The present invention relates to ferrous fructose-1, 6- diphosphate dihydrate, a process for the obtainment thereof, its use and a composition comprising it. .

Ferrous fructose-1, 6-diphosphate dihydrate has the following formula:

which will be herein indicated as Fe ₂ FDP ^« 2H ₂ O [(FDP representing the Fructose-1, 6-DiPhosphate anion (C ₆ Hi ₀ Oi ₂ P ₂ ^4" ) ]• Further, FDPH ₄ (CeHi ₄ Oi ₂ P ₂ ) will be herein used to indicate fructose-1, 6-diphosphate (1, 6-D-fructosediphosphoric acid).

It is known that ferrous salts are better absorbed than ferric salts and that yet they are unstable because of the oxidation of Fe ²⁺ to Fe ³⁺ and that, accordingly, they show a very short shelf-life.

JP63-227598 discloses • ferrous salts of hexose phosphate sugars, among which Fe ₂ FDP trihydrate, a process for the production thereof and their use both as an iron food supplement and for the manufacture of a medicament for the prevention and/or treatment of iron deficiency, such as, for instance, iron deficiency anemia, dietary anemia, and the like. The synthesis of the disclosed salts comprises combining an alkaline or earth-alkaline salt of the selected hexose phosphate sugar with a ferrous salt such that an insoluble salt has to be formed in order to be easily separated by the hexose phosphate sugar ferrous salt, the latter, showing an Fe ²⁺ titre lower or equal to 80% owing to the oxidation of the Fe ²⁺ , being then precipitated by the addition of a large excess of organic solvents or by freeze- drying . The hexose phosphate sugars disclosed by JP63-227598

further show a low stability in time.

It is therefore apparent the need, in the fields of dietetics and pharmaceuticals, of an iron food supplement and of a medicament for the prevention arid/or the treatment of iron deficiency which ^' show an excellent stability and shelf- life.

The applicant has surprisingly found that these needs can be advantageously overcome by administering Fe ₂ FDP*2H ₂ O.

According to a first aspect, the present invention relates to ferrous fructose-1, 6-diphosphate dihydrate (Fe ₂ FDP ^» 2H ₂ O) having the following formula:

The compound of the invention can be administered as the ^Λ active principle' of a composition which represents another aspect of the present invention and which comprises at least one dietetically and/or pharmaceutically acceptable excipient .

The composition of the invention can be prepared by processes conventional in the field such as, for instance, by mixing the active principle with said at least one excipient which can be advantageously selected ■ among either organic or inorganic, inert excipients such as, for instance, water, gelatin, arable gum, lactose, starch, cellulose, magnesium stearate, talc, vegetal oils and the like.

The composition of the invention can be administered orally, for instance under the form of pills, capsules, solutions, emulsions, suspensions, granulates and the like; also, it can also comprise further components, as it will be clearly understood by the skilled man, such as for instance, preserving agents, stabilizers, emulsifiers, buffers and the like.

Generally, the composition of the invention is administered under the form of a unitary dose comprising, for instance, 0.1 ^g of the .active principle per unitary dose.

According to another aspect, the present invention concerns the use of the compound and/or the composition as above defined for the preparation of a food supplement and/or a medicament for the prevention and/or the treatment of dietetic and/or morbid iron deficiency; in particular, for the prevention and/or the treatment of dietary anemia, sideropenia, anemia.

A further aspect of the present -invention relates to a method for the prevention and/or the treatment of dietetic and/or morbid iron deficiency in a mammal in the need thereof comprising administering a dietetically and/or therapeutically effective amount of the above defined compound and/or composition.

In particular, the mammal can be administered with a unitary dose of the compound of the invention of 0.5 to 10, preferably 1 to 2, mg/kg of body weight per day. Suitable treatments can comprise the daily administration of the above unitary dose from once to more times a day, preferably twice a day.

The dietetically and/όr pharmaceutically optimal dose can be readily determined by the man skilled in the art, depending on the iron deficiency and on the conditions (weight, age, diet, etc.) of the subject to be treated.

