FORM 2
THE PATENTS ACT, 1970 (39 Of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. TITLE OF THE INVENTION :
"PROCESS FOR THE PREPARATION OF IRON COMPOUNDS"
2. APPLICANT (S)
(a) NAME : EMCURE PHARMACEUTICALS LTD.
(b) NATIONALITY : India
(c) ADDRESS : R&D Centre, T-184, MIDC, Bhosari,
Pune 411 026, Maharashtra, India,

FIELD OF INVENTION:
The present invention relates to process for the preparation of sodium ferric gluconate complex in sucrose.
BACKGROUND OF THE INVENTION:
Sodium ferric gluconate complex in sucrose has been known for about 40 years. It has been utilized primarily as an injectable agent for treating iron deficiencies in animals and human patients, having several advantages over other iron preparations. The advantageous are low toxicity, low incidence of adverse reactions and satisfactory rate of iron absorption.
Sodium ferric gluconate complex in sucrose injection (SFGC) is an iron formulation marketed in the United States as Ferrlecit (Watson Pharma, Inc., Morristown, NJ). The U.S. Food and Drug Administration (FDA) approved this formulation in 1999 for treatment of iron-deficiency anemia in patients undergoing chronic hemodialysis who receive supplemental erythropoietin therapy (www.medscape.com/viewarticle/478589).
Patients who undergo hemodialysis have chronic iron losses and a deficiency of erythropoietin. When exogenous erythropoietin is administered, oral iron supplements cannot always supply iron at a rate sufficient to support optimal erythro-poiesis, and intravenous iron is needed. Before SFGC gained FDA approval, two commercial forms of iron dextran were the only intravenous iron products approved for use in the United States.
The SFGC formulation is effective in treating iron deficiency, and it has a better safety profile, which is associated with rare but potentially serious anaphylactic reactions. The SFGC is a stable macromolecular complex with an apparent molecular weight of 350,000 ± 23,000 Daltons (www.fda.gov/cder/foi/label/1999/20955lbl.pdf).
The US 6,693,211 is issued to Geneva Pharmaceuticals Inc., on February 17, 2004 discloses a process for the preparation of sodium ferric gluconate complex and sodium
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ferric gluconate complex in sucrose, wherein ferric (III) chloride hexahydrate is dissolved in water and to it added weak base like sodium carbonate solution to neutralize the pH. The precipitated ferric oxyhydroxide is filtered and washed several times with water to remove the chloride salts.
The above isolated ferric oxyhydroxide is suspended in water. To it sodium gluconate solution in water is added and heated the reaction mass to 70-80° C, and further maintained the reaction mass at 70-80° C for 2 hours. The water is removed under reduced pressure, followed by addition of methanol at room temperature. The precipitated solid is filtered and washed with methanol, which is subjected to freeze drying to get sodium ferric gluconate complex. The sodium ferric gluconate complex is dissolved in aqueous sucrose solution to get sodium ferric gluconate complex in sucrose.
The drawbacks of the above process are as follows:
i) filtration of ferric (III) oxyhydroxide is slow, which needs more time and
hence increases the time cycle, ii) ferric (III) oxyhydroxide prepared according to the process also holds the
impurities, which needs repeated water washings to remove said impurities
and get the desire quality.
US 7,005,531 patent is filed on November 18, 2004; it is a continuation of application No. PCT/CH04/000299, filed on May 17, 2005. This patent has been issued to Cilag AG on February 28, 2006. This patent teaches the process for the preparation of sodium ferric gluconate / sodium ferric gluconate complex in sucrose, wherein iron (III) chloride hexahydrate is reacted with sodium bicarbonate solution to precipitate iron (III) oxyhydroxide, the said iron (III) oxyhydroxide is reacted in-situ with gluconic acid or sodium gluconate in the presence of sodium hydroxide. The reaction mixture is heated to reflux temperature. After formation of the complex, water is removed under reduced pressure followed by addition of acetone or methanol to precipitate the solid, which is filtered, washed, dried to get sodium ferric gluconate complex.

