IT202100009857A1 - PROLONGED AND CONTROLLED RELEASE FORMULATION OF APOMORPHINE - Google Patents

Description

TITLE:

PROLONGED AND CONTROLLED RELEASE FORMULATION OF APOMORPHINE TITLE:

EXTENDED AND CONTROLLED RELEASE FORMULATION OF APOMORPHINE

FIELD OF THE INVENTION

The present invention relates to a sustained and controlled release formulation of apomorphine comprising at least one nanosponge loaded with apomorphine or a pharmaceutically acceptable salt thereof with a crosslinked polymer also known as nanosponge and an optional pharmaceutically acceptable carrier.

STATE OF ART

Apomorphine? a type of aporphine having activity? as a non-selective dopamine agonist that activates both D2-like receptors and, to a much lesser extent, D1-like receptors. It also acts as a 5-HT2 and ?-adrenergic receptor antagonist with high affinity.

Apomorphine? known as a drug useful for the treatment of Parkinson's disease and ? also known for its great susceptibility to oxidative degradation.

In fact, apomorphine as an effective agonist at both dopamine receptors in the nervous system ? It has been used for the treatment of Parkinson's disease in patients who have become resistant to or have developed adverse side effects associated with chronic levodopa therapy. Typically, due to its short duration of efficacy, apomorphine is administered by repeated subcutaneous injections or continuous parenteral infusion via a pump. These means of administration are inconvenient, in the case of subcutaneous injection, and technically difficult, in the case of pump administration, especially for Parkinson's patients whose mobility is limited. ? impaired due to the disease itself and the movements associated with chronic levodopa treatment. Apomorphine can also be administered transdermally (US Patent No.

5,562,917), intranasally (US Patent No. 5,756,483), as a topically applied gel (US Patent No. 5,939,094), or sublingually (US Patent No. 5,994,363). None of these methods allow for continuous administration over long periods of time.

Therefore, apomorphine is administered only parenterally (subcutaneous injection or infusion) due to its low bioavailability. oral and for high ?first pass? metabolism hepatic.

Many approaches have been proposed thus far to improve the therapeutic index of apomorphine, including new types of therapeutic delivery systems.

Apomorphine released from known commercial formulations has extensive first-pass hepatic metabolism leading to low bioavailability. oral and a therapeutic effect that no longer lasts? of 40 minutes.

there ? still the need? of an improved means of increasing bioavailability? and thus administration that would permit continuous dopamine agonist dosing over an extended time period of several months or more, without the adverse side effects associated with peaks and troughs in plasma levels due to discontinuous dosing, or reliance on bulky mechanical equipment such as a pump.

Therefore, the purpose of the present invention ? to provide a controlled and sustained release formulation of apomorphine so? to overcome the drawbacks of the prior art documents.

SUMMARY OF THE INVENTION

The inventors have surprisingly discovered that nanosponges can load apomorphine and allow its administration in a controlled and prolonged way. Thanks to the invention, therefore, apomorphine can brilliantly be administered by different routes, including oral, topical, parenteral and nasal, since? according to the invention the bioavailability? of apomorphine? been surprisingly increased while avoiding its degradation.

How will it be? more evident from the following, some nanostructures of nanosponges, cyclodextrin-based or dextrin-based, have shown the ability to to incorporate and protect from degradation (oxidation) apomorphine and to increase its bioavailability? and thus allow to prepare a controlled and sustained release formulation.

Therefore, the invention relates to a sustained and controlled release formulation comprising

at least one apomorphine-loaded nanosponge of

- apomorphine or a pharmaceutically acceptable salt thereof, e

- a crosslinked polymer of) a dextrin or ii) a maltodextrin derived from starch comprising amylose in the range of 25 to 50% expressed as the dry weight relative to the dry weight of the starch with a crosslinking compound selected from the group consisting of a dianhydride, sodium trimetaphosphate and citric acid; and an optional pharmaceutically acceptable vehicle.

The pharmaceutical formulation according to the invention has allowed apomorphine in nanosponges to be surprisingly released in vitro with controlled and prolonged kinetics.

In another aspect the invention relates to a method of improving the bioavailability of of apomorphine, avoiding its oxidative degradation, using the pharmaceutical formulation of the invention.

In yet another aspect the invention relates to a pharmaceutical formulation for use in the treatment of Parkinson's disease.

