Iron (III) hydroxide complexes with activated glucose syrups and process for preparing same
20170232040 · 2017-08-17
Inventors
Cpc classification
A61K31/7004
HUMAN NECESSITIES
A61K47/69
HUMAN NECESSITIES
International classification
Abstract
The present invention generally relates to iron (III) carbohydrate complexes and to processes for the manufacture thereof. The product obtainable according to the method of the present invention may be safely used to the general population or animals in the therapy of iron deficiency. The process of the invention includes the steps of (i) providing an aqueous solution of glucose syrup having a certain dextrose equivalent (DE), (ii) adding one or more oxidizing bleaching agents, thereby obtaining the activated glucose syrup; (iii) converting said activated glucose syrup into a complex with iron (III) hydroxide; and (iv) obtaining a complex of iron (III) hydroxide and activated glucose syrup.
Claims
1-9. (canceled)
10. Process for the preparation of complexes of iron (Iii) hydroxide and activated glucose syrup, wherein the molecular weight of the complex is in the range of from 100 kDa to 150 kDa, as measured by high performance liquid chromatography-gel permeation chromatography (HPLC-GPC), said process comprising the steps: (i) providing an aqueous solution of glucose syrup, having a dextrose equivalent (DE) of at least 21 and at most 60, as determined by gravimetrical analysis, at a temperature in the range of from 25° C. to 80° C. and at a pH in the range of from 6 to 13; (ii) adding hydrogen peroxide, and optionally a catalytic amount of an oxidation catalyst, to the solution of (i), while maintaining the pH and temperature within the range as defined in step (i), allowing the solution to cool down to a temperature in the range of from 10° C. to 45° C., keeping the solution at this temperature for 5 min to 24 hours, thereby obtaining the activated glucose syrup; (iii) converting said activated glucose syrup into a complex with iron (III) hydroxide; and (iv) obtaining a complex of iron (III) hydroxide and activated glucose syrup, wherein the hydrogen peroxide is used in a total amount of 0.0005-0.01 mol/g (glucose syrup) multiplied with the correction factor: (dextrose equivalent of the glucose syrup)/21, wherein the complex has an iron content in the range of from 27 to 35 wt. %, based on the weight of the complex; and wherein the obtained complex of iron (III) hydroxide and activated glucose syrup has more than two —COOH groups per glucose molecule and wherein the glucose syrup of step (i) does not have any —COOH group at the glucose molecule.
11. The process of claim 10, wherein the dextrose equivalent (DE) of the activated glucose syrup is in the range of from 0.1 to 1.0 and/or the obtained complex of iron (III) hydroxide and activated glucose syrup has at least three —COOH groups per glucose molecule, which indicates that the glucose syrup is activated.
12. The process of claim 10, wherein the step of converting said activated glucose syrup into a complex with iron (III) hydroxide comprises the steps of: (iii)(a) adding a solution of FeCl.sub.3 to the solution of (ii) at a temperature within the range of from 10 to 30° C.; the amount of FeCl.sub.3 is in the range of from 30% wt.-% to 120% wt.-% of the amount of glucose syrup; (iii)(b) adding an inorganic base to the reaction mixture of step (iii)(a) until the pH is within a range of from 1.5 to 2.5; and (iii)(c) heating the reaction mixture of step (iii)(b) to a temperature within the range of from 40 to 60° C.
13. The process of claim 10, wherein the oxidation catalyst includes bromine and iodine ions.
14. Complex of iron (III) hydroxide and glucose syrup obtainable or obtained by the process of claim 10.
15. Pharmaceutical composition comprising the complex of claim 14.
16. Complex of claim 14 for use as medicament.
17. Complex of claim 14 for use in a method of treating iron deficiency in human and animal.
18. The complex or pharmaceutical composition for use according to claim 17, wherein the treatment comprises parenterally administering said complex of claim 14.
19. The complex or pharmaceutical composition for use according to claim 17, wherein the treatment comprises parenterally administering said pharmaceutical composition of claim 15.
