FIELD OF THE INVENTION

[001] The present invention relates to a pharmaceutically acceptable Ferric Carboxymaltose and preparation thereof. Particularly, the present invention relates an economically feasible, facile and robust route to prepare pharmaceutically acceptable Iron (III) Carbohydrate Complex, particularly, Ferric Carboxymaltose. More particularly, the present invention relates to pharmaceutical composition of Iron (III) Carbohydrate Complex which can be administered as intervenous (IV) dose as to allow better release of iron in the biological system to ensure less hypersensitivity, thus lowering the chances of anaphylactic shock with better patient compliance.

BACKGROUND OF THE INVENTION

[002] Iron being an essential trace element, plays a key role in making of red blood cells, which deliver the oxygen to the tissues in body. The iron deficiency anemia (IDA) is the most common hematological disease with potentially serious clinical consequences faced by a majority of worldwide population. Initially oral iron replacement theory was implemented to combat Iron Deficiency Anemia (IDA), however long term treatment was required to adequately replete iron stores. Further it was associated with gastrointestinal adverse side effect along with low intestinal absorption of iron. In order to overcome this problem, researchers developed first parenteral iron preparations in the form of colloidal ferric hydroxide which were used clinically, however toxicity linked to the release of large amounts of labile iron limited their use. This prompted the development of preparations composed of an iron core and carbohydrate shell that prevented rapid release of the elemental iron, thus came into use Inter Venous (IV) administered iron carbohydrate complex. [003] Their characteristic, strongly-bound iron-carbohydrate complexes exist as colloidal suspensions of iron oxide nanoparticles with a polynuclear Fe (III)- oxyhydroxide/oxide core surrounded by a carbohydrate shell. These iron complexes are stable on the shelf and are modified upon intravenous administration.

[004] US2018/0105609 Al discloses a process for the preparation of ferric carboxymaltose comprising oxidation of maltodextrins using organic hypo-halite in the presence of catalyst such as transition metal catalyst and phase transfer catalyst and subsequently reacting the obtained oxidized maltodextrin with ferric hydroxide to produce ferric carboxymaltose with inconsistence in the molecular weight. The said process also involves usage of expensive reagents and also additional reagents in the process. This results in increase in the production cost and hence making the process uneconomical and not suggested for commercial scale.

[005] IN3463/MUM/2011 discloses a process for the preparation of ferric carboxymaltose comprising oxidation of maltodextrin with sodium hypochlorite to provide oxidized maltodextrin followed by reacting with iron (III) salt to provide ferric carboxymaltose. The said process involves addition of sodium hypochlorite at higher temperatures i.e.at 65-70°C which is not suggested. As sodium hypochlorite explodes on heating and hence the said process is not recommended for commercial scale.

[006] US20120214986A1 discloses process for the preparation of ferric carboxymaltose comprising oxidation of maltodextrins using an aqueous sodium hypochlorite solution and subsequently reacting the obtained oxidized maltodextrin with ferric hydroxide to produce ferric carboxymaltose with inconsistent molecular weight.

[007] Therefore, the process disclosed in the art is found to be unsuitable for providing economically feasible ferric carboxymaltose having consistent molecular weight. [008] Thus, there is a need for development of a feasible, facile and robust route for the synthesis of pharmaceutically acceptable ferric carboxymaltose which is preferably free of impurities, stable in nature and that can minimize range of the average molecular weight.

OBJECTIVE OF THE INVENTION

[009] The main objective of present invention is to provide a pharmaceutically acceptableferric carboxymaltose with increased stability and shelf life.

[0010] Another objective of the present invention is to provide Ferric carboxymaltose complex particularly Iron (III) carbohydrate complex having high purity, low endotoxin limit, with minimal labile iron content.

[0011] Yet another objective of the present invention is to provide Ferric carboxymaltose having average molecular weight in a minimized range so as to produce less toxic product which ensures control release of elemental iron into the biological system.

[0012] Yet another objective of the present invention is to provide hypersensitivity free ferric carboxymaltose.

[0013] Yet another objective of the present invention is to provide an economically feasible, facile and robust route to prepare pharmaceutically acceptableferric carboxymaltose without using any reagent.

[0014] Yet another objective of the present invention is tosynthesize ferric carboxymaltose from a novel oxidation route.