The major drawbacks of the above process are listed below:
i) iron (III) oxyhydroxide is not isolated as a solid and it higher salts and
chloride content, which is carried over to the next reaction of treatment with
gluconic acid / gluconic acid derivatives in the presence of base. Thus, the
reaction mass accumulates more inorganic salts, ii) sodium ferric gluconate complex filtration is slow, which may hold salts to
increase the impurities, iii) sodium ferric gluconate complex needs repeated washings /crystallizations to
remove impurities and get the desired quality
Both the above processes require utilities and are time consuming, laborious and demanding more manpower requirement. These aspects lead to increase the cost of the final product.
US 20040161852, US 6,929,954, US 6,537,820, US 6,773,924, US 20050272163, US6,939,715, US 6,911,342 these patents though related to sodium ferric gluconate complex in sucrose, does not teach the preparation of commercial scale.
The above processes need to improve the filtration of ferric (III) oxyhydroxide and sodium ferric gluconate complex. We have found out the fast filtration of ferric (III) oxyhydroxide and sodium ferric gluconate complex, wherein iron (III) chloride is reacted with water miscible amine to get ferric (III) oxyhydroxide and filtration is fast as comparatively prior art processes.
OBJECT OF THE INVENTION:
An object of the present invention is to improve the filtration of ferric (III) oxyhydroxide and sodium ferric gluconate complex in sucrose.
A still further object of the invention is to provide the commercially feasible process for the preparation of the sodium ferric gluconate complex in sucrose.
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Yet another object of the present invention is to avoid the purification steps of sodium ferric gluconate.
SUMMARY OF THE INVENTION:
The present invention provides the process with reasonably fast filtration of ferric oxyhydroxide and sodium ferric gluconate complex.
The present invention further provides an improved and industrially feasible process for the preparation of sodium ferric gluconate complex in sucrose.
DETAILED DESCRIPTION OF THE INVENTION:
The invention relates to the process for the preparation of sodium ferric gluconate complex in sucrose, wherein iron (III) salt is reacted with water soluble amine in water followed by filtration to get ferric (III) oxyhydroxide. The isolated ferric (III) oxyhydroxide is suspended in water then reacted with gluconic acid / gluconate acid derivative with or without base. After completion of the reaction, the reaction mass is added into water miscible/immiscible solvent to get the sodium ferric gluconate. In other . way reaction mass is diluted with water miscible/ immiscible solvent to get the sodium ferric gluconate complex. Optionally sodium ferric gluconate complex is prepared without isolation of ferric oxyhydroxide. It is in-situ reacted with gluconic acid / gluconic acid derivative with or without base to get sodium ferric gluconate complex (SFGC).
The present invention provides the commercially feasible process for the preparation of sodium ferric gluconate with improved yield and reduced time cycle, which comprises the steps of:
a. reacting iron (III) salt with a base in water to obtain ferric (III) oxyhydroxide;
b. reacting ferric (III) oxyhydroxide with a gluconic acid / gluconic acid derivative
with or without a base to form sodium ferric gluconate complex;
c. contacting reaction mass with a water miscible or water immiscible organic
solvent to obtain a solid precipitate which is isolated; and
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d. combining sodium ferric gluconate complex in aqueous sucrose to obtain desired sodium ferric gluconate complex in sucrose.
The iron (III) salts are selected from the group comprising of ferric (III) chloride, ferric (III) chloride hexahydrate and ferric (III) nitrate. The preferred iron (III) salt is ferric (III) chloride hexahydrate.
The base is selected from organic and inorganic base , the organic base is water-soluble
amine groups selected from group comprising of trishydroxymethylaminoethane,
diethanolamine, ethanolamine, ethylenediamine, tetraethylenediamine,
hexamethylenetetramine, diethylaminoethanol and aminoethylethanolamine. The preferred water soluble amine is hexamethylenetetramine.
The inorganic base is selected form the group comprising of sodium carbonate, sodium bicarbonate, potassium carbonate and potassium bicarbonate.
The reaction pH during formation of ferric oxyhydroxide is maintained between 4.0-6.0 and the preferred reaction mass pH is 5.0-5.5. The reaction mass temperature is maintained between 10-50° C, the preferred reaction temperature is 20-25° C. The separated solid is filtered and washed with water to get ferric (III) oxyhydroxide.
Optionally, the above isolated ferric (III) oxyhydroxide is suspended in water. To it added gluconic acid / gluconic acid derivative and the reaction mass pH is adjusted to 8-13 using the base. The reaction mass is heated to 50-90°C.
