WO2011000063A1

WO2011000063A1 - Aqueous solution of multicomponent inclusion compounds comprising gentamicin and iron il lactate in cy clodextrins, process for the manufacture thereof, use, method of the immunization and good health of domestic animals, kit, and pharmaceutical composition.

Info

Publication number: WO2011000063A1
Application number: PCT/BR2009/000190
Authority: WO
Inventors: LINO Antõnio Carlos SENGES
Original assignee: Schering Plough Saúde Animal Indústria E Commércio Ltda.
Priority date: 2009-06-29
Filing date: 2009-06-29
Publication date: 2011-01-06

Abstract

The present invention relates to a pharmaceutical composition, as a new aqueous solution, for oral administration of an aminoglycoside antibiotic, a donor of biochemical iron, a drug delivery system and a pharmaceutically acceptable acid or buffer. The present invention also refers to the process for the manufacture of said aqueous solution, the use of the aminogly coside antibiotic, the donor of biochemical iron, the drug delivery system and the pharmaceutically acceptable acid or buffer for preparing the aqueous solution, to the method of the immunization and good health of domestic animals and to the kit comprising the aqueous solution and instructions for using it.

Description

Title: AQUEOUS SOLUTION OF MULTICOMPONENT INCLUSION COMPOUNDS COMPRISING GENTAMICIN AND IRON Il LACTATE IN CY- CLODEXTRINS, PROCESS FOR THE MANUFACTURE THEREOF, USE, METHOD OF THE IMMUNIZATION AND GOOD HEALTH OF DOMESTIC ANIMALS, KIT, AND PHARMACEUTICAL COMPOSITION.

Field of the Invention

The present invention relates to a pharmaceutical composition, as a new aqueous solution, for oral administration of an aminoglycoside antibiotic, a donor of biochemical iron, a drug delivery system and a pharmaceuti- cally acceptable acid or buffer. The present invention also refers to the process for the manufacture of said aqueous solution, the use of the aminoglycoside antibiotic, of the donor of biochemical iron, of the drug delivery system and of the pharmaceutically acceptable acid or buffer for preparing the aqueous solution, to the method of the immunization and good health of domestic animals and to the kit comprising the aqueous solution and instructions for using it.

Background of the Invention

CDs are cyclic oligosaccharides with 6, 7 and 8 glucose units, DD- and D-CDs respectively forms a toroidal shape like a cylinder or capsu- Ie. It is generally accepted that in aqueous solutions CDs form what is called "inclusion complexes" where water molecules located within the lipophilic central cavity are replaced by a lipophilic guest molecule or a lipophilic moiety on, for example, a drug molecule. However, the hydroxy groups on the outer surface of the CD molecule are able to form hydrogen bonds with other molecules and CD can, like non-cyclic oligosaccharides and polysaccharides, form water-soluble complexes with lipophilic water-insoluble compounds. This could explain why the value of the equilibrium constant for the complex formation is sometimes concentration dependent and why their numerical value is frequently dependent on the method applied.

These kinds of products can be useful for domestic animals that need food supplement.

Multiple inclusion compounds are defined as more than one acti- ve compound inside the CD cavity forming a stable association with combinatory modes of interaction and are well-known in the state of the art.

The following documents represent the closest prior-art references to the present invention. All of them are related to D-CD containing iron or gentamicin.

BR 0303685-5: This reference discloses the stabilization of iron in D-CD at oxidation stage II.

CN 1695628: This reference discloses an orally-taken infusion of gentamicin sulfate that is prepared by mixing CD with gentamicin in boiling water. The administration of this complex to children has showed increase in the antibody production.

KR20010058414: This reference describes inclusion compounds between aminoglicosides antibodies and oligosaccharides of kitosane.

In recent works by Loftsson et al. (Self-association and cyclodex- trin solubilization of drugs. J. Pharm. Sci. 91 , 2307-2316, 2002 and Self- association of cyclodextrins and cyclodextrin complexes. J. Pharm. Sci. 93, 1091-1099, 2004) the solubilization, stabilization and self-association between CDs and drugs as cyclodextrins complexes were studied.

Nevertheless, the present formulation does not indicate an obvi- ous derivation of these works because the multiple inclusion compounds represent an unexpected result.