[0015] Yet another objective of the present invention is to provide a pharmaceutical composition of ferric carboxymaltose in which the ratio of divalent iron to trivalent iron is less than 1 % which ensures no oxidative stress induced in body. SUMMARY OF THE INVENTION

[0016] The present invention relates to a pharmaceutical acceptable Ferric Carboxymaltose having improved characteristics prepared through a robust, economical and simple synthetic route. The process comprises of electrolytic oxidation of carbohydrate followed by isolation of the oxidized carbohydrate. Further, the oxidized carbohydrate is reacted with freshly prepared ferric hydroxide cake under stirring condition at pH 6-7 and heating at 85-90°C for about a period of 4to 6 hours till clear reddish brown solution is obtained. The solution is sequence filtered and spray dried and the product so obtained has a total iron content in the range of 30-34% w/w and the average molecular weight in the range of 80 kDa-250kDa.The ratio of divalent to trivalent iron is found to be not more than 1 % wherein ferrous content is determined titrimetrically using potassium dichromate standard solution ensuring the ferrous content to be less than l%.The ferric carboxymaltose has reduced content of dimer carbohydrate moiety to less than about 2% which indicates reduced toxicity profile.

[0017] The present invention also provides a pharmaceutical composition comprising ferric carboxymaltose which is improved with less or no side effects, low labile content and reduced toxicity.

BRIEF DESCRIPTION OF FIGURES

[0018] Figure 1 illustrates Transmission Electron Microscope data of Ferric Carboxymaltose;

[0019] Figure 2 illustrates Scanning Electron Microscope of Ferric Carboxymaltose;

[0020] Figure 3 illustrate X-ray diffraction of Ferric Carboxymaltose; and

[0021] Figure4 illustrates Thermogravimetric Analysis (TGA) of Ferric Carboxymaltose.

DETAILED DESCRIPTION OF THE INVENTION [0022] The following embodiments set forth herein below are merely exemplary out of the wide variety and arrangement of instructions which can be employed in the present invention within the scope of the present claims. The present invention may be exemplified in other specific forms without departing from the spirit or essential characteristics thereof.

[0023] Accordingly, various changes and modification of the embodiments described herein can be made without departing form the scope of the invention.

[0024] Thus, accordingly those ordinarily skilled in art can recognise such alternatives, which shall not affect the novelty of the process.

[0025] Thus, unless expressly stated otherwise, they all are within the scope of the present invention.

[0026] In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.

[0027] The terms and words used in the following description and claims are not limited to the bibliographical meanings but are merely used to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention.

[0028] It is to be understood that the singular forms “a”, “an” and “the” include plural referents unless the context clearly dictates otherwise.

[0029] It should be emphasized that the term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. [0030] Accordingly, the present invention relates to a pharmaceutically acceptable Iron (III) carbohydrate complex, particularly, ferric carboxymaltose with better characterisation for bio-available iron. The pharmaceutically acceptable Iron (III) carbohydrate complex has reduced impurity profile which helps in a better intervenous administration of product in a single dose in the biological system.

[0031] In a preferred embodiment, the present invention relates to a pharmaceutically acceptable Iron (III) carbohydrate complex, particularly ferric carboxymaltose complex and a process of preparation thereof. The present invention provides a process having the controlled oxidation step to minimize range of the average molecular weight of ferric carboxymaltose with reduced toxicity profile and improved characteristics, and which can be administered as intervenous (IV) dose so as to allow better release of iron in the biological system to ensure less hypersensitivity, thus lowering the chances of anaphylactic shock with better patient compliance.

[0032] In an embodiment, the present invention provides a process for synthesizing a pure pharmaceutically acceptable ferric carboxymaltose. The complex is prepared through organic free solvent route. The processcomprises of three major steps: a. Preparation of oxidized carbohydrate; b. Preparation of ferric hydroxide; and c. Preparation of ferric carboxymaltose.

[0033] Step (A): Preparation of oxidized carbohydrate i. adding water to carbohydratein a ratio ranging between 2:1 to 4: lin a reactor at a temperature ranges from 25-30°C followed by stirring for a period ofl to 1.5 hour at the same temperature to obtain a clear aqueous solution of carbohydrate; ii. oxidizing the obtained aqueous solution of carbohydrate electrolytically in the presence of catalytic amount of a temperature 25 to 35 °C for different time periods to obtain the completely oxidized carbohydrate; and iii. isolating the oxidized carbohydrate in the presence of organic solvent to obtain substantially low molecular weight carbohydrate complex.

