`pared at concentrations of betWeen about 1 mg/kg of body
`Weight to about 4 mg/kg of body Weight in a total volume of
`biocompatible liquid from about 1 mL to about 15 mL and
`for a total single dose from about 50 mg to about 600 mg,
`Wherein the pharmacological composition is capable of
`
`being parenterally administered to a subject at a rate sub
`stantially greater than 1 mL/min and Wherein the iron oxide
`complex provides upon administration minimal detectable
`free iron in the subject and minimal incidence of anaphy
`laxis.
`
`[0020] Another embodiment of the invention is a method
`of providing an iron oxide complex for administration to a
`mammal subject, the method comprising: producing a
`reduced polysaccharide iron oxide complex, and steriliZing
`the complex by autoclaving. In general, the reduced polysac
`charide is a reduced polymer of glucose. An example of a
`reduced polymer of glucose is a reduced dextran. The
`reduced polysaccharide is produced through reaction of a
`polysaccharide With a reagent selected from the group
`consisting of a borohydride salt or hydrogen in the presence
`of a hydrogenation catalyst. In a further aspect of the
`method, the iron oxide is superparamagnetic.
`
`[0021] Another particular embodiment of the invention is
`a method of providing an iron oxide complex for adminis
`tration to a mammalian subject, the method comprising:
`producing a derivatiZed reduced polysaccharide iron oxide
`complex, and steriliZing the complex by autoclaving.
`According to this method, producing the complex can
`include derivatiZing a reduced polysaccharide by formation
`of, for example, ethers, amides, esters, and amines at the
`hydroxyl positions of the polysaccharide. In a particular
`embodiment, the derivative formed is an ether of the
`polysaccharide, more particularly a carboxyalkyl ether of
`the polysaccharide, and more particularly, a carboxymethyl
`ether of the polysaccharide. Further according to this
`method, the reduced polysaccharide can be a reduced dex
`tran. The derivatiZed, reduced polysaccharide can be iso
`lated as the sodium salt and does not contain an infrared
`absorption peak in the region of 1650-1800 cm_1. In one
`aspect of the method, producing the derivatiZed reduced
`polysaccharide is achieved at a temperature of less than
`approximately 50° C. In another aspect of the method,
`producing the derivatiZed reduced polysaccharide is
`achieved at a temperature of less than approximately 40° C.
`In a further aspect of the method, the iron oxide is super
`paramagnetic.
`[0022] In yet another embodiment, the invention provides
`a method of formulating an iron oxide complex coated With
`a reduced polysaccharide. This composition is for pharma
`cological use and the composition has decreased toxicity in
`comparison to a formulation of an iron oxide complex
`coated With the non-reduced polysaccharide. The method of
`formulating such an iron oxide complex comprises: produc
`ing a reduced polysaccharide iron oxide complex, and
`steriliZing the complex by autoclaving. The formulation
`provides a polysaccharide Which Was produced by reacting
`the polysaccharide With one of a reducing agent selected
`from the group consisting of a borohydride salt or hydrogen
`in the presence of an hydrogenation catalyst, Wherein the
`reduced polysaccharide iron oxide complex so made has
`such decreased toxicity. In a further aspect of the method,
`the iron oxide is superparamagnetic.
`
`[0023] In yet another embodiment, the invention provides
`a method of formulating an iron oxide complex coated With
`a reduced derivatiZed polysaccharide. This composition is
`for pharmacological use and the composition has decreased
`toxicity in comparison to a formulation of an iron oxide
`
`Pharmacosmos, Exh. 1003, p. 17
`
`