Different types of association of the drug-CD complex by calculating its size for the α-, β- or γ-CDs were studied. The molar ratios studied of GTM:LTT:CDs were 1 :1 :1 , 1 :1 :2, 1 :1 :3, 2:1 :3, 2:2:3 and 2:3:3, were analyzed through computer studies to indicate the best experimental conditions.

The invention disclosed herein is derived from recent studies a- bout Quantitative Structure-Activity Relationship applied to CD inclusion compounds. Multiple inclusion compounds could be an excellent alternative for the oral administration of drugs with advantages over injected and subcuta- neous treatments that cause stress to animals and are thus less effective.

Brief Description of the Drawings

Figure 1A shows a representation of possible associations 1 :1 :1 inclusion compounds between GTM : :LTT: β-CD;

Figure 1 B shows a representation of possible associations 1 :1 :3 inclusion compounds between GTM: LTT: β-CD;

Figure 2A depicts the spectra for LTT system as a function of time (0, 10 and 2Oh) and the values of ¹/2-height length for LTT peak;

Figure 2B depicts the spectra for LTT:GTM (1 :1 ) system as a function of time (0, 10 and 2Oh) and the values of ¹/2-height length for LTT peak; and

Figure 2C depicts the spectra for LTT:GTM:β-CD (1 :1 :1 ) system as a function of time (0, 10 and 2Oh) and the values of ¹/_>-height length for LTT peak.

Detailed Description of the Invention

One embodiment of the present invention refers to an aqueous solution comprising an aminoglycoside antibiotic, a donor of biochemical iron, a drug delivery system and a pharmaceutically acceptable acid or buffer, that gives to the solution a pH greater than, or equal to 3, for oral administration, wherein the aminoglycoside antibiotic is gentamicin (GTM), the donor of a biochemical iron is iron Il lactate (LTT) and the drug delivery system is a cy- clodextrin (CD), preferably β-CD, and the pharmaceutically acceptable acid or buffer is acetic acid.

A further embodiment of the present invention refers to the use of the aminoglycoside antibiotic, the donor of biochemical iron, the drug delivery system and the pharmaceutically acceptable acid or buffer, that gives to the solution a pH greater than, or equal to 3, in the preparation of an aqueous solution for the immunization and good health of domestic animals when administrated in the first months of life, wherein the aminoglycoside antibiotic is gentamicin (GTM), the donor of a biochemical iron is iron Il lactate and the drug delivery system is a cyclodextrin (CD), preferably β-CD, and the pharmaceutically acceptable acid or buffer is acetic acid.

Another embodiment of the present inventions refers to the method of the immunization and good health of domestic animals by the administration of an aqueous solution comprising the aminoglycoside antibiotic, the donor of biochemical iron, the drug delivery system and the pharmaceutically acceptable acid or buffer, that gives to the solution a pH greater than or equal to 3, in the domestic animal in its first months of life, wherein the aminoglycoside antibiotic is gentamicin (GTM), the donor of a biochemical iron is iron Il lactate and the drug delivery system is a cyclodextrin (CD), preferably β-CD, and the pharmaceutically acceptable acid or buffer is acetic acid. The use of CDs for oral administration of drugs in animals is part of state of arts in drug delivery technologie.

A further embodiment of the present inventions refers to the kit comprising an aqueous solution the aminoglycoside antibiotic, the donor of biochemical iron, the drug delivery system and the pharmaceutically acceptable acid or buffer, that gives to the solution a pH greater than or equal to 3, wherein the aminoglycoside antibiotic is gentamicin (GTM), the donor of a biochemical iron is iron Il lactate and the drug delivery system is a cyclodex- trin (CD), preferably β-CD, and the pharmaceutically acceptable acid or buffer is acetic acid; and instructions for using the kit.

The use of an oral formulation is easy to handle, and a single dose is less stressing to the animals. It is generally accepted that, in aqueous solutions, CDs form inclusion compounds wherein water molecules located within the hydrophobic central cavity are replaced with a hydrophobic guest molecule or a hydrophobic moiety of a drug molecule.

One can estimate the ability of molecules to form inclusion compounds assuming the proportionality ΔG « ΔH and applying the general thermodynamic relation:

. ΔG = -RTInK [1] therefore

ΔH ~ -RTInK [2]

Qualitatively, the measurement of ΔH (=E_binding) reflects the decrease in total energy of the system due to the formation of inclusion com- pounds.