[0034] The carbohydrate undergoes electrolytic oxidation in an electrolyzer in the presence of salt in an amount of 0.5- 1.5 equivalent, preferably in the range of 0.8- 1.2 equivalent of one aldehyde group per molecule of the carbohydrate to be oxidized. This ensures that the oxidation takes place at the terminal aldehyde group of the carbohydrate.

[0035] The oxidation is completed in the presence of catalytic amount of ionic salt which results in production of a product with substantially reduced low molecular weight carbohydrate.

[0036] The salt for oxidation is selected from, but not limited to, sodium chloride, sodium bromide and potassium bromide. The amount of salt is used in the range of 0.025-0.075% w/w.

[0037] The oxidation of carbohydrate is done in a controlled manner and monitored by the qualitative analysis using the Fehling’s solution and Fourier Transform Infrared spectroscopy (FTIR).

[0038] Fehling's solution is a deep blue alkaline solution which identifies the presence of aldehydes or groups that contain any aldehyde functional group -CHO to differentiate between reducing and non-reducing sugars.

[0039] The isolation of oxidized carbohydrate is done using the organic solvent is protic solvent selected from, such as, but not limited to, methanol and isopropanol. The amount of organic solvent used in the present invention may vary depending on the amount of the oxidized carbohydrate that needs to be isolated. For instance, the amount of organic solvent used in the present invention is in a range of 1 -2 liters for isolating 100 gram of oxidized carbohydrate.

[0040] The oxidization of carbohydrates is carried out at different periods of times in order to obtain the complete oxidation of carbohydrates. Period of oxidization ranges between 2 to 7 hours; preferably between 4 to 6 hours. The complete oxidation is justified through the peaks obtained in the FTIR report ranging between 1630 cm' ¹ to 1640cm ¹ , preferably in the range of 1635-1638cm ^-1

[0041] The iron carbohydrate complex may be produced with various length of the carbohydrate moiety, preferably having the Dextrose Equivalent (DE) value ranging from 10-15. The apparent molecular weight of the carbohydrate is 5000-9000Da and preferably 6000-8000Da, and more preferably, 6500-9000Da.

[0042] In an exemplary embodiment, when carbohydrate is maltodextrin, the maltodextrin undergoes oxidation under controlled condition through electrolysis at room temperature followed by isolation, thereby reducing the need of oxidizing agent that may hinder the nascent ferric ion in further complexation reaction. The process continues until the reducing sugar concentration in the solution is in the range of 0.05 to 0.2 % which is close to nil. Samples are tested by standard methods such as Nelson-Somogyi method for monitoring the carbohydrate content which gives blue colour on detection of reducing sugar. The apparent molecular weight of the oxidized maltodextrin is found in the range of 6500-9000Da while the viscosity of the liquid oxidized carbohydrate is checked which emphasizes on the reduced impurity of the starting material. The variation in the molecular weight is minimized so as to stabilize the iron core interaction with the carbohydrate shell thus enhancing the bio-availability of the iron.

[0043] Step (B): Preparation of ferric hydroxide i. adding ferric chloride and 6001iters of Water for Injection (WFI)in a reactor to obtain a solution followed by cooling the solution at a temperature of 15 to 16°C and filtering on the celite bed to remove any sediment, checking the transmission and clarity of the solution to ensure that no insoluble matters are present emphasizing good quality raw material; ii. adding sodium carbonate solution slowly to ferric chloride solution with stirring until the pH is3.5-4.5 to obtain a precipitated mixture; iii. adding 3001iters water to the mixture and settling the ferric hydroxide precipitate for a period of 5 to 6 hours followed by decanting the upper layer of water and transferring the precipitate to the filter assembly to obtain cake of ferric hydroxide; and iv. washing the cake of ferric hydroxide thoroughly with water three to four times.

[0044] The amount of ferric chloride added in water in step (i) is in the range between 34-38%w/w.

[0045] The cake of ferric hydroxide is washed in order to obtain the sodium chloride free compound.

[0046] In an exemplary embodiment of the present invention, the obtained cake of ferric hydroxide has the amount of sodium chloride in rinsed water not more than 45ppm and the chloride content of ferric hydroxide precipitate is not more than 2.5%w/w.