20. The process of claim 11, wherein the dextrose equivalent (DE) of the activated glucose syrup is about 0.3.
Description
DESCRIPTION OF FIGURES
[0020]
TABLE-US-00001 Band (cm.sup.−1) Morphology Attribution 3400-3200 weak, enlarged O—H 2930 weak, enlarged C—H 1640-1690 weak C═O 1010 intense, enlarged C—O
[0021]
Spectrum Description:
[0022]
TABLE-US-00002 Band (cm.sup.−1) Morphology Attribution 3400-3200 weak, enlarged O—H 2960 weak, enlarged C—H 1640-1690 medium, enlarged C═O 1010 intense, enlarged C—O
[0023] The differences between these IR spectra (of DE21 and DE21 oxidized) can be easily observed from the intensity of the carbonyl band in 1640-1690 cm.sup.−1. So IR spectroscopy is a useful tool to distinguish the oxidized glucose syrups from non-oxidized.
[0024]
Spectrum Description:
[0025]
TABLE-US-00003 Band (cm.sup.−1) Morphology Attribution 3400-3200 weak, enlarged O—H 2960 weak, enlarged C—H 1640-1690 medium, enlarged C═O 1010 intense, enlarged C—O
[0026]
[0027]
[0028]
.SUP.13.C Magnetic Resonance Spectroscopy Conclusions:
[0029] The .sup.13C NMR spectra (
[0030] The .sup.13C NMR spectra supply spectroscopic evidence that all the examined sugars are oxidized and there is also a distinguish difference between the oxidation process and oxidation products of the present invention in contrast to the prior art oxidation processes and products.
DETAILED DESCRIPTION OF THE INVENTION
[0031] The present invention refers to a process for the preparation of complexes of iron (III) hydroxide and activated glucose syrup comprising, preferably consisting of, the steps:
(i) providing an aqueous solution of glucose syrup, having a dextrose equivalent (DE) of at least 21, as determined by gravimetrical analysis at a temperature in the range of from 25° C. to 80° C. and at a pH in the range of from 6 to 13;
(ii) adding one or more oxidizing bleaching agents, and optionally a catalytic amount of an oxidation catalyst, to the solution of (i), while maintaining the pH and temperature within the range as defined in step (i), allowing the solution to cool down to a temperature in the range of from 10° C. to 45° C., keeping the solution at this temperature for 5 min to 24 hours, thereby obtaining the activated glucose syrup;
(iii) converting said activated glucose syrup into a complex with iron (III) hydroxide; and
(iv) obtaining a complex of iron (III) hydroxide and activated glucose syrup, wherein the oxidizing bleaching agent(s) is/are used in an total amount of 0.0005-0.01 mol/g (glucose syrup) multiplied with the correction factor: (dextrose equivalent of the glucose syrup)/21, wherein the complex has an iron content in the range of from 27 to 35 wt. %, based on the weight of the complex; and wherein the obtained complex of iron (III) hydroxide and activated glucose syrup has more than two —COOH groups per glucose molecule which indicates that the glucose syrup is activated and wherein the glucose syrup of step (i) does not have any —COOH group per/at the glucose molecule.
[0032] The water that is used in step (i) is preferably purified water, which meets the requirements of the current version of the EU Pharmacopoeia at the filing date of the present application. Upon dissolving the glucose syrups, preferably under stirring, a clear solution is obtained. The pH in step (i) is in the range of from 6 to 13, such as 8.5 to 11.5, preferably is in the range of from 10.5 to 11.0. Adjustment of pH in step (i) can be performed by addition of inorganic bases such as aqueous sodium hydroxide (e.g. 40% w/w). The temperature of the solution in (i) is set to a value in the range of from 25° C. to 80° C., preferably between 45° C. and 60° C., more preferably between 48° C. and 55° C. A higher iron content can be obtained when performing step (ii) at a higher pH (see Example 1 and 2). Thus, a pH range of from 10.5 to 13 or from 10.5 to 11.5 is preferred.
[0033] The optional oxidation catalyst, such as NaBr, or mixture of oxidation catalysts is used in catalytic amounts such as 50 nanomols (nM) per g of glucose syrup.
[0034] In step (ii), the oxidizing bleaching agent is preferably slowly added to the solution of step (i), e.g. stepwise, over a period of time, for example 1 to 4 hours. By way of example, Example 1 as described herein, adds 31 g of a 35% (w/w) aqueous solution of hydrogen peroxide at about 0.25 ml/min.
[0035] In step (ii), the glucose syrup is “activated” which means that it is fully oxidized. This means that the present invention oxidizes to a higher extent than the prior art processes. During the addition of the oxidizing bleaching agent, the temperature is kept in the range of from 25° C. to 80° C., preferably between 45° C. and 60° C., more preferably between 48° C. and 55° C.