After formation of complex, the reaction mass is cooled to room temperature and diluted with water miscible / immiscible organic solvent to precipitate the complex, which is filtered and washed with mixture of water and water miscible / immiscible solvent. The complex dried to get the sodium ferric (III) gluconate complex. The gluconic acid derivatives are selected from the group comprising of alkali earth metal salt of gluconic acid. The preferred gluconic acid derivative is sodium gluconate.
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The reaction mass pH is adjusted to 10-13 and preferred reaction mass pH is 11.0 -12.0. The reaction mass pH is adjusted by using sodium hydroxide. The reaction is heated to 50-90° C, the preferred reaction temperature is 55-65° C. After formation of the complex, the reaction is cooled to room temperature and the reaction mass pH is adjusted to 7.0-7.5 with acid, the acid is selected form the group comprising hydrochloric acid, hydrobromic acid , sulphuric acid, phosphouric acid and formicacid. The resulting solution is treated with carbon and filtered, concentrate the same under reduced pressure to get the slurry. The slurry is added into water miscible / immiscible organic solvents or vise versa for isolation. The water miscible solvent is selected from the group comprising methanol, ethanol, isopropyl alcohol, acetonitrile, tetrahydrofuran, dioxane, dimethylformamide, dimethylacetamide and N-methylpyrrolidinone. The preferred water miscible organic solvents are methanol and acetone and most preferred water miscible organic solvent is methanol. The water immiscible solvent is n-butanol.
The precipitated complex is filtered and washed with a mixture of water and the organic solvents followed by drying to get sodium ferric (III) gluconate complex, The wash can be on the funnel it self or taking the wet cake in the reaction flask and mixing with a mixture of water and water miscible / immiscible solvent to get the pure sodium ferric (III) gluconate complex. The water miscible solvent group is selected from the group comprising methanol, ethanol, isopropyl alcohol, acetonitrile, tetrahydrofuran, dioxane, dimethylformamide, dimethylacetamide and N-methylpyrrolidinone. The preferred water miscible organic solvents are methanol and acetone and more preferred water miscible organic solvent is methanol. The preferred water immiscible organic solvent is n-butanol.
The isolated ferric (III) oxyhydroxide is suspended in water. To it added gluconic acid / gluconic acid derivative and the reaction mass is heated to 60-100° C without addition of base.
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After formation of complex, the reaction mass is cooled to room temperature and diluted with water miscible / immiscible organic solvent to precipitate the complex, which is
filtered and washed with mixture of water and water miscible / immiscible solvent. The
complex is dried to get the sodium ferric (III) gluconate complex.
The gluconic acid derivatives are selected from the group comprising of alkali earth metal salt of gluconic acid. The preferred gluconic acid derivative is sodium gluconate.
The reaction is heated to 60-120° C, the preferred reaction temperature is 80-90° C. After formation of the complex, the reaction is cooled to room temperature and the reaction mass is treated with carbon and filtered, concentrate the same under reduced pressure to get the slurry, which is added into water miscible / immiscible organic solvents. The water miscible solvent is selected from the group comprising methanol, ethanol, isopropyl alcohol, acetonitrile, tetrahydrofuran, dioxane, dimethylformamide, dimethylacetamide and N-methylpyrrolidinone. The preferred water miscible organic solvents are methanol and acetone and most preferred water miscible organic solvent is methanol. The water immiscible solvent is n-butanol.
The precipitated complex is filtered and washed with a mixture of water and the organic solvents followed by drying to get sodium ferric (III) gluconate complex. The wash can be on the funnel it self or taking the wet cake in the reaction flask and mixing with a mixture of water and water miscible / immiscible solvent to get the pure sodium ferric (III) gluconate complex. The water miscible solvent group is selected from the group comprising methanol, ethanol, isopropyl alcohol, acetonitrile, tetrahydrofuran, dioxane, dimethylformamide, dimethylacetamide and N-methylpyrrolidinone. The preferred water miscible organic solvents are methanol and acetone and more preferred water miscible organic solvent is methanol. The preferred water immiscible organic solvent is n-butanol.
The "particle size" of the isolated product and the "nature of the solid" is of acceptable standards in order to prepare the pharmaceutical composition.
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Further, the above isolated sodium ferric (III) gluconate complex is dissolved in sucrose in water to get sodium ferric gluconate complex in sucrose.