The stability of this reaction, represented by the En_ding, can be estimated from the enthalpy of formation (ΔH_f) for all the species presented in the reaction, as follows:

. ΔH = ΔH_fs:CD - (ΔHfs + ΔH_fCD) [4]

The enthalpy of formation can be obtained from the Molecular Mechanics (MM) calculations so that the final ΔH is proportional to the stabi- lity of the inclusion compounds. For the 1 :2 stoichiometry, that the same perspective applies:

S:CD + CD → S:CD₂ [5] wherein S:CD is the low energy molecule with geometry of 1 :1 stoichiometry,

CD is the macromolecular system, and

S:CD₂ is the inclusion compound formed in the 1 :2 stoichiometry. Alternatively, we can write:

. ΔH = ΔH_fs:_CD2 - (ΔHfs.cD + ΔH_fCD) [6]

The entropy contribution is considered to be the same for the se- ries of similar molecules.

The estimation of the stability of inclusion compounds is used only as qualitative argument. For greater stoichiometries, the same arguments can be used in a stepwise condition.

MM was performed to obtain ΔH_f with different force fields and solvent treatment. AMBER94 and Optimized Potential for Liquid Simulations (OPLS) force fields were used. Solvent treatment was made with water molecules. A periodic box with same 20 angstroms in tridimensional directions as x, y and z, 20 x 20 x 20 angstroms was made with a total of 250 water molecules. Calculation in vacuum has already been performed. Computatio- nal results are summarized in Table 1.

Table 1

DH or the E_binding (kcal.mol^"1)

AMBER 94 OP LS

Va- Water Vacuum Water cuum

D-CD D-CD D-CD D-CD D-CD D-CD D-CD D-CD D-CD D-CD D-CD D-CD A* -41.74 -75.74 -44.13 -11.08 -15.31 -4.44 -4.23 -7.02 -4.55 -4.11 -5.22 -4.45B* -40.74 -70.35 -48.47 -10.21 -10.28 -8.22 -4.18 -7.13 -4.83 -4.10 -5.23 -4.33HH -11.25 -15.98 -17.63 -5.03 -15.54 -7.16 -5.16 -8.83 -6.44 -1.03 -8.34 -2.21 DH or the E_binding (kcal.mol^"1)

AMBER 94 OP LS

Va- Water Vacuum Water cuum

_**

112HT -10.49 -26.76 -18.63 -6.18 -6.02 -8.24 -6.21 -7.52 -7.90 -1.13 -7.12 -1.67 112TT* -19.27 -48.57 -18.63 -9.82 -18.12 -8.11 -8.42 -6.12 -7.32 -1.22 -6.01 -1.20

_*

113 -32.38 -80.68 -54.43 -22.17 -40.71 -34.33 -7.34 -20.64 -15.5 -1.08 -20.24 -13.31

123 -57.28 -73.29 -52.62 -24.83 -35.45 -22.76 -2.22 -18.16 -5.24 -2.43 -18.03 -2.02

223 -32.35 -78.39 -58.11 -23.88 -33.66 -28.58 -3.00 -13.08 -5.46 -1.00 -13.03 -1.11

233 -40.27 -77.18 -51.16 -21.61 -32.91 -31.05 -4.19 -7.89 +5.87 -1.21 -7.54 +10.62

(*) A and B represent the relative position towards the cavity. Figure 1 A is a relative position A of the gentamicin hydrogen atoms. Relative position B represents the CD molecule rotated in its own axis.

(^**) HH₁ HT and TT is Head-to-Head, Head-to-Tail and Tail- to-Tail annealing between two CD molecules respectively.

The best results were achieved by β-CD inclusion compounds with stoichiometries 1 :1 :1 and 1 :1 :3.

These structures are particularly interesting because one complements the other. For instance, it was observed that the same guest mole- cules migrate to the central CDs in 1 :1 :3 structures. However, stoichiometry 1 :1 :1 is stable in all cases studied. This explanation is valid considering that dynamic equilibrium may occur: in a dynamic point of view, the 1 :1 :1 and 1 :1 :3 associations seem to be complementary and to coexist. These two possible associations will be compared.

The experimental analysis of the inclusion compounds formed was made using two different techniques, Spectroscopy and Nuclear Magnetic Resonance (NMR).