[0036] After the complete amount of oxidizing bleaching agent has been added, the reaction mixture is allowed to react for some time at the same conditions, e.g. for 5 to 15 minutes, and then allowed to cool down to a temperature of 10-45° C. and is kept at this temperature for a period of time such as 5 min to 24 hours, e.g. 5 hours, while keeping the pH in the range of from 6 to 13, such as 8.5 to 11.5, preferably in the range of from 10.5 to 11.5, such as 10.65 to 10.85.
[0037] Step (iii) of obtaining an activated glucose syrup can include to keep the solution at a temperature in the range of from 18° C. to 25° C. for period of time of from 1 to 10 hours after cooling down the solution after complete addition of the oxidizing bleaching agent and before use of said activated glucose syrup for preparing the desired complex such as by performing steps (iii)(a)-(iii)(c) below.
[0038] The dextrose equivalent (DE) of the activated glucose syrup is preferably in the range of from 0.1 to 1.0, preferably is about 0.3 and/or the obtained complex of iron (III) hydroxide and activated glucose syrup has more than two, preferably more than three —COOH groups per glucose molecule, which indicates that the glucose syrup is activated.
[0039] The molecular weight of the complex is preferably in the range of from 50 kDa to 250 kDa, or 100 to 150 kDa, as measured by high performance liquid chromatography-gel permeation chromatography (HPLC-GPC).
[0040] The step of converting said activated glucose syrup into a complex with iron (III) hydroxide preferably comprises the steps of:
(iii)(a) adding a solution of FeCl.sub.3 to the solution of (ii) at a temperature within the range of from 10 to 30° C.; preferably, the amount of FeCl.sub.3 is in the range of from 30% wt.-% to 120% wt.-% of the amount of glucose syrup.
(iii)(b) adding an inorganic base to the reaction mixture of step (iii)(a) until the pH is within a range of from 1.5 to 2.5; and
(iii)(c) heating the reaction mixture of step (iii)(b) to a temperature within the range of from 40 to 60° C.
[0041] To the solution obtained in step (ii), an aqueous solution of FeCl.sub.3 is added in step (iii)(a). The pH of the solution is then adjusted in step (iii)(b) by using inorganic bases such as Na.sub.2CO.sub.3. In step (iii)(c), the reaction mixture is heated for some time, such as 30 minutes to 1 hour, then preferably, the pH is slowly adjusted to 9-12, further preferred 10-11 by using inorganic bases, such as aqueous NaOH. After some time of reaction at a high temperature, preferably in the range of from 50° C. to 60° C., for example for 1-3 hours, the reaction mixture is cooled to a temperature in the range of from 18 to 25° C. and the pH is then adjusted to be in a range of from 4 to 7, preferably 5-6. The obtained complex can then be purified from the salts by a) ultrafiltration with a cut-off of 30 kDa b) precipitation with ethanol (2:1 to 1:5/solution:ethanol). The final product can then be isolated, e.g. dried, for example by using a spray drier.
[0042] The oxidizing bleaching agents is preferably one or more selected from the group of hydrogen peroxide, ammonium persulfate, sodium and calcium hypochlorite, potassium permanganate and sodium chlorite, most preferably the oxidizing bleaching agent is hydrogen peroxide.
[0043] In one embodiment, 0.001-0.003 mol/g of glucose syrup are used. In one embodiment, about 0.0019 mol/g of glucose syrup, preferably with hydrogen peroxide as the bleaching agent, are used.
[0044] The oxidation catalyst preferably includes bromine and iodine ions.
[0045] The present invention also refers to a complex of iron (III) hydroxide and glucose syrup obtainable or obtained by the process of the present invention.
[0046] The present invention also refers to a pharmaceutical composition comprising a complex of the invention. Said complex or pharmaceutical composition can be used as medicament. Specifically, said complex or pharmaceutical composition can be used in a method of treating iron deficiency in human and animal. The treatment can comprise parenterally administering said complex or pharmaceutical composition.
[0047] Dextrins are carbohydrates with low molecular weight, which can be produced by hydrolysis of starch or glycogen. Dextrins are mixtures of polymers of D-glucose units linked by α-(1-4) or α-(1-6) glycosidic bonds.
[0048] Dextrins can be produced from starch using enzymes like amylases, as during digestion in the human body and during malting and mashing, or by applying dry heat under acidic conditions (pyrolysis or roasting). During roasting under acid condition the starch hydrolyses and short chained starch parts partially rebranch with α-(1,6) bonds to the degraded starch molecule.