The above defined compound can be prepared according to a process, which is a further aspect of the present invention, comprising the steps of sequentially: a) in an inert atmosphere, solubilizing Na _x FDPHy, wherein x varies from 2 to 3 and y varies from 1 to 2, x+y being 4, and/or FDPH ₄ ; b) possibly adjusting the pH at 10-12; c) adding FeSO ₄ in a molar amount of 2:1 to 3:1 to Na _x FDPH _y and/or FDPH ₄ , possibly adjusting the pH at 6.5-7.0,

so to obtain Fe ₂ FDP » 2H ₂ O ; d) precipitating Fe ₂ FDP*2H ₂ O; e) heating the resulting mixture at 30-90 ⁰ C; f) recovering the resulting precipitate; g) drying the recovered precipitate.

Na _x FDPHy is a commercial product available on the market for instance by Biochimica Fuscama.

According to preferred embodiments, the step a) can be carried out under vacuum and/or in nitrogen atmosphere whereas the solubilizing is carried out in water.

Also preferred is to carry out the step a) in the presence of a reducing agent which can be, in particular, selected from the group consisting of sodium metabisulfite or ascorbic acid; most preferably, the reducing agent is ascorbic acid.

The reducing agent is preferably in an amount of 10-30% to the Na _x FDPH _y or FDPH ₄ moles.

In the steps b) and/or c) the pH is advantageously adjusted by a strong base, having i.e. a pK _b <5 which, in particular, can be selected from the group consisting of ammonia, sodium hydrate or potassium hydrate.

According to further preferred embodiments, the step c) is carried out at a pH of 6.8 whereas FeSO ₄ , in the same step, may be in a molar amount of 2:1 to 3:1 to Na _x FDPHy and/or FDPH ₄ .

Also preferred is to carry out the step e) at a temperature of 50°C-80°C whereas in the step f) recovering is carried out by filtering, in particular under vacuum.

Further preferred is to carry out drying in step g) till a water content of 6-10 % w/w, in particular of 7-8% w/w, for instance making reference to a thermogravimetric analysis (TGA) .

The process of the present invention allows to obtain

Fe ₂ FDP*2H ₂ O with a yield ranging from 50% to 95%; the product obtained shows an excellent stability, a long shelf-life and

an Fe ²⁺ titre higher or equal to 90%.

According to a preferred embodiment, the process of the present invention comprises solubilizing Na _x FDPH _y in degassed water, under nitrogen current, adding vitamin C and FeSO ₄ and adjusting the pH to about 6.5-7.0, f.i. by adding a strong base, such as ammonia, under stirring and nitrogen current, so to obtain Fe ₂ FDP*2H ₂ O; after heating the resulting mixture at 30-90 ⁰ C for 15-30 min., the resulting precipitate is filtered under heating, rinsed with degassed water, always in nitrogen atmosphere, and finally dried.

According to another preferred embodiment the process of the present invention comprises solubilizing Na _x FDPH _y in degassed water, under nitrogen current, adjusting the pH to about 11-12, f.i. by adding a strong base, such as sodium hydrate, under stirring, therefore obtaining a solution of Na ₄ FDP which is then added to a solution of vitamin C and FeSO ₄ , so to obtain Fe ₂ FDP«2H ₂ O; after heating the resulting mixture at 30-90 ⁰ C for 15-30 min., the resulting precipitate is filtered under heating, rinsed with degassed water and finally dried.