`

`US 2003/0232084 A1
`
`Dec. 18, 2003
`
`complex coated With the non-reduced derivatiZed polysac
`charide. The method of formulating such an iron oxide
`complex comprises: producing a reduced derivatiZed
`polysaccharide iron oxide complex; and sterilizing the com
`plex by autoclaving. According to this method, producing
`the complex can include derivatiZing a reduced polysaccha
`ride by carboxyalkylation, for example, Wherein the car
`boxyalkylation is a carboxymethylation. Further according
`to this method, the reduced polysaccharide can be a reduced
`dextran. The derivatiZed, reduced polysaccharide can be
`isolated as the sodium salt and does not contain an infrared
`absorption peak in the region of 1650-1800 cm_1. In one
`aspect of the method, producing the derivatiZed reduced
`polysaccharide is achieved at a temperature of less than
`approximately 50° C. In another aspect of the method,
`producing the derivatiZed reduced polysaccharide is
`achieved at a temperature of less than approximately 40° C.
`In a further aspect of the method, the iron oxide is super
`paramagnetic.
`[0024] Another embodiment of the invention provides a
`reduced derivatiZed polysaccharide iron oxide complex With
`T1 and T2 relaxation properties to alloW contrast agent
`signal enhancement With T1 sequences and signal dimin
`ishment With T2 sequences. A further aspect of the embodi
`ment is that the reduced derivatiZed polysaccharide iron
`oxide can be administered multiple times for sequential
`imaging in a single examination. Yet another aspect of the
`agent is that it can be used to image multiple organ systems
`including the vascular system, liver, spleen, bone marroW,
`and lymph nodes.
`
`[0025] Another embodiment of the invention provides a
`reduced polysaccharide iron oxide complex for use as an
`intravenous iron supplement.
`
`[0026] Another embodiment of the invention provides a
`reduced derivatiZed polysaccharide iron oxide complex for
`use as an intravenous iron supplement.
`
`[0027] In yet a further embodiment, the invention provides
`an improved method of administering to a mammalian
`subject an autoclaved reduced polysaccharide iron oxide
`complex. The improved method of administration compris
`ing: injection of an autoclaved reduced polysaccharide iron
`oxide complex in a volume of 15 mL or less. In another
`aspect of the embodiment the injected volume is injected as
`a bolus. In a further aspect of the method, the iron oxide is
`superparamagnetic. In a further aspect of the embodiment
`the injected volume provides improved image quality.
`
`[0028] In yet a further embodiment, the invention provides
`an improved method of administering to a mammalian
`subject an autoclaved derivatiZed reduced polysaccharide
`iron oxide complex, the improved method of administration
`comprising: injection of an autoclaved reduced derivatiZed
`polysaccharide iron oxide complex in a volume of 15 mL or
`less. In another aspect of the embodiment the injected
`volume is injected as a bolus. In a further aspect of the
`method, the iron oxide is superparamagnetic. In a further
`aspect of the embodiment the injected volume provides
`improved image quality.
`[0029] An embodiment of the invention provides an
`improved method of administering to a mammalian subject
`a reduced polysaccharide iron complex to a mammalian
`subject Wherein the improvement comprises administration
`
`of a reduced polysaccharide in formulation to provide
`reduced toxicity relative to administration of a non-reduced
`polysaccharide. In a further aspect of the embodiment, the
`iron oxide is superparamagnetic.
`
`[0030] An embodiment of the invention provides an
`improved method of administering to a mammalian subject
`a reduced derivatiZed polysaccharide iron complex in a
`manner that the composition provides reduced toxicity,
`Wherein the improvement comprises utiliZing a reduced
`derivatiZed polysaccharide in formulation of the composi
`tion. In a further aspect of the embodiment, the iron oxide is
`superparamagnetic.
`[0031] An embodiment of the invention provides a
`reduced polysaccharide iron oxide complex, Wherein the
`reduced polysaccharide is derivatiZed, for example, the
`reduced derivatiZed polysaccharide is a carboxyalkyl
`polysaccharide. The carboxyalkyl is selected from the group
`consisting of carboxymethyl, carboxyethyl and carboxypro
`pyl. Further, the reduced polysaccharide can be a reduced
`dextran, for example, the reduced dextran can be a reduced
`carboxymethyl dextran. Afurther aspect of this embodiment
`of the invention is that the level of derivatiZation of the
`reduced dextran is at least 750 pmole but less than 1500
`pmole of carboxyl groups per gram of polysaccharide
`Wherein said composition has reduced toxicity relative to
`composition With respect to loWer levels of derivatiZation.
`
`[0032] An embodiment of the invention provides a
`reduced polysaccharide iron oxide complex, such complex
`being stable at a temperature of at least approximately 100°
`C. In a preferred embodiment, such complex is stable at a
`temperature of approximately 121° C. In an even more
`preferred aspect of the reduced polysaccharide iron oxide
`complex, such complex is stable at a temperature of at least
`121° C. for a time sufficient to steriliZe the complex. In a
`further aspect of the embodiment, the iron oxide is super
`paramagnetic.
`[0033] An embodiment of the invention provides a
`reduced derivatiZed polysaccharide iron oxide complex,
`such complex being stable at a temperature of at least
`approximately 100° C. In a preferred embodiment, such
`complex is stable at a temperature of approximately 121° C.
`In an even more preferred aspect of the reduced polysac
`charide iron oxide complex, such complex is stable at a
`temperature of at least 121° C. for a time sufficient to
`steriliZe the complex. In a further aspect of the embodiment,
`the iron oxide is superparamagnetic.
`
`[0034] A particular embodiment of the invention is a
`method of formulating for pharmacological use a reduced
`polysaccharide iron oxide complex having increased pH
`stability in comparison to the corresponding native dextran
`iron oxide, the method comprising: providing dextran, and
`reacting the dextran With a borohydride salt or hydrogen in
`the presence of an hydrogenation catalyst, reacting the
`reduced dextran With iron salts to provide a formulation
`having a stable pH.
`
`[0035] A particular embodiment of the invention is a
`method of formulating for pharmacological use a reduced
`derivatiZed polysaccharide iron oxide complex having
`increased pH stability in comparison to the corresponding
`native dextran iron oxide, the method comprising: providing
`dextran; and reacting the dextran With a borohydride salt or
`
`Pharmacosmos, Exh. 1003, p. 18
`
`

`

`US 2003/0232084 A1
`
`Dec. 18, 2003
`
`hydrogen in the presence of an hydrogenation catalyst,
`reacting the reduced dextran With iron salts to provide a
`formulation having a stable pH.
`
`[0036] In another embodiment, the invention provides a
`method of formulating a reduced derivatiZed dextran com
`position for pharmacological use Wherein the composition
`has decreased toxicity in comparison to native dextran,
`comprising: producing a reduced derivatiZed polysaccha
`ride; and steriliZing the product by autoclaving. According
`to this method, the reduced polysaccharide is obtained by
`reacting the native polysaccharide With one of several reduc
`ing agents selected from the group consisting of a borohy
`dride salt or hydrogen in the presence of a hydrogenation
`catalyst. In a preferred aspect of the embodiment the
`polysaccharide is dextran. Producing the composition can
`include derivatiZing a reduced polysaccharide by carboxy
`alkylation, for example, Wherein the carboxyalkylation is a
`carboxymethylation. Further according to this method, the
`reduced polysaccharide can be a reduced dextran. The
`derivatiZed, reduced polysaccharide can be isolated as the
`sodium salt and does not contain an infrared absorption peak
`in the region of 1650-1800 cm_1. In one aspect of the
`method, producing the derivatiZed reduced polysaccharide is
`achieved at a temperature of less than approximately 50° C.
`In another aspect of