[0049] Dextrins are white, yellow, or brown powders that are partially or fully water-soluble, yielding optically active solutions of low viscosity. Most can be detected with iodine solution, giving a red coloration; one distinguishes erythrodextrin (dextrin that colours red) and achrodextrin (giving no colour).
[0050] Maltodextrin consists of D-glucose units connected in chains of variable length. The glucose units are primarily linked with α(1.fwdarw.4) glycosidic bonds. Maltodextrin is typically composed of a mixture of chains that vary from three to seventeen glucose units long.
[0051] Maltodextrins are classified by DE (dextrose equivalent) and have a DE between 3 an 20. The higher the DE value, the shorter the glucose chains, the higher the sweetness, the higher the solubility and the lower heat resistance.
[0052] Above DE 20, the European Union's CN code calls it glucose syrup, at DE 10 or lower the customs CN code nomenclature classifies maltodextrins as dextrins.
[0053] Maltodextrin (see formula below) and glucose syrup are polysaccharide that are used as a food additive. They are produced from starch by partial hydrolysis and are usually found as a white hygroscopic spray-dried powders.
##STR00001##
[0054] Dextrose equivalent (DE) is a measure of the amount of reducing sugars present in a sugar product, relative to dextrose (a.k.a glucose), expressed as a percentage on a dry basis. For example, a maltodextrin with a DE of 10 would have 10% of the reducing power of dextrose (which has a DE of 100). Maltose, a disaccharide made of two glucose (dextrose) molecules has a DE of 52, correcting for the water loss in molecular weight when the two molecules are combined (180/342). For solutions made from starch, it is an estimate of the percentage reducing sugars present in the total starch product.
[0055] Dextrose equivalent (DE) can be measured gravimetrically as described in US 2013/0203698 A1: Dextrins are reacted in a boiling aqueous solution with Fehling's solution. The reaction is carried out quantitatively, i.e. until the Fehling's solution is no longer discoloured. The precipitated copper (I) oxide is dried at 105° C. until a constant weight is achieved and measured gravimetrically. The glucose content (dextrose equivalent) is calculated from the obtained results as % weight/weight of the dextrin dry substance. It is, for example, possible to use the following solutions: 25 ml Fehling's solution I, mixed with 25 ml Fehling's solution II; 10 ml aqueous maltodextrin solution (10% m/vol) (Fehling's solution I: 34.6 g copper (II) sulfate dissolved in 500 ml water; Fehling's solution II: 173 g potassium sodium tartrate and 50 g sodium hydroxide dissolved in 500 ml water) (in addition to the aforementioned method for determining DE values, see also “THE UNIFICATION OF REDUCING SUGAR METHOD”, L. S. Munson and P. H. Walker, J. Am. Chem. Soc. 28 (6), 663-686 (1906)).
[0056] In all glucose polymers, from the native starch to glucose syrup, the molecular chain begins with a reducing sugar, containing a free aldehyde. As the starch is hydrolysed, the molecules become shorter and more reducing sugars are present.
[0057] Thus, the DE value describes the degree of conversion of starch to dextrose, wherein the following definitions are used in the contest of the present invention: starch is close to 0, glucose/dextrose is 100 (percent), dextrins vary between 1 and 13, maltodextrins varies between 3 and 20, glucose syrups contain a minimum of 20% reducing sugars, i.e. a DE of 20. The glucose syrups used in the present invention of a DE of at least 21 and a maximum DE of 60.
[0058] The DE gives an indication of the average degree of polymerisation (DP) for untreated, i.e. not oxidized, starch sugars. The rule of thumb is DE×DP=120.
[0059] The present invention relates to products comprising iron (III) hydroxide and activated glucose syrups. The activation of the glucose syrups is performed by using oxidizing bleaching agents such as hydrogen peroxide, ammonium persulfate, potassium permanganate etc. The main purpose of the bleaching of glucose syrup is to improve the quality of the carbohydrates and facilitate the production and stability of the complex with iron (III) salts in a later step. Surprisingly, in comparison with the previous art which describes methods for the production of complexes of iron (III) hydroxide with oxidation products of dextrins with hypochlorite, we have found that we can produce, according to the present application, stable complexes by extending oxidation, which surprisingly gives high oxidized glucose syrups and stable iron complexes in contrast with the results of the prior art.