The ferric oxyhydroxide prepared as per the above process is used for making iron sucrose as well as the iron dextron.
The ferric oxyhydroxide is suspended in water and added into aqueous sucrose at ambient temperature then the reaction mass is heated to 70-90° C. The reaction mass pH is adjusted with inorganic base between 9.0-12.0., maintained the reaction mass for another 2-3 hours at same temperature. After formation of the complex, the reaction mass is concentrated under reduced pressure to get slurry, which is added into water miscible organic solvents or vice-versa to get the ironsucrose.
In the same way ferric oxyhydroxide is suspended in water and dextran is added at room temperature. The reaction mass pH is adjusted with inorganic base between 10-13.0, resulting reaction mixture is heated to 80-90° C. The reaction mass is maintained for another 4-6 hours. After formation of the complex, the reaction mass is concentrated under reduced pressure to get slurry, which is added into water miscible organic solvents or vice-versa to get the iron dextran.
The major advantages of the present invention are as follows:
i) ferric (III) oxyhydroxide and sodium ferric (III) gluconate complex filtration
is fast, ii) avoided repeated washing to remove the salts, iii) sodium ferric (III) gluconate yield is improved with reduces time cycle.
The principles, preferred embodiments, and modes of operation of the present invention have been described in the foregoing specification. The invention which is intended to be protected herein, however, is not to be construed limited to the particular forms disclosed, since these are to be regarded as illustrative rather than restrictive. Variations and
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changes may be made by those skilled in the art, without departing from the spirit of the invention.
The present invention is more particularly illustrated in the following example(s), but is not to limit the scope of the present invention.
Example-1
Process for the preparation of Sodium (III) ferric gluconate (without slurry wash):
Ferric (III) chloride hexahydrate 200 gm (0.739mole) was dissolved in DM water 4000 ml under stirring. Hexamethylenetetramine solution (414 gm; 1.478 moles in 1250 ml DM water) was added at 20-25° C. The precipitated solid was filtered and washed with water (4 X 200) ml gives ferric (III) oxyhydroxide. The ferric (III) oxyhydroxide was suspended in DM water 550-600 ml under stirring at 25-30° C. Sodium gluconate solution (49 gm; 0.111moles in 243 ml DM water) was added into ferric (III) oxyhydroxide suspension. The reaction mass was heated. 15% sodium hydroxide solution was added. The reaction mass was maintained for 3 hours at 70-80° C. The reaction mass was cooled to room temperature and treated with carbon, filtered. The reaction mass was concentrated and was charged into methanol 2000 ml at room temperature over a period of 2 hours. The precipitated solid was filtered and washed with 15% aq. methanol 2x200 ml gives sodium ferric (III) gluconate complex.
Dry weight: 90 gm
Example-2
Process for the preparation of Sodium (III) ferric gluconate (with slurry wash):
Ferric (III) chloride hexahydrate 100 gm (0.369mole) was dissolved in DM water 2000 ml under stirring. Hexamethylenetetramine solution (206.8 gm; 1.478 moles in 620 ml DM Water) was added at 20-25° C. The precipitated solid was filtered and washed with water (2 X 100) ml gives ferric (III) oxyhydroxide. The ferric (III) oxyhydroxide was suspended in DM water 280 ml under stirring at 25-30° C. Sodium gluconate solution
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(24.30 gm; 0.111 moles in 243 ml DM water) was added into ferric (III) oxyhydroxide suspension. The reaction mass was heated. 15% Sodium hydroxide solution was added. The reaction mass was maintained for 3 hours at 70-80° C. The reaction mass was cooled to room temperature and treated with carbon, filtered. The reaction mass was concentrated and was charged into methanol 1000 ml at room temperature over a period of 2 hours. The precipitated solid was filtered and washed with methanol 2x200 ml gives sodium ferric (III) gluconate complex. Dry weight: 55 gm
The ferric (III) gluconate complex 50 gm was suspended in a mixture of water 50ml and methanol 250ml under stirring at room temperature for 1 hour. The solid was filtered and washed with methanol (50 X 2) ml, dried under vacuum at 50-60°C to give sodium (III) ferric gluconate. Dry weight: 45 gm
Example-3
Process for the preparation of Sodium (III) ferric gluconate (without slurry wash):
Ferric (III) chloride hexahydrate 9 gm (0.033mole) was dissolved in DM water 180 ml under stirring. Hexamethylenetetramine solution (18.63 gm; 0.132 moles in 56 ml DM water) was added at 20-25° C. The precipitated solid was filtered and washed with water (2 X 9) ml gives ferric (III) oxyhydroxide. The ferric (III) oxyhydroxide was suspended in DM water 25 ml under stirring at 25-30° C. Sodium gluconate solution (2.20 gm; 0.010 moles in 11 ml DM water) was added into ferric (III) oxyhydroxide suspension. The reaction mass was heated. 15% sodium hydroxide solution was added. The reaction mass was maintained for 3 hours at 70-80° C. The reaction mass was cooled to room temperature and treated with carbon, filtered. The reaction mass was concentrated and was charged into methanol 90 ml at room temperature over a period of 2 hours. The precipitated solid was filtered and washed with 15% aq. methanol 2x9 ml gives sodium ferric (III) gluconate complex.