A further preferred embodiment of the process of the invention comprises solubilizing FDPH ₄ in degassed water, under nitrogen current, adding vitamin C and FeSO ₄ and adjusting the pH to about 6-7, f.i. by adding a strong base, such as ammonia, under stirring and nitrogen current, so to obtain Fe ₂ FDP*2H ₂ 0; after heating the resulting mixture at 40- 9O ⁰ C for 15-30 min., the resulting precipitate is filtered under heating, rinsed with degassed water, always in nitrogen atmosphere, and finally -dried. The following examples illustrate the invention without limiting it . Example 1

100 g of Na _x FDPH _y (produced by Biochimica Fuscama) ; 100 g contain 75.6 g of FDPH ₄ , equal to 0.222 mol) were dissolved in 800 ml of water, degassed and maintained under nitrogen

current. 4 g of vitamin C and 149 g of FeSO ₄ ^» 7H ₂ O (0.535 mol) were then added to the Na _x FDPHy solution.

A precipitate was observed after adding concentrated ammonia, till adjustment of the pH to 6.8, under stirring and nitrogen current, to the resulting mixture.

After heating the resulting suspension at 80 ⁰ C for 15 min., during which time the pH lowered to about 5.7, the solid was filtered under heating and rinsed with 400 ml of warm and degassed water, in nitrogen atmosphere. After drying at 100 ⁰ C under vacuum, 75 g of Fe ₂ FDP«2H ₂ O, as a grey powder, were obtained, with a yield of 70%.

The Fe ²⁺ titre, calculated by titration with a HCl solution of cerium sulphate, was found to be higher than 85%.

Example 2 To 800 ml of a water solution containing. ,75.6 g (0.222 mol) of FDPH ₄ , degassed and maintained under nitrogen current. 4 g of vitamin C and 149 g of FeSO ₄ ^« 7H ₂ O (0.535 mol) were added.

A precipitate was observed after adding concentrated ammonia, till adjustment of the pH to about 6.7-6.8, under stirring and nitrogen current, to the resulting mixture.

After heating the resulting suspension at 75 ⁰ C for about 15-30 min., the solid was filtered maintaining temperature at 75 ⁰ C and rinsed with 400 ml of warm and degassed water, in nitrogen atmosphere.

After drying at 100 ⁰ C under vacuum, 76.5 g of Fe ₂ FDP*2H ₂ O, as a grey powder, were obtained.

The Fe ²⁺ titre, calculated by titration with a HCl solution of cerium sulphate, was found to be 91.4%. Example 3

100 g of Na _x FDPH _y (produced by Biochimica Fuscama) , containing 75.6 g (0.222 mol) of FDPH ₄ , were dissolved in 300 ml of water.

Concentrated sodium hydroxide was added to the resulting solution, till complete salification to NaήFDP. The solution,

degassed and maintained under nitrogen atmosphere, was added to another solution, obtained by dissolving 4 g of vitamin C and 149 g (0.535 mol) of FeSO ₄ ^» 7H ₂ O in 450 ml of water, so that a precipitate was observed. After heating the resulting suspension at 75°C for about 15-30 min., the solid was filtered under heating and rinsed with 400 ml of warm and degassed water, in nitrogen atmosphere.

After drying at 100 ⁰ C under vacuum, 51.0 g of Fe ₂ FDP ^« 2H ₂ O, as a grey powder, were obtained.

The Fe ²⁺ titre, calculated by titration with a HCl solution of cerium sulphate, was found to be higher than 90.1%.

Example 4 (comparative) Following the protocol illustrated in the Example 5 of JP63-227598, a 5% w/w solution of FDPH ₄ (7.36 mmol) was added to a ^' solution of Ba(OH) ₂ '8 H ₂ O (4.64 g; 14.7 mmol) in water (340 ml), under N ₂ atmosphere.

The resulting mixture was vigorously shaken for 30 minutes at 25 ⁰ C. After that time, FeSO ₄ '7H ₂ O (4.08 g; 14.7 mmol) was dissolved in water (40 ml) and the resulting solution was added to the previous mixture.

A white solid, corresponding to BaSO ₄ was removed by filtration and then, ethanol (800 ml) was added. According to what described by JP63-227598, a green solid should have precipitated in a fairly good amount yet, only a negligible amount of a precipitate was indeed obtained. Remarkably, such a precipitate, adversely to what disclosed in JP63-227598, did not correspond to Fe ₂ FDP ^» 3H ₂ O. Fe ₂ FDP 2H ₂ O ANALYSIS

The following table 1 illustrates the analysis of the products obtained in the example No.2 (values are expressed as percentage) .