First, an oriented spectroscopic experiment was performed. The oxidation product (iron III) is non-soluble, precipitates and causes the light to scatter at 500 nm. The scattering of the light at 500 nm was observed at a

BECKMAN DU-70 spectrophotometer. The absorbance measurements of the experimental result above show a unexpected behavior for the oxidation re- action from iron Il to iron 111. No oxidation was observed for the iron Il lactate used. The scanning of samples containing solutions at 1 :1 :1 , 10 mM and 1 :1 :3, 5 mM gentamicin:iron Il Iactate:β-CD from 200 to 500 nm shows only an increase of the curve at 325 nm relative to the solubilization and conse- quent growth in the concentration of iron Il lactate.

A second experimental treatment was made by NMR technique. Two different NMR approaches were used: Diffusion Ordered Spectroscopy (DOSY) and time-dependent ¹H-NMR.

The purpose of the DOSY studies was to observe the diffusion coefficients of gentamicin and iron Il lactate in the presence of β-CDs. As previously mentioned, when a molecule forms stable inclusion compounds with a macromolecule, its diffusivity is close to that expected for the macro- molecular system. The diffusion coefficient is linked to the hydrodynamic radii (H₁) of the molecule at diffusion by the Stokes-Einstein equation:

D = (KT) / 6πηr_h [7] wherein

K is the Boltzmman constant,

T is the temperature at Kelvin scale,

η is the viscosity of the solution, and

r_h can be expressed in angstroms.

¹H and DOSY experiments were carried out on a Varian Inova 500AS spectrometer operating with a magnetic field at 9.24 Tesla and 499.78 MHz for ¹H, at 298K.

The samples (5mM) were prepared in D₂O (600 μL) with iron II lactate, gentamicin and β-CD at different molar ratios. The spectrum is referenced using the water residual peak. The data was processed using the MestreC 1 D program.

The DOSY experiments were carried out using the BPPSTE (Bipolar Pulse Pairs Stimulated Echo) method. The duration of the total diffusi- on-phase encoding gradient pulse was 2 ms, the diffusion delay was 0.05 s and the minimum gradient strength was set to 0.3 Gauss/cm. The samples were made at 5 mM concentration for iron Il lactate (LTT), gentamicin (GTM), β-CD and solutions of 1 :1 LTTGTM, 1 :1 :1 LTT:GTM:β-CD and 1 :1 :3 LTT:GTM:β-CD. Table 2 shows self-diffusion, which is characteristic of molecules alone (D_free) and in different conditions 1 :1 , 1 :1 :1 and 1 :1 :3 LTT: GTM: β- CD (Dobs).

Table 2

Diffusion Coefficients (10 ^'5cm ².s ^'1)

Dfree Di:1 D-|_:1_:1 Di_:-| _:3

LTT 0.688±0.025 0.313+0.031 0.254±0.027 ND

GTM 0.315±0.040 0.243+0.010 0.225±0.002 ND

D-CD 0.184±0.002 0.181+0.001 0.178±0.003

The results show a decrease in diffusion coefficient values when LTT and GTM were in the presence of cyclodextrin. For LTT, the diffusion coefficients range from 0.688.10^"5 cm²s^"1 in water to 0.313.10^"5 cmV¹ in the 1 :1 GTM±TT system and to 0.254.10^"5 cmV¹ in the 1 :1 :1 GTM:LTT:β-CD system. These results indicate that LTT interacts with GTM molecule forming a co-solute and that, in the presence of cyclodextrin, formed an inclusion complex (as proposed by Molecular Mechanics calculation). The GTM presents similar results (Table 2). The diffusion coefficient for LTT:GTM (1 :1 ) presented an interesting result, as the system LTT:GTM shows a diffusion coefficient equal to that of GTM alone, indicating that LTT interacts with the GTM molecule and that the coefficient diffusion was driven by the GTM molecule properties.

The diffusion coefficient for β-CD in GTM:LTT:β-CD systems at molar ratios of 1 :1 :1 and 1 :1 :3 ranges from 0.184.10^'5 cmV¹ (in water) to 0.181.10^"5 cmV and 0.178.10^'5 cmV, respectively, probably because a small part of the 1 :1 :3 association is stable and because the other form, 1 :1 :1 , is in dynamic equilibrium.

