Iron complexes citrates

A number of water-soluble calcium salts provide convenient vehicles for the administration of therapeutic anions. Probably the most widely encountered is the acetylsalicylate of soluble aspirin (patented 1935) the urea complex of calcium acetylsalicylate (water-solubility 231 gdm-3 at 310K, pH 4.8 (717)) is also widely used. Other examples include calcium bromide and bromolactobionate (sedatives), calcium 2-hydroxy-3-mercapto-l-propanesulfonateaurate(III) (chrysanol, antiarthritic), and calcium Af-carbamoylaspartate (tranquillizer). Calcium iron(II) citrate has been used to remedy iron deficiency - it has the advantage of being stable to air oxidation of the iron(II). The cyclamate anion is certainly not therapeutic, but is relevant here. 

Iron(III) citrate, " " or iron(III) ammonium citrate, is the usual vehicle for administering supplementary iron to an iron-deficient patient, for inducing iron-overload in rats or other creatures prior to testing the efficacy of iron chelators, or for introducing the isotope Fe for metabolic tracer studies. Stability constants for the aqueous iron(III)-citrate system have been established. " The 2 1 complex is claimed to be the dominant species in iron(III)/citrate/DMF systems. " There has been a very qualitative study of the incorporation of iron into transferrin from iron citrate. " Iron(III) citrate reacts relatively slowly with the aluminum(III)-transferrin complex to give the thermodynamically strongly favored combination of iron(III)-transferrin with aluminum(lll) citrate. " The mechanism of iron uptake from citrate complexes in cells has been briefly discussed. An octa-iron citrate complex appears in Section 5.4.5.4.3 below. 

Other forms of iron which are present in different pharmaceutical preparations are ferric ammonium citrate, ferrous succinate, iron choline citrate, ferrous amionate, iron calcium complex, carbonyl iron, ferric glycerophosphate, haemoglobin, elemental iron, ferrous glycine sulphate, glycerinated haemoglobin, and iron (III) hydroxide polymaltose complex (equivalent to elemental iron). 

Warner and Weber (133), Davis et al. (32), and A as a et al. (1) have studied the dissociation constants of the iron and copper complexes of human serum transferrin and chicken ovotransferrin. Assignment of the dissociation constants requires interpretation of the relationships between the two metal ions bound. These relationships will be discussed below. Warner and Weber (133) calculated approximate values of 10-17 and 10 29 for the dissociation constants of the copper and iron complexes, respectively. These constants were obtained in competition with citrate ion. Approximately similar values for iron in human serum transferrin of 10 28 for the first iron and of 10 30 for the second iron were reported by Davis et al. (32). 

Starch-iron complexes are reported as biologically active sources of iron.627 628 In one report, it is warned that such complexes may produce sarcomas as a result of long-term exposure.629 Investigations630 have shown that, independently of the ferric salt used, the maximum capacity of the salt in starch is 2-7 mg%. Because pH 5.8 is more conducive to stability than low pH values (3 or lower), higher concentrations of ferric salt are not advisable. Shi Decheng631 recommended blending starch (100 g) with trisodium citrate (25g) and 2 M FeCl3 (500 mL) in water (2500 mL) at... 

Iron(II) and iron(III) citrates are known but have a poorly defined composition, though octa-iron and nona-iron citrate complexes have been characterized in solution, complex species exist. Brown and green hydrated iron(III)... 

SYNS CHELAFER CHEL-IRON FERRIC CHOLINE CITRATE FERROLIP IRON CHOLINE CITRATE COMPLEX... 

The photoreduction of xylem-transported ferric carboxylates, like citrate, is thought to be an important driving force in the reduction of iron in shoots thereafter, the distribution of iron to the leaves is probably mediated again by the NA-iron complex (Fig. 8.9). 

Too high concentrations of the active compound at the injection site (initial peak concentrations) are avoided in masking the irritating agent through complexation. The free concentrations of iron or of calcium are reduced in using calcium gluconate or levulinate for intravenous injections and iron-sorbitol citrate for intramuscular injections. ... 

Gautier-Luneau, L, Merle, C., Phanon, D.. Lebrun, C., Biaso. F., Serratrice, G.. and PieiTe. J.-L. (2005). New trends in the chemistry of iron(in) citrate complexes coiTelations between x-ray structure and solution species probed by electrospray mass spectrometry and kinetics of iron uptake from citrate by iron chelators. Chem. Eur. J. 11, 2207-2219. 

Shweky, I., Bino, A., Goldberg, D. P., and Lippard, J. (1994). Synthesis, structures, and magnetic properties of two dinuclear iron(ni) citrate complexes. Inorg. Chem. 33, 5161-5162. 

The most time-honored and certainly dependable method for serum, urine, and tissue copper determination is that described by Eden and Green in 1940 (E3). Wet ashing with a combination of sulfuric, perchloric, and nitric acids is followed by the deionization of iron with citrate and/or pyrophosphate in strongly alkaline medium. Diethyldithiocarbamate is the color reagent and the complex is extracted into amyl alcohol. Provided blanks can be kept low, which can be achieved only by applying extreme care to avoid contamination of the many reagents, copper can be determined reliably in 0.5-1.0 ml of serum. While this method undoubtedly represents a great improvement over previous methods (M4, T5), it is somewhat cumbersome nevertheless it has proved its worth in many hands and has been the basis of a number of modifications and applications. 

Another way to slow substitution is to covalently bond a ligand to silica— compare bonding ligands to monoclonal antibodies above. Oxine bound to silica reacts much more slowly with Al, for example, than when it is in solution. Another example of slow substitution at Al is related to the indium chemistry mentioned above, involving its slow transfer from its transferrin complex by reaction with iron(III)-citrate to form the much more stable combination of iron-transferrin and aluminum-citrate complexes. Further examples of slow substitution kinetics involving ferritin will be found in the iron(III) section (Section 8.3.4). 

Synonyms Ferrocholinate Iron (III) choline citrate Iron choline citrate complex... 

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