Table 1

Note: the amount of the total iron, determined by inductively coupled plasma mass spectrometry (ICP-MS) results to be higher than the one of Fe ²⁺ because of a minor amount of Fe ²⁺ which oxidates itself to Fe ³⁺ during the process.

The water percentage was determined as weight loss by thermogravimetric analysis, heating the compound from 5O ⁰ C to 12O ⁰ C, a temperature at which there is no degradation was observed. At the heating rate of 10°C/min, the weight loss was detected only after 105 ⁰ C. Since the thermogravimetric curve is quantitative, the calculation on the compound stoichiometry can be made:

The elementary analysis values of carbon, hydrogen and phosphor were detected on Fe ₂ FDP ^» 2H ₂ O and are illustrated in the following table 2:

Table 2

Fe ₂ FDP 2H ₂ O STABILITY

The following table 3 illustrates the measured data:

Table 3

PHARMACOLOGICAL 'TESTS

The main cause of iron deficiency has been heretofore ascribed to the depletion of the iron reserves in the. body.

Such depletion can originate itself from the chronic loss of blood or from affections of -the digesting apparatus that can reduce the absorption ^' of iron.

Iron deficiency is also common in women during pregnancy or having intense and/or frequent menstruations.

The tests carried out, and illustrated in the following, aim to compare the hematic values of serum iron (μg/ml) , of the total transferrin (mg/ml) , of ferritin (ng/ml) , of haemoglobin (g/dl) and of hematocrit (%) in 20 subjects treated with both FeSO ₄ ^« 7H ₂ O and Fe ₂ FDP»2H ₂ O, wishing to evaluate the therapeutic ability of the latter. MATERIALS AND METHODS

20 volunteers, 10 women and 10 men, 18 to 60 years old, slightly affected by sideropenia, were selected according to a random criterion and subdivided in two similar groups of 10 subjects each, identified as Group 1 and Group 2. The study was carried out in two steps, of 14 days each, denominated Step A and Step B, as illustrated in the following table 4,- in double blind and using the cross-over technique. Any administration was done twice a day, orally.

Table 4

STEP A

GROUP 1 GROUP 2

20 mg of Fe from Fe ₂ FDP •2H ₂ O 20 mg of Fe from FeSO ₄ ^« 7H ₂ O

STEP B

GROUP 1 GROUP 2

20 mg of Fe from FeSO ₄ * 7H ₂ O 20 mg of Fe from Fe ₂ FDP '2H ₂ O

Any of the treated subjects was blood drawn at the end of both steps A and B, measuring the parameters illustrated in the following tables 5-12.

TABLE 6: STEP A GROUP 1 - HEMATIC VALUES AFTER 14 DAYS OF TREATMENT WITH Fe ₂ FDP* 2H ₂ O

Volunteer 1 2 3 4 5 6 7 8 9 10 average

Serum iron μg/dl 42. 6 55.2 49.4 45. 3 52. 1 59. 4 59. 6 56.9 54.3 57.3 53 2

Total Transferrin mg/dl 262 .8 250.8 253.6 257 .4 255 .0 306 .6 278 .6 267.4 267.6 283.7 268 .4

Ferritin ng/ml 5. 3 10.8 8.4 7. 1 9. 0 64. 8 71. 8 66.6 63.3 69.5 37 7

HGB g/dl 11. 4 11.8 11.8 11. 7 11. 6 12. 6 12. 4 12.4 11.7 11.0 11 8

HCT % 35. 9 37.5 37.3 36. 1 36. 8 39. 9 39. 4 39.2 39.6 38.5 38 0

Sex F F F F F M M M M M

TABLE 8: STEP A GROUP 2 - HEMATIC VALUES AFTER 14 ] DAYS OF TREATMENT: WITH FeSO ₄ •7H ₂ O

Volunteer 11 12 13 14 15 16 17 18 19 20 average

Serum iron μg/dl 39.1 48.4 44.9 42.8 45.1 60. 5 53. 0 50.6 62. 7 51. 7 49. 9

Total Transferrin mg/dl 291.3 267.7 286.6 278.9 292.7 329 .8 283 .4 296.4 286 .8 312 .8 292 .6