DOSY NMR results highlight two important details for the molecular interactions involved in the formation of inclusion compounds:

i. The higher interaction between iron Il lactate and gentamicin molecules can explain, in part, the migration of the same guest molecules to only one cavity (Figures 1A and 1 B).

ii. The decrease of the diffusion coefficients for the guest molecules is close to the β-CD diffusion coefficients, when inclusion compounds are formed. This is irrefutable proof of the stable formation of inclusion com- pounds.

Time-dependent ¹H-NMR was used to identify the correlation between the molecular interactions and the stabilization of the inclusion compounds. Enlargement of half-height peaks in NMR spectrum can indicate interaction between molecules in the system.

The LTT, GTM and β-CD hydrogen atoms in a NMR spectrum were measured as a function of time (0-20 h) at different molar ratios 5 mM for LTT, LTT:GTM (1 :1) and LTT:GTM:β-CD (1 :1 :1 ).

Figures 2A, 2B and 2C showed the spectra for a) LTT, b) LTT:GTM (1 :1 ) and c) LTT:GTM:β-CD (1 :1 :1 ) systems, respectively, as a function of time (0, 10 and 2Oh) and the values of ¹/2-height length for LTT peak. These results showed that the LTT changes the length of ¹/2-height peak in the presence of GTM and the GTM:β-CD system that was indicating an interaction between these molecules. For the LTT:GTM:β-CD (1 :1 :1 ) system, the spectrum is stabilized during approximately 5h.

It has also been found that 1 :1 :1 and 1 :1 :3 of GTM:LTT:β-CD is not only very soluble but also very stable in aqueous solution.

The complex formed between a molecule of GTM and LTT using one or three molecules of β-CD is novel and constitutes a further aspect of the present invention.

A further embodiment of the present invention refers to the process of manufacturing the aqueous solution and to the aqueous solution obtainable by said process.

The process for manufacturing the aqueous solution comprises the steps of grounding EDTA, methylpareben, propylparaben, sodium bisul- phite, gentamicin and β-CD. After grinding, acetic acid and sorbitol are added, followed by the addition of iron Il lactate and deionized MiIIiQ water. The final mixture is homogenized with a dissolution procedure. The 1 :1 :1 is con- sidered the best formulation because of the presence of solids in the 1 :1 :3 formulation, but with vigorous stirring, the solids can be dissolved.

The industrial scale manufacturing process is similar with regard to the sequence of addition. In large-scale production, the first step - the ad- dition of solid compounds - must be carried out in a spray drying equipment; the acetic acid and sorbitol must be added in an addition reactor and the final solution must be stirred at least 24 hours after final solubilization. The compounds maintain the proportionality.

The solution can be purified by ultrafiltration (0.22 μm membrane filter) or autoclaved (optional procedure) according to usual techniques and then stored. This solution may be divided into mono- or multidose containers.

The solution obtained by the present process can be used in the form of a dosage unit containing an effective amount of the active compound (or substance).

In another aspect of the present invention, an oral pharmaceutical composition is provided in dosage units comprising an aqueous solution.

The proportionality between Gentamicimlron Il Lactate:CD is defined as 1 :1 :1 and 1 :1 :3. In the first case, a mass of at least 5.000 mg of gen- tamicin sulfate is added to at least 2.500 mg of iron Il lactate and at least 12.20 mg for D-CD per dosage. In the second case, a mass of at least 36.60 mg must be used. The important in this point is to observe that any amount of ingredients can be used provided the proportionality between them is kept.

Alternatively, a formulation using D- or D-CD can be used. In this case, ratios 1 :1 :1 and 1 :1 :3 are obtained with i) at least 10.45 mg for 1 :1 :1 and at least 31.35 mg for 1 :1 :3 using D-CD and ii) at least 13.94 mg for 1 :1 :1 and at least 41.76 mg for 1 :1 :3 using D-CD per dosage.

The solution and the composition of the invention can optionally comprise sweeteners or flavoring agents to enhance its taste.

Examples of basic formulations mentioned herein is described in details above.

Particularly advantageous pharmaceutical compositions are indicated in Table 3. Table 3

Pharmaceutical composition (1 ml_) 1 :1 :1 1 :1 :3

Gentamicin sulfate 5.000 mg 5.000 mg methyl paraben 1.300 mg 1.300 mg

Iron Il Lactate 2.500 mg 2.500 mg

D-CD 12.20 mg 36.60 mg propylparaben 0.200 mg 0.200 mg

Sodium Bisulphite 2.000 mg 2.000 mg

EDTA 4.000 mg 4.000 mg

Acetic acid 3.000 mg 3.000 mg

MiIIi-Q distilled water 1.000 m!_ 1.000 mL

Alternative formulations comprising D-CD are indicate in Table 4.