[0047] Step (C): Preparation of ferric carboxy maltose i. reacting the oxidized carbohydrate obtained in step (a) in freshly prepared ferric hydroxide suspension obtained in step (b) in water under stirring at a temperature range between85 to 90°C for a period of ranges between! to 4 hours with addition of 5-10 volume of water followed by adjusting the pH and heating at 85-90°C for a period until a clear reddish black solution is obtained; and ii. settling down the reaction for 30 to 90 minutes followed by sequentially filtering the solution obtained in step (i) followed by drying to obtain the ferric carboxymaltose. [0048] The amount of oxidized carbohydrate added in the freshly prepared ferric hydroxide cake is in a ratio of 1:0.6, preferably in the ratio of 1:0.55.

[0049] During the reaction, pH is maintained at 6-7and heated at a temperature of 85 to 90° C for a period of ranging between 1 to 6 hours; preferably 2 to 4 hours, more preferably 3.5 to 4 hours. The pH is adjusted towards neutral in the range of 6-7 by adding mild mineral acid. In an exemplary embodiment, the mild mineral acid solution is selected from, but not limited to, citric acid and acetic acid.

[0050] The reaction is crucial in terms of temperature and pH. The synthesis route of the present invention is so robust that altering the pH as well as the temperature in the desired range do not alter the inherent characteristics of the carbohydrate complex i.e. the apparent average molecular weight of the product.

[0051] In an exemplary embodiment, alteration of temperature ± 5 degrees does not affect purity or molecular weight range. Similarly, alternation of pH ±2 does not affect the quality of product (Table 2).

[0052] After settling the solution obtained in step (ii) is sequentially filtered through the micron filter paper of 0.2 to 20pm, preferably filter papers are in series of 20 pm, 2.5 pm, 0.45 pm and 0.2 pm to remove any unwanted impurities, most preferably the solution is passed through 0.45 pm and 0.2 pm filter papers.

[0053] The ferric carboxymaltose after filtration is dried using an apparatus selected from, but not limited to, Vacuum Tray Dryer (VTD) and Spray dryer. The ferric carboxymaltose is preferably dried using spray dryer according to the standard procedure. The inlet temperature of the dryer is maintained at about 250-275°Cwhile the outlet temperature is about 95-115°Cso as to obtain a light brown ferric carboxymaltose powder with iron content not less than 25% and molecular weight of the powder being not less than 80kDa. [0054] Molecular weight and polydispersity index of the ferric carboxymaltose obtained is analyzed at the different time periods using the Gel Permeable Chromatography (GPC) and illustrated in Table 1.

Table 1

[0055] In an exemplary embodiment of the present invention, the molecular weight of the ferric carboxymaltose is in the range of 80kDa-200kDa, predominantly in the range of 85kDa-150kDa, while not exceedingbelowlOkDaas well as above 300kDa. Further, the polymer chains are uniformly distributed throughout the backbone of the present invention, thus the polydispersity index being not more than 2%.

[0056] Table 2 illustrates the change in the molecular weight by changing different parameters:

Table 2

[0057] In a preferable embodiment of the present invention, the ferric carboxymaltose having the physio-chemical properties characterisation for controlled release of iron in the biological system. The obtained ferric carboxymaltose is stable and has iron content preferably in the range of 30-34% w/w with the Loss on Dry (LOD) so obtained not more than 3%.

[0058] The endotoxin Limit of the ferric carboxymaltose complex is 0.35Eu/mg, which itself is concordant of the fact that additional sterilization process as a part of manufacturing is not required for Ferric carboxymaltose. The endotoxin Limit is obtained as per the BET White Paper

Endotoxin Limit: K/M, =5 Eu/kg/ 15 mg/kg

=0.3 EU/mg

[0059] The labile iron content as obtained is <0.98%, which is determined by spiking ferric carboxymaltose in serum and measuring the labile iron content spectrophotometrically by ferrozine.

Transmission Electron Microscopy Analysis of ferric carboxymaltose

[0060] The ferric carboxymaltose having an iron core surrounded by carbohydrate shell established by the Transmission Electron Microscopy. Dark, electron dense, beadlike structures confirms the cores of the iron oxide complexes, which are surrounded by a less electron dense matrix contributing to the carbohydrate fraction. TEM analysis in Figure 1 provides the clear understanding of the well dispersed, isolated iron core particles of the present invention. The mean iron core of the iron carbohydrate complex as measured by TEM Analysis is suitably not greater than about 72 nm and usually in the range of about 10 nm to no greater than 72 nm such as at least 14 nm but not much greater than 67 nm and preferably at least falls in the range of 15 nm-44 nm.