Dry weight: 4.05
Yield 1.84 w/w on the basis of sodium gluconate
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Example -4
Ferric (III) chloride hexahydrate 9 gm (0.033mole) was dissolved in DM water 200 ml under stirring. Sodium carbonate (5.4 gm; 0.050 moles in 150 ml DM water) was added at 20-25° C. The precipitated solid was filtered washed with water (5 X 125) ml gives ferric (III) oxyhydroxide. The ferric (III) oxyhydroxide was suspended in DM water 300 ml under stirring at 25-30° C. Sodium gluconate solution 3.7 gm (0.016 moles) was added into ferric (III) oxyhydroxide suspension. The reaction mass was heated. 15% sodium hydroxide solution was added. The reaction mass was maintained for 3 hours at 70-80° C. The reaction mass was cooled to room temperature and treated with carbon, filtered. The reaction mass was concentrated, methanol 334 ml was charged into the residue . The precipitated solid was filtered and washed with methanol gives sodium ferric (III) gluconate complex.
Dry weight: 6.0
Yield 1.62 w/w on the basis of sodium gluconate
Comparative table

Processes Time required for Ferric oxyhydroxide filtration Water required for washing ferric oxyhydroxide Time required for Sodium ferric gluconate Sodium ferric gluconate complex Yield(w/w)1.62 Totaleffluentgenerated
Prior art Process US'211 180 min. 625 ml 135 min. 1.62 975 ml
Ex.4
Instant Process 90 min. 18 ml 30 min. 1.84 257 ml
Ex.3
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It is clear from the above table that the time required for preparation of ferric gluconate Complex as per the process of the present invention is far less as compared to the process used in the prior art. Thus, the use of amine for preparation of ferric gluconate complex provides various advantages including quick filtration, avoiding repeated washing as also improved yield of ferric gluconate.
Example-5
Process for the preparation of Sodium (III) ferric gluconate (without addition of base along with sodium gluconate):
Ferric (III) chloride hexahydrate 25 gm (0.092 mole) was dissolved in DM water 500 ml under stirring. Hexamethylenetetramine solution (65.00gm; 0.462 moles in 200 ml DM water) was added at 20-25° C. The precipitated solid was filtered and washed with water (3 X 25) ml gives ferric (III) oxyhydroxide.
The ferric (III) oxyhydroxide was suspended in DM water 250 ml under stirring at 25-30° C. Sodium gluconate solution (10.03 gm; 0.046 moles in 100 ml DM water) was added into ferric (III) oxyhydroxide suspension. The reaction mass was heated and maintained for 6 hours at 80-90° C. The reaction mass was cooled to room temperature and treated with carbon, filtered. The reaction mass was concentrated and was charged into methanol 250 ml at room temperature over a period of 2 hours. The precipitated solid was filtered and washed with 15% aq. methanol 2x25 ml gives sodium ferric (III) gluconate complex. Dry weight: 14.70 gm
Example-6
Process for the preparation of Sodium (III) ferric gluconate (by using Tris-hydroxymethylamino methane):
Ferric (III) chloride hexahydrate 100 gm (0.369 mole) was dissolved in DM water 2000 ml under stirring. Tris-hydroxymethylamino methane (156.0 gm; 1.287 moles) was added at 20-25° C. The precipitated solid was filtered and washed with water (4 X 100 ml) gives ferric (III) oxyhydroxide.
