Calcium iron citrate

Calcium, iron, magnesium, alkali metals, and citrates do not affect the analysis. Ammonium salts interfere and must be eliminated by means of sodium nitrite or sodium hypobromite. The hydrochloric acid normally used in the analysis may be replaced by an equivalent amount of nitric acid without any influence on the course of the reaction. Sulphuric acid leads to high and erratic results and its use should be avoided. 

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. 

Difficulty to measure very low solubilities is clearly iUustrated in the case of dissolution of calcium citrate at 25 °C in pure water (Fig. 5.1). The scattering of experimental solubilities for more soluble magnesium and iron citrates is less pronounced (Fig. 5.2). From similar investigations, it is worthwhile to mention also the Bolton [138] detailed solubility study in systems included tiisodiumcitrate, acetylsalicyUc acid (aspirin) and benzoic acid. 

Wilson critically surveyed the present methods of determining P2O5 and has shown that by precipitating as quinoline phosphomolybdate and completing volumetrically, accurate results can be obtained. Calcium, iron, magnesium, alkali metals, citrates and nitrates do not interfere but ammonium salts must be destroyed and a high concentration of sulphuric acid must be avoided. 

Once in the serum, aluminium can be transported bound to transferrin, and also to albumin and low-molecular ligands such as citrate. However, the transferrrin-aluminium complex will be able to enter cells via the transferrin-transferrin-receptor pathway (see Chapter 8). Within the acidic environment of the endosome, we assume that aluminium would be released from transferrin, but how it exits from this compartment remains unknown. Once in the cytosol of the cell, aluminium is unlikely to be readily incorporated into the iron storage protein ferritin, since this requires redox cycling between Fe2+ and Fe3+ (see Chapter 19). Studies of the subcellular distribution of aluminium in various cell lines and animal models have shown that the majority accumulates in the mitochondria, where it can interfere with calcium homeostasis. Once in the circulation, there seems little doubt that aluminium can cross the blood-brain barrier. 

The most direct evidence for surface precursor complex formation prior to electron transfer comes from a study of photoreduc-tive dissolution of iron oxide particles by citrate (37). Citrate adsorbs to iron oxide surface sites under dark conditions, but reduces surface sites at an appreciable rate only under illumination. Thus, citrate surface coverage can be measured in the dark, then correlated with rates of reductive dissolution under illumination. Results show that initial dissolution rates are directly related to the amount of surface bound citrate (37). Adsorption of calcium and phosphate has been found to inhibit reductive dissolution of manganese oxide by hydroquinone (33). The most likely explanation is that adsorbed calcium or phosphate molecules block inner-sphere complex formation between metal oxide surface sites and hydroquinone. 

Drugs that may affect tetracyclines include antacids containing aluminum, calcium, or magnesium iron salts zinc salts barbiturates bismuth salts carbamazepine cholestyramine colestipol phenytoin rifamycins urinary alkalinizers (eg, sodium lactate, potassium citrate). 

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). 

There is a close relationship between the metabolism of the shoot and the root. It is generally accepted that the xylem forms the main path for upward movement of water and ions from the roots to the leaves. Most of the essential major elements are transported in the xylem as inorganic ions. Nitrogen may be transported along the xylem as N03 if it is present in the external solution as nitrate. However, the plant sap may also contain organic nitrogen compounds such as amino acids. In the xylem, heavy metals will usually only be transported if special chelates are formed, eg, by citrate (Streit and Stumm, 1993). Iron is taken up and transported more readily when supplied as a chelated complex, such as ferric ethylenediamine tetraacetate (FeEDTA) or as ferric diethylenetriamine pentaacetate (FeDTPA) (Wallace and North, 1953). Calcium may also be transported in a chelated form (Jacoby, 1966). 

The chemicals used in this study were sodium chloride, magnesium chloride, calcium chloride, potassium chloride, trichloroacetic acid (TCA), trifluoroacetic acid, a-d glucose, sodium citrate dihydrate, sodium hydrogen phosphate, hydrochloric acid, and iron (11) sulfote heptahydrate. These chemicals were purchased from Sigma (St. Louis, MO, USA). The HPLC grade solvent, acetonitrile was fivm J. T. Baker (Philipsburg NJ, USA). Water was distilled and deionized prior to use. 

Binding of iron by dietary fiber is strongly inhibited by ascorbic acid, citrate, cysteine, EDTA or phytate in concentrations as lew as 100 >uMols/Liter (A3). The inhibitors have the common property of being able to form soluble complexes with iron. The decarbox-ylic amino acids and their amides inhibit binding moderately as do lysine and histidine. Other amino acids either do not interfere with binding of iron fiber or do so only weakly. Calcium (as acetate) and phosphate act as moderate inhibitors. The detergents sodium lauryl sulfonate or cetyltrimethylammonium bromide had no effect on iron binding by fiber (A2). 

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. ... 

Ferrous sulfate (20% elemental iron) and ferrous gluconate (11.6% elemental iron) are used in iron deficiency anemia. Extensive numbers of oral preparations are available for the treatment of iron deficiency. In general, the ferrous salts (ferrous sulfate, ferrous gluconate, and ferrous fumerate) are better absorbed than the ferric salts (ferric sulfate). Eerrous calcium citrate is mostly used in patients during pregnancy to provide iron as well as calcium. The parenteral... 

These experimental data are well-described by first-order kinetics, with best-fit half-lives of 6.7, 3.4, and 0.4 h for 0.01 M phosphate, 0.1 M phosphate, and 0.01 M sodium citrate buffers, respectively. These purified buffers may lack essential eo-factors that could stabilize the rMnP, such as calcium, manganese, and iron. As Ca ion is essential for MnP activity, chelation of calcium ions by citrate (and to a lesser extent, phosphate) is probably the mechanism for the observed first-order kinetics of inactivation in these buffers. These attempts to determine the effect of pH on rMnP activity in defined buffers were ultimately deemed unsuecessful, as the rates of inactivation in potassium phosphate (0.1 and 0.01 M) and sodium citrate (0.01 M) buffers were observed to be considerably higher than in the bioreactor culture supernatant. 

The results of dietary zinc analysis need to be considered in terms of the availability of the zinc in the food for intestinal absorption. The zinc content of whole meals and the total daily zinc intake are not sufficient information on their own, without knowledge of factors which inhibit or promote intestinal absorption (O Dell, 1984). Free ionic zinc probably does not exist in the intestinal tract, zinc being bound to molecular species such as protein, amino acids, phytic acid, citrate and others. The bioavailability of the metal is determined by the nature of these zinc binding ligands. When the zinc complex is insolubie as in Zn-phytate, the uptake from diet is poor, whereas zinc-protein or zinc-amino acid complexes are more easily dissociated and are a good source of available zinc. Other dietary components affect zinc absorption such as the amount of iron, calcium and phosphate. 

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