Table 4

Pharmaceutical composition (1mL) 1 :1 :1 1 :1 :3

Gentamicin sulfate 5.000 mg 5.000 mg methyl paraben 1.300 mg 1.300 mg

Iron II Lactate 2.500 mg 2.500 mg

D-CD 10.45 mg 31.35 mg propylparaben 0.200 mg 0.200 mg

Sodium Bisulphite 2.000 mg 2.000 mg

EDTA 4.000 mg 4.000 mg

Acetic acid 3.000 mg 3.000 mg

MiIIi-Q distilled water 1.000 mL 1.000 mL

In addition, formulations comprising D-CD are indicate in Table 5.

Table 5

Pharmaceutical composition (1 mL) 1 :1 :1 1 :1 :3

Gentamicin sulfate 5.000 mg 5.000 mg methyl paraben 1.300 mg 1.300 mg

Iron Il Lactate 2.500 mg 2.500 mg

D-CD 13.940 mg 41.760 mg propylparaben 0.200 mg 0.200 mg

Sodium Bisulphite 2.000 mg 2.000 mg

EDTA 4.000 mg 4.000 mg Acetic acid 3.000 mg 3.000 mg

MiIIi-Q distilled water 1.000 ml_ 1.000 mL

As can be seen, the amount of CD used at 1 mL of solution is 12.20 to 36.60 mg of β-CD, 10.45 to 31.35 mg of α-CD or 13.94 to41.76 mg of Y-CD.

Whether or not submitted to autoclave, the pharmaceutical com- position of the present invention proved to be very stable on storage, under the following conditions:

- Temperature from 8⁰C to 5O⁰C

- Storage for 6 months at controlled temperature and humidity. The composition of the invention in dosage units can be packa- ged according to the usual practice, for example, in glass, polycarbonate, polyvinyl chloride, polyethylene or polypropylene vials with a suitable cap forming a functional pump for oral administration.

The following examples are merely for demonstrating the feasibility of the object of the invention, and cannot be interpreted as a restriction of the scope of protection.

EXAMPLES

Example 1 : Preparation of a Solution of Gentamicin at 5.000 mg/mL content D-CD.

210.0 mg of gentamicin sulfate (corresponding to 200.0 mg of gentamicin free base), 0.500 g to 1.500 g of β-CD (CycloLab, in accordance with the tests of European and American pharmacopoeias), 0.100 g of iron Il lactate, 8.000 mg of nipasol and 52.00 mg of nipagin, 1.000 g of sodium bi- sulphate and 2.000 g of EDTA in 40.00 mL of water are mixed together at room temperature, in the following order: EDTA, nipagin (methylpareben), nipasol (propylparaben), sodium bisulphite, gentamicin and β-CD; after grinding, acetic acid and sorbitol are added, followed by the addition of iron Il lactate and deionized MiIIiQ water. Whether or not in a protective atmosphere (with nitrogen), they are stirred until complete dissolution.

Example 2: Preparation of a Solution of Gentamicin at 5.000 mg/mL content D-CD. 210.0 mg of gentamicin sulfate (corresponding to 200.0 mg of gentamicin free base), 0.428 g to 1.285 g of D-CD (CycloLab, in accordance with the tests of European and American pharmacopoeias), 0.100 g of iron Il lactate, 8.000 mg of nipasol and 52.00 mg of nipagin, 1.000 g of sodium bi- sulphate and 2.000 g of EDTA in 40.00 ml_ of water are mixed together at room temperature, in the following order: EDTA, nipagin (methylpareben), nipasol (propylparaben), sodium bisulphite, gentamicin and D-CD; after grinding, acetic acid and sorbitol are added, followed by the addition of iron Il lactate and deionized MiIIiQ water. Whether or not in a protective atmosphere (with nitrogen), they are stirred until complete dissolution.

Example 3: Preparation of a Solution of Gentamicin at 5.000 mg/mL content D-CD.