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The ferric (III) oxyhydroxide was suspended in DM water 350 ml under stirring at 25-30° C. Sodium gluconate (24.30 gm; 0.111 moles) was added into ferric (III) oxyhydroxide suspension. The reaction mass was heated then 15% sodium hydroxide solution was added. The reaction mass was maintained for 3 hours at 70-80° C. The reaction mass was cooled to room temperature and treated with carbon and filtered. The reaction mass was concentrated and was charged into methanol 1000 ml at room temperature over a period of 2 hours. The precipitated solid was filtered and washed with 15% aq. methanol 2x100 ml gives sodium ferric (III) gluconate complex. Dry weight: 55 gm
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WE CLAIM:
1. Process for the preparation of sodium ferric gluconate complex in sucrose , comprising the steps of:
a. reacting iron (III) salt with a base in water to obtain ferric (III) oxyhydroxide;
b. reacting ferric (III) oxyhydroxide with a gluconic acid / gluconic acid derivative
with or without a base to form sodium ferric gluconate complex;
c. contacting reaction mass with a water miscible or water immiscible organic
solvent to obtain a solid precipitate which is isolated; and
d. combining sodium ferric gluconate complex in aqueous sucrose to obtain desired
sodium ferric gluconate complex in sucrose.
2. A process according to claim 1 step(a), wherein iron (III) salt is selected from the
group comprising of ferric (III) chloride, ferric (III) chloride hexahydrate and ferric (III) nitrate.
3. A process according to claim 2, wherein the preferred iron (III) salt is ferric (III) chloride hexahydrate.
4. A process according to claim 1 step (a), wherein the base is a water soluble
amine.
5. A process according to claim 4, wherein the water soluble amine is selected from the group comprising of trishydroxymethylaminoethane, diethanolamine, ethanolamine, ethylenediamine, tetraethylenediamine, hexamethylenetetramine, diethylaminoethanol and aminoethylethanolamine.
6. A process according to claim 5, wherein the preferred water-soluble amine is
hexamethylenetetramine.
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7. A process according to claim 1 step (b), wherein said gluconic acid derivative is
sodium salt of gluconic acid.
8. A process according to claim 1 step (b), wherein said base is sodium hydroxide.
9. A process according to claim 1 step (c), wherein the reaction mass is added into a
water miscible organic solvent..
10. A process according to claim 1 step (c), wherein water miscible organic solvent is added into reaction mass.
11. A process according to claim 9 and 10, wherein water miscible organic solvent is selected from the group comprising methanol, ethanol, isopropyl alcohol, acetonitrile, tetrahydrofuran, dioxane, dimethylformamide, dimethylacetamide and N-methylpyrrolidinone.
12. A process according to claim 9, wherein the preferred water miscible organic solvent is alcohol.
13. A process according to claim 10, wherein the preferred alcohol is methanol.
14. A process as claimed in claim 1 step (b), wherein when step (b) is performed without a base, the reaction mass is heated from 60-120°C, preferably 80-90°C.
15. A process as claimed in claim 1 step (c), wherein, the water immiscible organic solvent is n-butanol.
16. A process as claimed in claim 1 step (c), wherein sodium ferric (III) gluconate is isolated.
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17. A process for preparation of sodium ferric gluconate, substantially as herein described in the foregoing examples.
Dated this 14th day of September, 2006.

[RAJESHWARI H.]
OF K&S PARTNERS
ATTORNEY FOR THE APPLICANT
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ABSTRACT
Title: " Process for the preparation of iron compound"
The present invention provides the process for the preparation of sodium ferric gluconate complex in sucrose. The iron (III) salt is reacted with water-soluble amine in water followed by filtration to get ferric oxyhydroxide. The isolated ferric oxyhydroxide is suspended in water and reacted with gluconic acid / gluconic acid derivatives with or without base. After completion of the reaction, reaction mass is added into water miscible / immiscible solvents or vise versa to get the sodium ferric gluconate complex. Optionally sodium ferric gluconate complex is prepared without isolation of ferric oxyhydroxide, which is in-situ reacted with gluconic acid /gluconic acid derivative-with or witout base to get sodium ferric gluconate complex (SFGC). SFGC is further converted into sodium ferric gluconate complex in sucrose.
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