DESCRIPTION OF THE FIGURES:

Figure 1 shows the apomorphine calibration curve of Example 3;

Figure 2 shows the result of the evaluation of example 3 concerning the stability? apomorphine chemistry in ?-CD-PMDA nanosponges;

Figure 3 shows the graph of the in vitro nanosponge release of apomorphine ?-CD-PMDA at different pHs;

Figure 4 shows the plot of in vitro drug release kinetics of apomorphine nanosponges LC-CIT, LC-STMP and ?-CD-PMDA at pH = 6.8;

Figure 5 shows the plot of plasma concentration of apomorphine over time after drug administration in nanosponges of ?-CD-PMDA (solid line) and apomorphine solution (dashed line).

DETAILED DESCRIPTION OF THE INVENTION

Therefore, the invention relates to a sustained and controlled release formulation comprising

at least one apomorphine-loaded nanosponge of:

- apomorphine or a pharmaceutically acceptable salt thereof, e

- a crosslinked polymer of) a dextrin or ii) a maltodextrin derived from starch comprising amylose in the range of 25 to 50% expressed as the dry weight based on the dry weight of the starch with a crosslinking compound selected from the group consisting of a dianhydride, sodium trimetaphosphate and citric acid;

and a pharmaceutically acceptable optional vehicle.

In the present invention when the following terms are used:

- ?nanosponge? means the crosslinked polymer of the invention in the form of a particle. In general, the average diameter of these reticulated particles ? in the range of 1 to 1000 nm. This average diameter? a hydrodynamic diameter. Can? be determined for example by the person skilled in the art by means of laser light scattering (Laser Light Scattering). In general, these particles are insoluble in water at room temperature (20°C -25°C).

- ?Starch? classically refers to starch isolated from any suitable botanical source, by any technique well known to those skilled in the art. Isolated starch typically contains no more than of 3% of impurities?; said percentage being expressed in dry weight of impurities? relative to the total dry weight of isolated starch. These impurities? typically include proteins, colloidal matter and fibrous residues. Suitable botanical sources include for example legumes, cereals and tubers. As indicated above, a starch-based material ? a product obtained from starch. The formulation of the invention comprises apomorphine or a pharmaceutically acceptable salt.

The pharmaceutical formulation comprises a crosslinked polymer of i) a dextrin or ii) a maltodextrin derived from starch comprising amylose in the range of 25 to 50% expressed as dry weight relative to the dry weight of the starch with a crosslinking compound selected from the group consisting in a dianhydride, sodium trimetaphosphate and citric acid.

In a first preferred embodiment, the pharmaceutical formulation comprises i) a dextrin with a crosslinking compound selected from the group consisting of a dianhydride, sodium trimetaphosphate and citric acid.

The dextrin according to the invention can be a linear dextrin or a cyclodextrin. The latter? a natural or semi-synthetic cyclic oligosaccharide, which? generally biodegradable. Preferably, when the dextrin? a cyclodextrin, pu? to be ? -cyclodextrin,? ? -cyclodextrin or ? -cyclodextrins. Preferably the dextrin i) of the invention ? ?-cyclodextrin.

In another preferred embodiment the pharmaceutical formulation comprises a crosslinked polymer of ii) a starch-derived maltodextrin comprising amylose in the range of 25 to 50% expressed as dry weight relative to the dry weight of the starch with a selected crosslinking compound from the group consisting of a dianhydride, sodium trimetaphosphate and citric acid.

The expression ?maltodextrin? classically refers to starch-based material obtained by acidic and/or enzymatic hydrolysis of starch. The present invention therefore relates to a pharmaceutical formulation comprising a crosslinked polymer obtainable by reacting ii) a maltodextrin deriving from starch comprising amylose in the range from 25 to 50% expressed as dry weight with respect to the dry weight of the starch.

Preferably, the maltodextrin of the invention derives from leguminous starch. With ?legume? within the meaning of the present invention is meant any plant belonging to the Caesalpiniaceae, Mimosaceae or Papilionaceae families and in particular any plant belonging to the Papilionaceae family such as, for example, pea, bean, broad bean, broad bean, lentil, alfalfa, clover or lupin. This definition includes in particular all plants described in any of the tables contained in the article by R. HOOVER et al., 1991 (HOOVER R. (1991) ?Formulation, structure, functionality and chemical modification of leguminous starches: a review? Can. J. Physiol. Pharmacol., 69, pp.: 79-92). Preferably, the leguminous plant? selected from the group consisting of pea, bean, broad bean, broad bean and mixtures thereof.