Scanning Electron Microscopy Analysis of ferric carboxymaltose

[0061] The surface characteristics of the ferric carboxymaltose are analyzed using Scanning Electron Microscopy technique. The images obtained in Figure 2a & 2brepresent flatter and smoother surface which show small and uniform structures all over the complex surface when it is observed under magnification. The images show that the iron and the surrounding carbohydrate shell exhibits uniform distribution as well as size uniformity. This itself conclude that the iron do not form clusters and properly diffuses into the system to ensure complete utilization of bio-available iron.

X-Ray diffraction Analysis of ferric carboxymaltose [0062] The crystallinity of ferric carboxymaltose is analyzed using the X-Ray diffraction. Analyzation results provided in Figure 3 illustrate multiple diffraction peaks corresponding to each diffraction planes. The major peaks at 35.606 at position of 2theta showing 100% relative intensity, while the second major peak at 33.627 at position of 2theta indicates the presence of iron oxides justifying the crystallinity of ferric carboxymaltose i.e., Akaganeite-like (P-FeOOH).

Thermogravimetric Analysis of ferric carboxymaltose

[0063] Thermogravimetric Analysis is conducted in order to identify the mass loss due to oxidative decomposition. As shown in the Figure 4, there are three distinct thermal events, which indicates at temperature 355.80°C, mass loss of 44.83% obtained.

[0064] The ferrous iron content of ferric carboxymaltose is minimized in order to reduce the oxidative stress that can be induced from ferrous iron, thus enhancing the quality of the product as a medicament for parenteral administration. The ratio of divalent to trivalent iron is found to be not more than 1% wherein ferrous content is determined titrimetrically using potassium dichromate standard solution ensuring the ferrous content to be less than 1%.

[0065] The ferric carboxymaltose complex obtained in the present invention has reduced content of dimer carbohydrate moiety to less than about 2%. This reduction in dimer content results in enhanced stability based on accelerated stability analysis as well as reduced toxicity. Further, the monomer content of ferric carboxymaltose complex is found to be practically nil thus emphasizing on the reduced toxicity.

[0066] Stability studies were carried out to observe the shelf life of ferric carboxymaltose at storage temperature of 30±2°Cand humidity 40±5%.

[0067] Table 3 illustrates stability data ferric carboxymaltose complex:

Table 3

[0068] In an embodiment, the present invention provides pharmaceutical composition comprising elemental iron of ferric carboxymaltose and water for injection in the specific range percentage.

5 [0069] In an exemplary embodiment, the pharmaceutical composition comprising 50 mg of elemental iron of ferric carboxymaltoseandl ml water for injection.

[0070] The Ferric carboxymaltose powder is present in a concentration of 50mg/ml of water.

[0071] The pharmaceutical composition may be formulated as a liquid formulation 10 selected from, but not limited to liquid formulations using isotonic solution such as NaCl solution.

[0072] The advantage of pharmaceutical composition comprising elemental iron of ferric carboxymaltose is being able to adjust the iron concentration of preferably in the range of 100-150 mg in 1 ml of water for injection for administering dose flexibility.

15 In another embodiment, the pharmaceutical composition is suitable to be dissolved in suitable liquid for preparation of a medicament that can be administered parenterally.

EXAMPLES The following examples are given by way of illustration of the working of the invention in actual practice and should not be constructed to limit the scope of the present invention in any way.

Example 1

[0073] 4001iters of WFI water was added to 100kg maltodextrin of dextrose equivalent 10-15 taken in a reactor at 25-30°C and stirred for 1 hour at the same temperature till clear aqueous solution of maltodextrin was obtained. The obtained aqueous solution of maltodextrin was oxidized by Electrolysis using an electrolyzer. To it a catalytic amount of Sodium Halide (1.2 eq.) was added and reaction was carried out at 30°C for 2 hours. 2 ml of the oxidized maltodextrin was collected in a test tube and added to 1 ml of Fehling’s solution. The same was heated in water bath, after around 10 minutes a red precipitate was observed below, showing that the oxidation was not complete.

[0074] The reaction could not be proceeded as oxidation was incomplete.

Example 2

[0075] 4001iters of WFI water was added to lOOkgmaltodextrin of dextrose equivalent 10-15 taken in a reactor at 25-30°C and stirred for 1 hour at the same temperature till clear aqueous solution of maltodextrin is obtained. The obtained aqueous solution of maltodextrin oxidized by Electrolysis using an electrolyzer. To it a catalytic amount of sodium halide (1.2 eq.) is added and reaction is carried out at 30°C for 3 hours.2 ml of the oxidized maltodextrin is collected in a test tube and added to 1 ml of Fehling’s solution. The same is heated in water bath, after around 10 minutes a red precipitate is observed below, showing that the oxidation is not complete.