Ferritin ng/ml 4.9 9.0 7.1 6.1 7.2 54. 1 58. 6 58.5 56. 5 58. 3 32. 0

HGB g/dl 11.2 11.4 10.9 11.0 10.8 12. 3 12. 0 11.5 12. 1 10. 2 11. 3

HCT % 35.9 35.1 35.2 35.4 35.7 39. 8 36. 8 36.9 39. 1 37. 1 36. 7

Sex F F F F F M M M M M

TABLE 10: STEP B GROUP 2 - HEMATIC VALUES AFTER 14 DAYS OF TREATMENT ¹ WITH Fe ₂ FDP* 2H ₂ C )

Volunteer 11 12 13 14 15 16 17 18 19 2C average

Serum iron μg/dl 48.9 57. 1 54. 8 52. 2 53.2 69. 6 56. 7 59. 7 75. 9 55. 8 58 .4

Total Transferrin mg/dl 233.0 231 .9 234 .9 223 .6 248.1 296 .8 264 .9 241 .2 237 .0 289 .6 250 .1

Ferritin ng/ml 7.0 12. 3 10. 1 8. 4 10.2 75. 7 76. 2 81. 3 80. 2 70. 5 43 .2

HGB g/dl 11.8 12. 0 11. 7 11. 9 11.4 12. 9 12. 7 12. 3 13. 1 10. 8 12 .1

HCT % 37.9 36. 9 37. 5 38. 2 38.1 41. 8 39. 2 39. 6 42. 3 39. 5 39 .1

Sex F F F F F M M M M M

TABLE 12: STEP B GROUP 1 - HEMATIC VALUES AFTER 14 I DAYS OF TREATMENT WITH FeSO ₄ •7H ₂ O

Volunteer 1 2 3 4 5 6 7 8 9 10 average

Serum iron μg/dl 46. 9 58. 0 52. 4 48. 0 54. 7 62. 4 60. 8 59. 7 57. 6 58. 7. 55 9

Total Transferrin mg/dl 238 .9 243 .9 239 .2 237 .8 242 .9 302 .0 273 .1 244 .7 252 .5 276 .8 255 .2

Ferritin ng/ml 6. 6 11. 9 9. 4 8. 1 10. 1 73. 0 78. 4 75. 3 72. 2 74. 7 42 .0

HGB g/dl 11 6 12. 1 12. 1 12 1 11. 8 12. 8 12. 6 12. 6 11. 9 11. 3 12 1

HCT % 36 7 38 5 38. 2 37 3 37. 6 40. 5 40 3 39. 9 40. 4 39. 4 38 9

Sex F F F F F M M M M M

The parameters (1- Serum iron; 2-transferrin; 3-ferritin; 4-hemoglobin; 5-hematocrit ) measured in the different steps in the two groups, are also graphically represented in figures 1-6 wherein: -Figure 1 graphically shows the average values during step A, administering Fe ₂ FDP*2H ₂ O to group 1 (i = before, ii = after) ;

-Figure 2 graphically shows the average values during step A, administering FeSO ₄ *7H ₂ O to group 2 ^■ (i = before, ii = after) ;

-Figure 3 graphically shows the percentage variations of ^■ . the parameters measured in both groups at the end of step A, after 14 days of therapy (1 = group 1, administered with Fe ₂ FDP*2H ₂ O - 2 = group 2, administered with FeSO ₄ *7H ₂ O); -Figure 4 graphically shows the average values during step B, administering Fe ₂ FDP*2H ₂ O to group 2 (i = before, ii=after) ;