[0060] It is well known in the art that the chemistry of hypochlorite oxidation of starches is relatively complex and primarily involves carbons 2, 3 and 6 on a D-glucopyranosyl unit. It is generally agreed that about 25% of the oxidizing reagent is consumed in carbon-carbon splitting while about 75% oxidizes hydroxyl groups.
[0061] In the context of the present invention, it has been found that the activation through the bleaching treatment of glucose syrups gives stable complexes with iron (III) hydroxide.
[0062] The 5% w/w aquatic solutions of these complexes show beyond all expectations, stability over a wide range of pH and there is no precipitation at a pH in the range of from 0 to 14 at 25° C.
EXAMPLES
Example 1
[0063] In a glass reactor are added with continuous stirring 168.0 g of dextrin with DE21 in 268.8 g of purified water. The clear solution is heated to 50° C. and added 840 mg of sodium bromide. The pH of the solution is adjusted to 10.8±0.1 with the addition of a sodium hydroxide solution 40% w/w. In this solution added slowly 31 g of a solution of hydrogen peroxide 35% w/w (0.25±0.02 ml/min) and the pH of the solution remains between 10.65-10.90 with the addition of an aquatic solution of sodium hydroxide 40% w/w. During the addition of hydrogen peroxide the temperature remains between 50 and 55° C. After the end of glucose syrup activation the solution is cooled at room temperature and remains for 5 hours in this temperature with regulation of the pH in the range of 10.65-10.85.
[0064] In this solution is added 296.35 g of a FeCl.sub.3 solution 36.8% w/w with agitation. In this solution is added slowly anhydrous Na.sub.2CO.sub.3 in powder (0.35 to 0.4 g/min) until the pH of the solution reaches the value of 2.4±0.2. The solution is heated to 50° C. and remains at this pH with continuous stirring for 30 min. After the end of this period the pH of the solution is adjusted slowly to 10.5±0.2 with an aquatic solution of sodium hydroxide 40% w/w.
[0065] The complex of iron (III) hydroxide with the activated glucose syrup is stabilized with the heating of the solution at 67±2° C. for 2 hours and then cooled to room temperature. The pH of the solution is brought to 5.5±0.2 and after that the complex is purified from the salts through an ultrafiltration system equipment with a membrane with a cut-off of 30 KDa. The final product is isolated in dry state with the use of a spray drier.
[0066] The physical-chemical analysis of the complex is the following:
[0067] Average molecular weight: 100 KDa.
[0068] Iron (III) content: 31.4%.
Example 2
[0069] In a glass reactor are added with continuous stirring 168.0 g of dextrin with DE21 in 268.8 g of purified water. The clear solution is heated to 50° C. and added 840 mg of sodium bromide. The pH of the solution is adjusted to 8.5±0.1 with the addition of a sodium hydroxide solution 40% w/w. In this solution are added slowly 31 g of a solution of hydrogen peroxide 35% w/w (0.25±0.02 ml/min) and the pH of the solution remains between 8.40-8.60 with the addition of an aquatic solution of sodium hydroxide 40% w/w. During the addition of hydrogen peroxide the temperature remains between 50 and 55° C. After addition of hydrogen peroxide has ended, the solution is cooled to room temperature and remains for 20 hours at this temperature with regulation of the pH in the range of 8.40-8.60.
[0070] To this solution is added 296.35 g of a FeCl.sub.3 solution 36.8% w/w with agitation. In this solution, at room temperature, is added slowly anhydrous Na.sub.2CO.sub.3 in powder (0.35 to 0.4 g/min) until the pH of the solution reaches the value of 2.4±0.2. The solution is heated to 50° C. and remains at this pH with continuous stirring for 30 min. After the end of this period, the pH of the solution is adjusted slowly to 10.5±0.2 with an aquatic solution of sodium hydroxide 40% w/w.
[0071] The complex of iron (III) hydroxide with the activated glucose syrup is stabilized with the heating of the solution at 67±2° C. for 2 hours and then cooled to room temperature. The pH of the solution is brought to 5.5±0.2 and, after that, the complex is purified from the salts through an ultrafiltration system equipment with a membrane with a cut-off of 30 KDa. The final product is isolated in dry state with the use of a spray drier.
[0072] The physical-chemical analysis of the complex is the following:
[0073] Average molecular weight: 150 KDa.
[0074] Iron (III) content: 29.2%.