210.0 mg of gentamicin sulfate (corresponding to 200.0 mg of gentamicin free base), 0.571 g to 1.714 g of D-CD (CycloLab, in accordance with the tests of European and American pharmacopoeias), 0.100 g of iron Il lactate, 8.000 mg of nipasol and 52.00 mg of nipagin, 1.000 g of sodium bi- sulphate and 2.000 g of EDTA in 40.00 mL of water are mixed together at room temperature, in the following order: EDTA, nipagin (methylpareben), nipasol (propylparaben), sodium bisulphite, gentamicin and D-CD; after grin- ding, acetic acid and sorbitol are added, followed by the addition of iron Il lactate and deionized MiIIiQ water. Whether or not in a protective atmosphere (with nitrogen), they are stirred until complete dissolution.

The aqueous solution are useful for domestic or non-domestic animals that need food supplement. However, since the effects in animal body is in molecular scale it is not possible to distinguish differences between the animals.

Claims

1. An aqueous solution, characterized by comprising an aminoglycoside antibiotic, a donor of biochemical iron, a drug delivery system and a pharmaceutically acceptable acid or buffer.

2. The aqueous solution according to claim 1 , characterized by comprising at 1 mL of solution, at least 5.000 mg of the aminoglycoside antibiotic, at least 2.500 mg of the donor of biochemical iron and proportions of the drug delivery system in the stoichometries 1 :1 :1 and 1 :1 :3.

3. The aqueous solution according to claim 1 or 2, characterized in that the aminoglycoside antibiotic is gentamicin (GTM), the donor of a biochemical iron is iron Il lactate and the drug delivery system is a cyclodextrin (CD).

4. The aqueous solution according to claim 3, characterized in that the cyclodextrin is selected from α-, β- and γ-CD.

5. The aqueous solution according to claim 4, characterized in that the amount of CD used at 1 ml_ of solution is 12.20 to 36.60 mg of β-CD, 10.45 to 31.35 mg of α-CD or 13.94 to 41.76 mg of γ-CD.

6. The aqueous solution according to claim 5, characterized by comprising at 1 ml_ of solution at least 5.000 mg of GTM, at least 2.500 mg of LTT and 12.20 mg of β -CD.

7. The aqueous solution according to any one of claims 1 to 6, characterized in that the pharmaceutically acceptable acid or buffer gives to the solution a pH greater than, or equal to 3.

8. The aqueous solution according to claim 7, characterized in that the pharmaceutically acceptable acid or buffer is acetic acid.

9. The aqueous solution according to any one of claims 1 to 8, characterized by the stabilization of iron II, aminoglycoside antibiotic and β - CD in water solutions at the molar ratios of 1 :1 :1 and 1 :1 :3, at concentrations of 10 mM and 5 mM for aminoglycoside antibiotic.

10. The aqueous solution according to any one of claims 1 to 9, characterized by being for use in the immunization and good health of domestic animals when administrated in the first months of life.

11. A process for manufacturing an aqueous solution, as defined in any one of claims 1 to 10, characterized in that:

• the solutions of EDTA, methylpareben, propylparaben, sodium bisulphite, gentamicin and β -CD are added in a mixing reactor in this order;

• the mixture is grounded;

• acetic acid and sorbitol are added;

• iron Il lactate and deionized MiIIiQ water are added; and

• the resultant mixture is stirred until complete dissolution.

12. An aqueous solution, characterized by being obtainable by the process, as defined in claim 11.

13. An use of an aminoglycoside antibiotic, a donor of biochemical iron, a drug delivery system and a pharmaceutically acceptable acid or buffer, characterized by being for preparing an aqueous solution, as defined in any of claims 1 to 10 and 12, for the immunization and good health of do- mestic animals when administrated in the first months of life.

14. A method for immunization and good health of domestic animals, characterized by administrating an aqueous solution, as defined in any of claims 1 to 10 and 12, in the domestic animal in its first months of life.

15. Kit, characterized by comprising an aqueous solution, as defi- ned in any of claims 1 to 10 and 12, and instructions for use.

16. A pharmaceutical composition, characterized by comprising the aqueous solution, as defined in any of claims 1 to 10 and 12.

17. A pharmaceutical composition according to claim 16, characterized by being in dosage units.

18. A pharmaceutical composition according to claim 16 and 17, characterized by further comprising sweeteners or flavoring agents.