-Figure 5 graphically shows the average values during step B, administering FeSO ₄ * 7H ₂ O to group 1 (i = before, ii = after) ;

-Figure 6 graphically shows the percentage variations of the parameters measured in both groups at the end of step B, after 14 days of therapy (1 = group 1, administered with FeSO ₄ *7H ₂ O - 2 = group 2, administered with Fe ₂ FDP* 2H ₂ O) ; DISCUSSION OF THE RESULTS

As illustrated in the following table 13 and by Fig. 3, at the end of step A, the therapeutic effectiveness of Fe ₂ FDP*2H ₂ O is about double than the one found for FeSO ₄ *7H ₂ O. TABLE 13

As illustrated in the following table 14 and by Fig. 6, at the end of step A, and although the percentage changes with respect to the basal values are lower, the therapeutical effectiveness of Fe ₂ FDP* 2H ₂ O is about 3-4 times than the one found for FeSO ₄ * 7H ₂ O.

TABLE 14

The variations of the five hematic parameters found between the two groups, both at end of step A and step B, are significant p<0.01.

On the basis of the results obtained, it is possible to note that Fe ₂ FDP* 2H ₂ O shows a very high oral bioavailability.

ACUTE TOXICITY The acute toxicity of Fe ₂ FDP'2H ₂ O was investigated by administering a first group of 3 female rats 2000 mg/kg of Fe ₂ FDP'2H ₂ O in a single dose, keeping them under observation for 14 days.

A second group of 3 female rats was dosed at the same level as the previous group and kept under observation for 14 days as well.

Body weight loss and reduction of the body weight gaining were observed in the animals of the group 1 during the second week of the study whereas changes in the body weight of the

animals of the second group were not remarkable throughout the 14 days.

The animals of both groups were suppressed at the end ^' of the treatment and subjected to necropsy investigation whereby no abnormalities emerged.

Neither mortality nor clinical signs were reported, for both groups, at the end of the treatment, this showing that the LD ₅₀ is higher than 2000 mg/kg and therefore the absence of any toxic effect of Fe ₂ FDP*2H ₂ θ on rat. BIOAVAILABILITY

The bioavailability of Fe ₂ FDP ^» 2H ₂ θ was investigated in comparison with the commercial product FERRO-GRAD ^® (ferrous sulphate heptahydrate) sold by Abbott SpA.

10 healthy subjects (7 men and 3 women, 30 years old, as an average), were administered for 10 days, twice a day, with FERRO-GRAD ^® ; after one week, the same group was administered for 10 days, twice a day with Fe ₂ FDP* 2H ₂ O. In both cases, the Fe ²⁺ daily dose administered to each subject amounted to 105 rng. The results are illustrated in the following tables 15 and 16 and in figures 7-8; the following abbreviations are herebelow used: AV = average; SD = standard deviation.

Table 15

Serum iron increase (μg/dl ) after the administration of FERRO-GRAD ^®

Hours 1 2 3 4 5 6

Subject

1 67 63 97 55 105 80

2 2 60 97 114 101 104

3 53 56 44 74 44 13

4 10 123 121 131 188 155

5 18 46 3 50 61 32

6 28 84 96 65 69 50

7 29 75 96 72 87 12

8 1 12 2 31 39 47

9 85 181 144 196 184 156

10 8 2 10 1 33 28

AV 30.1 70.2 71.0 78.9 91.1 67.7

SD 29.02 ^' 51.92 .51.93 55.47 55.81 54.34

Table 16

Serum iron increase (μg/dl) after the administration of

Fe ₂ FDP*2H ₂ O

Hours 1 2 3 4 5 6

Subject

1 20 100 117 125 124 71

2 24 29 150 170 152 56

3 16 29 2 18 30 18

4 37 86 95 103 85 76

5 2 65 56 72 27 1

6 27 74 139 129 149 155

7 35 36 113 37 9 75

8 57 66 3 74 63 57

9 152 65 322 290 231 207

10 37 41 70 31 77 86

AV 40.7 59.1 106.7 104.9 94.7 80.2

SD 41.79 24.52 91.40 81.07 69.28 60.65

The serum iron increase, both expressed as μg/dl and logic measured after administering FERRO-GRAD ^® and Fe ₂ FDP ^« 2H ₂ O, is also graphically represented in figures 7-8 wherein:

-Figure 7 reflects the data reported in the last two tables above and graphically shows the course of the average values of the serum iron, expressed as μg/dl, for both groups A and B, in time (h) (1 = FERRO-GRAD ^® - 2 = Fe ₂ FDP* 2H ₂ O) ; -Figure 8 graphically shows (1 = FERRO-GRAD ^® - 2 = Fe ₂ FDP^H ₂ O) the same data illustrated in the previous figure 7 yet, in logarithmic scale. It is in fact known that many biological data correspond more closely to a log normal distribution: AUC and C _ma χ tend to be skewed and their variances increase with the means. Logarithmic transformation makes the variance independent of the mean and the frequency distribution is made more symmetrical.

Further, the following tables 17-20 report all the studied parameters along with the relevant results [the following abbreviations are herebelow used: AV = average; SD = standard deviation; R = ratio between the average values calculated

for each of the measured parameters; AϋCo-6 = area under the curve in time (0-6 h) ; AUC ₀ -~ = area under the curve in time (O-∞ h) ; C _max = highest hematic concentration; t _max = time to reach the highest hematic concentration; t^ = the time to observe half the starting concentration of the compound; GA = geometric average; CC = change coefficient].- Table 17

FERRO-GRAD ^® Fe ₂ FDP •2H ₂ O

AV SD AV SD R

AUCo-6

(μg-h/dl) 412 ± 247 478 ± 287 0.86

AUC ₀ -OO 893 ± 736 973 + 699 0.92

Cmax (μg/dl) 101 ± 54 125 + 80 0.81 tmax (h) 4.4 ± 1 ^" 4.3 + 1 0..98 t _l/2 (h) 3.6 ± 3 3.4 + 2 0.94

Table 18

FERRO-GRAD ^® Fe ₂ FDP '2H ₂ O

GA GA R

AUCo-6

(μg'h/dl) 340 417 0.81

AUCo- _∞ 666 773 0.86

Cmax (μg/dl) 88 105 0.84 t _max (h) 4.3 4.2 0.98 tl/2 (h) 2.9 2.9 1

Table 19

FERRO-GRAD ^® Fe ₂ FDP«2H ₂ O

CC CC

AUCo-6

(μg'h/dl) 0.6 0.6

AUC ₀ - 0.82 0.72

Cmax (μg/dl) 0.54 0.64 tmax (h) 0.22 0.25

Table 20

FERRO-GRAD ^® Fe ₂ FDP* 2H ₂ O

Logio Log ₁₀ R

AUCo-6

(μg ^« hVdl) 9. 7 + 2.4 10.3 ± 1.7 0.94

AUC ₀ - _∞ 12 .2 + 2.7 12.7 ± 2.2 0.95

C _m ax (μg/dl) 1. 94 ± 0.2 2 ± 0.3 0.97 tmax (h) 0. 63 ± 0.2 0.62 ± 0.1 0.98 .

It can be noted that the time to reach the highest concentration (t _max ) and both the areas under the curve (AUCo- ₆ and AUC ₀ -Co) are higher in the case Fe ₂ FDP^II ₂ O whereas t^ is slightly shorter for the compound of the invention (this implying its faster disappearance in blood circulation in comparison with FERRO-GRAD ^® ) .

On the basis of the above reported data, it can be therefore noted that the release profiles of FERRO-GRAD ^® and Fe ₂ FDP* 2H ₂ O are similar and that the latter compound is better tolerated than the former one.

Also the bioavailability results to be in favour of Fe ₂ FDP* 2H ₂ O in comparison with FERRO-GRAD ^® in view of the above reported measured parameters.