[0076] The reaction could not be proceeded as oxidation was incomplete.

Example 3 [0077] 4001iters of WFI water was added to 100kg maltodextrin of dextrose equivalent 10-15 taken in a reactor at 25-30°C and stirred for 1 hour at the same temperature till clear aqueous solution of maltodextrin is obtained. The obtained aqueous solution of maltodextrin oxidized by Electrolysis using an electrolyzer. To it a catalytic amount of sodium halide (1.2 eq.) is added and reaction is carried out at 30°C for 4.5 hours. 2 ml of the oxidized maltodextrin is collected in a test tube and added to 1 ml of Fehling’s solution. The same is heated in water bath, no red precipitate was found. Finally solution is isolated in an organic solvent, preferably methanol and dried under vacuum to obtain oxidized maltodextrin in solid form.

[0078] 34% w/w ferric chloride is taken and added to 6001iters of WFI water; taken in a reactor and further the solution is cooled to 15°C. The solution transmission is checked and the clarity of the solution is justified to ensure no insoluble matters are present emphasizing good quality raw material. Sodium carbonate solution (20%w/w) is added slowly to ferric chloride solution under stirring until the pH was 4.0. 30001iters of water is further added to the mixture and the ferric hydroxide precipitate is allowed to settle for 8 hours and then decanted the upper layer of water and the precipitate is transferred to the filter assembly. The ferric hydroxide precipitate is thoroughly washed with water until the sodium chloride in the rinsed water is not more than 45ppm and the chloride content of ferric hydroxide precipitate is not more than 2.5%w/w.

[0079] A solution of oxidized maltodextrin is prepared and added to the ferric hydroxide cake obtained. The pH was adjusted to 6-7 using sodium citrate and heated to 85-90°C for 2 hours giving a reddish black colored solution of ferric carboxymaltose. The product obtained was analyzed for its molecular weight and PDI using Gel Permeable Chromatography (GPC).

Apparent molecular weight is predominantly 1 lOKDa while other less prominent peaks showing 265KDaand 7500 Da.

PDI: 1.48 Example 4

[0080] 4001iters of WFI water was added to 100kg maltodextrin of dextrose equivalent 10-15 taken in a reactor at 25-30°C and stirred for 1 hour at the same temperature till clear aqueous solution of maltodextrin is obtained. The obtained aqueous solution of maltodextrin oxidized by Electrolysis using an electrolyzer. To it a catalytic amount of sodium halide (1.2 eq.) is added and reaction is carried out at 30°C for 4.5 hours. 2 ml of the oxidized maltodextrin is collected in a test tube and added to 1 ml of Fehling’s solution. The same is heated in water bath, no red precipitate was found. Finally solution is isolated in an organic solvent, preferably methanol and dried under vacuum to obtain oxidized maltodextrin in solid form.

[0081] 34% w/w ferric chloride is taken and added to 6001iters of WFI Water; taken in a reactor and further the solution is cooled to 15°C. The solution transmission is checked and the clarity of the solution is justified to ensure no insoluble matters are present emphasizing good quality raw material. Sodium carbonate solution (20%w/w) is added slowly to ferric chloride solution under stirring until the pH was 4.0. 30001iters of water is further added to the mixture and the ferric hydroxide precipitate is allowed to settle for 8 hours and then decanted the upper layer of water and the precipitate is transferred to the filter assembly. The ferric hydroxide precipitate is thoroughly washed with water until the sodium chloride in the rinsed water is not more than 45ppm and the chloride content of ferric hydroxide precipitate is not more than 2.5%w/w.

[0082] A solution of oxidized maltodextrin is prepared and added to the ferric hydroxide cake obtained. The pH was adjusted to 6-7 using sodium citrate and heated to 85-90°C for 3 hours giving a reddish black colored solution of ferric carboxymaltose. The product obtained is analyzed for its molecular weight and PDI using Gel Permeable Chromatography (GPC).