Example 3
[0075] In a glass reactor are added with continuous stirring 168.0 g of dextrin with DE21 in 268.8 g of purified water. The clear solution is heated to 50° C. and added 840 mg of sodium bromide. The pH of the solution is adjusted to 9.5±0.1 with the addition of a sodium hydroxide solution 40% w/w. In this solution added slowly 31 g of a solution of hydrogen peroxide 35% w/w (0.25±0.02 ml/min) and the pH of the solution remains between 9.40-9.60 with the addition of an aquatic solution of sodium hydroxide 40% w/w. During the addition of hydrogen peroxide the temperature remains between 50 and 55° C. After the end of glucose syrup activation the solution is cooled at room temperature and remains for 5 hours in this temperature with regulation of the pH in the range of 9.40-9.60.
[0076] In this solution is added 296.35 g of a FeCl.sub.3 solution 36.8% w/w with agitation. In this solution is added slowly anhydrous Na.sub.2CO.sub.3 in powder (0.35 to 0.4 g/min) until the pH of the solution reaches the value of 2.4±0.2. The solution is heated to 50° C. and remains at this pH with continuous stirring for 30 min. After the end of this period the pH of the solution is adjusted slowly to 10.5±0.2 with an aquatic solution of sodium hydroxide 40% w/w.
[0077] The complex of iron (III) hydroxide with the activated glucose syrup is stabilized with the heating of the solution at 67±2° C. for 2 hours and then cooled to room temperature. The pH of the solution is brought to 5.5±0.2 and after that the complex is purified from the salts through an ultrafiltration system equipment with a membrane with a cut-off of 30 KDa. The final product is isolated in dry state with the use of a spray drier.
[0078] The physical-chemical analysis of the complex is the following:
[0079] Average molecular weight: 145 KDa.
[0080] Iron (III) content: 30.6%.
Example 4
[0081] In a glass reactor are added with continuous stirring 168.0 g of dextrin with DE25 in 268.8 g of purified water. The clear solution is heated to 50° C. and added 840 mg of sodium bromide. The pH of the solution is adjusted to 8.5±0.1 with the addition of a sodium hydroxide solution 40% w/w. In this solution are added slowly 31 g of a solution of hydrogen peroxide 35% w/w (0.25±0.02 ml/min) and the pH of the solution remains between 8.40-8.60 with the addition of an aquatic solution of sodium hydroxide 40% w/w. During the addition of hydrogen peroxide the temperature remains between 50 and 55° C. After addition of hydrogen peroxide has ended, the solution is cooled to room temperature and remains for 20 hours at this temperature with regulation of the pH in the range of 8.40-8.60 in order to have the complete activation of glucose syrup.
[0082] To this solution is added 296.35 g of a FeCl.sub.3 solution 36.8% w/w with agitation. In this solution, at room temperature, is added slowly anhydrous Na.sub.2CO.sub.3 in powder (0.35 to 0.4 g/min) until the pH of the solution reaches the value of 2.4±0.2. The solution is heated to 50° C. and remains at this pH with continuous stirring for 30 min. After the end of this period, the pH of the solution is adjusted slowly to 10.5±0.2 with an aquatic solution of sodium hydroxide 40% w/w.
[0083] The complex of iron (III) hydroxide with the activated glucose syrup is stabilized with the heating of the solution at 67±2° C. for 2 hours and then cooled to room temperature. The pH of the solution is brought to 5.5±0.2 and, after that; the solution is divided in two equal aliquots and the complex in purified from the salts with the following methods: [0084] a) through an ultrafiltration system equipment with a membrane with a cut-off of 30 KDa. The final product is isolated in dry state with the use of a spray drier. [0085] b) Precipitation of the complex with Ethanol in a range of 1:1. The precipitated complex is dried in a vacuum drier at 48° C.
[0086] The physical-chemical analysis of the complex is the following and is independent from the purification method:
[0087] Average molecular weight: 110 KDa.
[0088] Iron (III) content: 29.8%.
Example 5
[0089] In a glass reactor are added with continuous stirring 168.0 g of dextrin with DE21 in 268.8 g of purified water. The clear solution is heated to 50° C. and added 840 mg of sodium bromide. The pH of the solution is adjusted to 9.5±0.1 with the addition of a sodium hydroxide solution 40% w/w. In this solution are added slowly 31 g of a solution of hydrogen peroxide 35% w/w (0.25±0.02 ml/min) and the pH of the solution remains between 9.40-9.60 with the addition of an aquatic solution of sodium hydroxide 40% w/w. During the addition of hydrogen peroxide the temperature remains between 50 and 55° C. After addition of hydrogen peroxide has ended, the solution is cooled to room temperature and remains for 20 hours at this temperature with regulation of the pH in the range of 9.40-9.60 in order to have the complete activation of glucose syrup.