Apparent molecular weight is predominantly 128KDa while other less prominent peaks showing 230KDa and 5000Da. PDI: 1.42

Example 5

[0083] 4001iters of WFI water was added to 100kg maltodextrin of dextrose equivalent 10-15 taken in a reactor at 25-30°C and stirred for 1 hour at the same temperature till clear aqueous solution of maltodextrin is obtained. The obtained aqueous solution of maltodextrin oxidized by Electrolysis using an Electrolyzer. To it a catalytic amount of sodium halide (1.2 eq.) is added and reaction is carried out at 30°C for 4.5 hours. 2 ml of the oxidized maltodextrin is collected in a test tube and added to 1 ml of Fehling’s solution. The same is heated in water bath, no red precipitate was found. Finally solution is isolated in an organic solvent, preferably methanol and dried under vacuum to obtain oxidized maltodextrin in solid form.

[0084] 34% w/w ferric chloride is taken and added to 6001iters of WFI water; taken in a reactor and further the solution is cooled to 15°C. The solution transmission is checked and the clarity of the solution is justified to ensure no insoluble matters are present emphasizing good quality raw material. Sodium carbonate solution (20%w/w) is added slowly to ferric chloride solution under stirring until the pH was 4.0. 30001iters of water is further added to the mixture and the ferric hydroxide precipitate is allowed to settle for 8 hours and then decanted the upper layer of water and the precipitate is transferred to the filter assembly. The ferric hydroxide precipitate is thoroughly washed with water until the sodium chloride in the rinsed water is not more than 45ppm and the chloride content of ferric hydroxide precipitate is not more than 2.5%w/w.

[0085] A solution of oxidized maltodextrin is prepared and added to the ferric hydroxide cake obtained. The pH is adjusted to 6-7 using sodium citrate and heated to 85-90°C for 3.5 hours giving a reddish black colored solution of ferric carboxymaltose. The product obtained is analyzed for its molecular weight and PDI using Gel Permeable Chromatography (GPC). Apparent molecular weight is predominantly 132KDawhile other less prominent peaks showing 265KDa and 5200 Da.

PDI: 1.25

Example 6

[0086] 4001iters of WFI water was added to 100kg maltodextrin of dextrose equivalent 10-15 taken in a reactor at 25-30°C and stirred for 1 hour at the same temperature till clear aqueous solution of maltodextrin is obtained. The obtained aqueous solution of maltodextrin oxidized by Electrolysis using an electrolyzer. To it a catalytic amount of sodium halide (1.2 eq.) is added and reaction is carried out at 30°C for 4.5 hours. 2 ml of the oxidized maltodextrin is collected in a test tube and added to 1 ml of Fehling’s solution. The same is heated in water bath, no red precipitate was found. Finally solution is isolated in an organic solvent, preferably methanol and dried under vacuum to obtain oxidized maltodextrin in solid form.

[0087] 34% w/w ferric chloride is taken and added to 6001iters of WFI water; taken in a reactor and further the solution is cooled to 15°C. The solution transmission is checked and the clarity of the solution is justified to ensure no insoluble matters are present emphasizing good quality raw material. Sodium carbonate solution (20%w/w) is added slowly to ferric chloride solution under stirring until the pH was 4.0. 30001iters of water is further added to the mixture and the ferric hydroxide precipitate is allowed to settle for 8 hours and then decanted the upper layer of water and the precipitate is transferred to the filter assembly. The ferric hydroxide precipitate is thoroughly washed with water until the sodium chloride in the rinsed water is not more than 45ppm and the chloride content of ferric hydroxide precipitate is not more than 2.5%w/w.

[0088] A solution of oxidized maltodextrin is prepared and added to the ferric hydroxide cake obtained. The pH is adjusted to 6-7 using sodium citrate and heated to 85-90°C for 4 hours giving a reddish black colored solution of ferric carboxymaltose. The product obtained is analyzed for its molecular weight and PDI using Gel Permeable Chromatography (GPC).

Apparent molecular weight is predominantly 150KDa while other less prominent peaks showing 288KDa and 3000 Da. (Mn=89820 Da)

PDI: 1.67

Solubility: 120 mg in 1 ml of water

Example 7

[0089] 4001iters of WFI water was added to 100kg maltodextrin of dextrose equivalent 10-15 taken in a reactor at 25-30°C and stirred for 1 hour at the same temperature till clear aqueous solution of maltodextrin is obtained. The obtained aqueous solution of maltodextrin oxidized by Electrolysis using an electrolyzer. To it a catalytic amount of sodium halide (1.2 eq.) is added and reaction is carried out at 30°C for 4.5 hours.2 ml of the oxidized maltodextrin is collected in a test tube and added to 1 ml of Fehling’s solution. The same is heated in water bath, no red precipitate was found. Finally solution is isolated in an organic solvent, preferably methanol and dried under vacuum to obtain oxidized maltodextrin in solid form.

[0090] 34% w/w Ferric chloride is taken and added to 6001iters of WFI water; taken in a reactor and further the solution is cooled to 15°C. The solution transmission is checked and the clarity of the solution is justified to ensure no insoluble matters are present emphasizing good quality raw material. Sodium carbonate solution (20%w/w) is added slowly to ferric chloride solution under stirring until the pH was 4.0. 30001iters of water is further added to the mixture and the ferric hydroxide precipitate is allowed to settle for 8 hours and then decanted the upper layer of water and the precipitate is transferred to the filter assembly. The ferric hydroxide precipitate is thoroughly washed with water until the sodium chloride in the rinsed water is not more than 45ppm and the chloride content of ferric hydroxide precipitate is not more than 2.5% w/w. [0091] A solution of oxidized maltodextrin is prepared and added to the ferric hydroxide cake obtained. The pH is adjusted to 8-9using sodium citrate and heated to 85-90°Cfor 4 hours giving a reddish black colored solution of ferric carboxymaltose. The product obtained is analyzed for its molecular weight and PDI using Gel Permeable Chromatography (GPC).

Apparent molecular weight is predominantly 154792 Da while other less prominent peaks showing 275KDa and 3565 Da.

PDI: 1.32

Example 8

[0092] 400 liters of WFI water was added to 100kg maltodextrin of dextrose equivalent 10-15 taken in a reactor at 25-30°C and stirred for 1 hour at the same temperature till clear aqueous solution of maltodextrin is obtained. The obtained aqueous solution of maltodextrin oxidized by Electrolysis using an electrolyzer. To it a catalytic amount of odium halide (1.2 eq.) is added and reaction is carried out at 30°C for 4.5 hours. 2 ml of the oxidized maltodextrin is collected in a test tube and added to 1 ml of Fehling’s solution. The same is heated in water bath, no red precipitate was found. Finally solution is isolated in an organic solvent, preferably methanol and dried under vacuum to obtain oxidized maltodextrin in solid form.

[0093] 34% w/w ferric chloride is taken and added to 6001iters of WFI water; taken in a reactor and further the solution is cooled to 15°C. The solution transmission is checked and the clarity of the solution is justified to ensure no insoluble matters are present emphasizing good quality raw material. Sodium carbonate solution (20%w/w) is added slowly to ferric chloride solution under stirring until the pH was 4.0. 30001iters of water is further added to the mixture and the ferric hydroxide precipitate is allowed to settle for 8 hours and then decanted the upper layer of water and the precipitate is transferred to the filter assembly. The ferric hydroxide precipitate is thoroughly washed with water until the sodium chloride in the rinsed water is not more than 45ppm and the chloride content of ferric hydroxide precipitate is not more than 2.5%w/w.

[0094] A solution of oxidized maltodextrin is prepared and added to the ferric hydroxide cake obtained. The pH is adjusted to 6-7 using sodium citrate and heated to 75-80°C for 4 hours giving a reddish black colored solution ferric carboxymaltose. The product obtained is analyzed for its molecular weight and PDI using Gel Permeable Chromatography (GPC).

Apparent molecular weight is predominantly 178922 Da while other less prominent peaks showing 215KDa and 2653 Da.

PDI: 1.44

Toxicity measurement

[0095] Ferric carboxymaltose when administered to mice in amounts of excess of 10 times, 20 times and 50 times as per the requisite dosage, no mortality is observed thus emphasizing the improved quality of product with reduced toxicity.

Hypersensitivity activity

Animals for the purpose of testing were procured from VAB Bioscience, Hyderabad. CPCSEA No: 282/Po/RcBt/S/2000/CPCSEA

[0096] Hypersensitivity activity study is carried out at two steps:

An initial test using six male and six female animals and a main test using eighteen male and eighteen female animals. No skin allergic reactions or irritation is observed in any of the test groups or control group animals at 24 hours and 48 hours post patch removal of challenge application. According to Magnusson and Kligman grading scale, none of the animals in the respective groups showed any allergic reactions, thus shows a Hypersensitivity activity rate of 0% and as per classification, it is classified as Non- allergic (Non-sensitizer) under the experimental conditions.