[0090] To this solution is added 296.35 g of a FeCl.sub.3 solution 36.8% w/w with agitation. In this solution, at room temperature, is added slowly anhydrous Na.sub.2CO.sub.3 in powder (0.35 to 0.4 g/min) until the pH of the solution reaches the value of 2.4±0.2. The solution is heated to 50° C. and remains at this pH with continuous stirring for 30 min. After the end of this period, the pH of the solution is adjusted slowly to 10.5±0.2 with an aquatic solution of sodium hydroxide 40% w/w.
[0091] The complex of iron (III) hydroxide with the activated glucose syrup is stabilized with the heating of the solution at 67±2° C. for 2 hours and then cooled to room temperature. The pH of the solution is brought to 5.5±0.2 and, after that; the solution is divided in two equal aliquots and the complex in purified from the salts with the following methods: [0092] a) through an ultrafiltration system equipment with a membrane with a cut-off of 30 KDa. The final product is isolated in dry state with the use of a spray drier. [0093] b) Precipitation of the complex with Ethanol in a range of 1:1. The precipitated complex is dried in a vacuum drier at 48° C.
[0094] The physical-chemical analysis of the complex is the following and is independent from the purification method:
[0095] Average molecular weight: 112 KDa.
[0096] Iron (III) content: 30.9%.
Molecular Weight Determination of Iron (III) Complexes
[0097] In the context of the present invention, the molecular weight of commercial iron carbohydrate complexes was determined by high performance liquid chromatography-gel permeation chromatography (HPLC-GPC), see United States Pharmacopeia (USP) gel-permeation chromatography method, 28 ed., page 1065.
[0098] The Ferinject® product (of Vifor Pharma) has a molecular weight of 200 kDa. The Ferrum Hausmann® product of Vifor Pharma (oral solution) is an iron polymaltose complex having a molecular weight of 50 kDa. The Ferrum Hausmann® product of Vifor Pharma (injectable solution) has a molecular weight of 350 kDa. Furthermore, Example 3 of US2013/0203698 A1 was repeated twice and the molecular weight was determined to be 400 kDa and 450 kDa respectively.
TABLE-US-00004 TABLE 1 Molecular weight and iron content of iron (III) complexes. Molecular Weight (MW) Iron content Example 1 100 KDa Assay.sub.Fe(III): 31.4% w/w Example 2 150 KDa Assay.sub.Fe(III): 29.2% w/w Example 3 145 KDa Assay.sub.Fe(III): 30.6% w/w Example 4 110 KDa Assay.sub.Fe(III): 29.8% w/w Example 5 112 KDa Assay.sub.Fe(III): 30.9% w/w US2013/0203698 A1 140 KDa Assay.sub.Fe(III): 26.8% w/w (Example 3) (data given in (data given in the reference) the reference) US2013/0203698 A1 test 1 test 1 (Example 3- 400 KDa Assay.sub.Fe(III): 25.2% w/w reworked) test 2 test 2 450 KDa Assay.sub.Fe(III): 25.4% w/w US2013/0203698 A1 >450 KDa Assay.sub.Fe(III): 24.6% w/w (Example 1- reworked) US2013/0203698 A1 >450 KDa Assay.sub.Fe(III): 12.8% w/w (Example 2- reworked) US2013/0203698 A1 450 KDa Assay.sub.Fe(III): 15.9% w/w (Example 8- reworked)
[0099] A comparison of US2013/0203698 with a complex of the present invention provided the following results:
TABLE-US-00005 TABLE 2 Differences between US2013/0203698 Example 1 and the present invention. Example 2 Example 1 of of the present US2013/0203698 application Oxidative reagent NaClO 15% H.sub.2O.sub.2 35% .sup.13C NMR 2 carbonyl groups (—COOH ) 4 carbonyl groups (—COOH) Sugar DE 9.6 21 Activated sugar DE 1.1 0.3 Complex MW >450 kDa 150 kDa Fe (III) content 24.6% 29.2%
CITED LITERATURE
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