According to a preferred and advantageous embodiment, the leguminous plant is a variety of pea or broad bean, which produces seeds containing at least 25%, preferably at least 40%, by weight of starch (dry/dry). Pi? advantageously, called leguminous plant? the pea. The term ?pea? being considered here in its most significant sense? broad and including in particular: all varieties? wild ?smooth pea? and all the varieties mutants of ?smooth pea? and ?wrinkled pea?, regardless of the uses for which said varieties are generally intended? (human consumption, animal nutrition and/or other uses).

The leguminous starch of the invention preferably has an amylose content in the range of 30% to 40%, preferably 35% to 40%, plus? preferably from 35% to 38%, these percentages being expressed as dry weight with respect to the dry weight of the starch.

Maltodextrins are conventionally obtained by acid and/or enzymatic hydrolysis of starch. Referring to regulatory status, maltodextrins have a dextrose equivalent (DE) of 1 to 20.

Preferably in the present invention the maltodextrin has a dextrose equivalent (DE) of 17 and a weight average molecular weight of about 12000 D.

Are suitable maltodextrins commercially available, for example those marketed under the name KLEPTOSE? Linecaps (LC) (ROQUETTE) or GLUCIDEX? (ROQUETTE).

The crosslinked polymer contained in the pharmaceutical formulation of the invention ? preferably of i) a ?-cyclodextrin or ii) a maltodextrin derived from a pea starch with a crosslinking compound selected from the group consisting of a dianhydride, sodium trimetaphosphate and citric acid.

The crosslinking compound ? then selected from the group consisting of a dianhydride, sodium trimetaphosphate and citric acid. Preferably, ? a dianhydride.

Among the dianhydrides, the following dianhydrides can be used in the present invention: diethylenetriaminepentaacetic dianhydride, ethylenediaminetetraacetic dianhydride, benzophenone-3,3?,4,4?-tetracarboxylic dianhydride and pyromellitic dianhydride. Pi? preferably, the crosslinking compound ? pyromellitic dianhydride.

The crosslinked polymer, that is? the nanosponge, of the pharmaceutical formulation pu? be obtained by reacting either i) a ?-cyclodextrin or ii) a maltodextrin with a crosslinking compound selected from the group consisting of a dianhydride, sodium trimetaphosphate and citric acid in a ratio in the range of compound i) or ii) to compound of crosslinking in the range of 1:2 to 1:12.

The pharmaceutical formulation of the invention can be obtained by loading apomorphine onto preformed nanosponges, generally dispersed as an aqueous nanosuspension, in the presence of suitable antioxidants and excipients. The impregnation of apomorphine can? also be obtained with the slurry method. After the loading process the aqueous nanosponge nanosuspension is freeze-dried to obtain a dry powder.

Each polymer crosslinked ? a nanosponge in the form of a solid particle. The final pharmaceutical formulation includes apomorphine loaded into the crosslinked polymeric compound, i.e. an apomorphine-loaded nanosponge having specific physical characteristics. The final pharmaceutical formulation therefore includes a plurality of of nanosponge particles loaded with apomorphine.

The final pharmaceutical formulation comprises at least one nanosponge loaded with apomorphine having specific physical characteristics.

Preferably the nanosponge loaded with apomorphine, that is? the least one nanosponge loaded with apomorphine ? choice between apomorphine-?-CD-PMDA (pyromellitic dianhydride), apomorphine-Linecaps-citric acid, apomorphine-Linecaps-STMP (sodium trimetaphosphate (STMP).

Advantageously, apomorphine-?-CD-PMDA (pyromellitic dianhydride) has an average diameter of from 150 nm to 60 nm; an index of polydispersity? from 0.1 to 0.35; and a Zeta potential from - 10 mV to - 30 mV; apomorphine-Linecaps-citric acid has an average diameter of 200 nm to 700 nm; an index of polydispersity? from 0.1 to 0.4; and a Zeta potential of -10 mV to -30 mV apomorphine-Linecaps-STMP (sodium trimetaphosphate (STMP) has an average diameter of 100 nm to 500 nm; a polydispersity index of 0.1 to 0.3; and a zeta potential of -10mV to -40mV.

The capacity? Apomorphine loading efficiency was in the range of 2% to 20% and encapsulation efficiency was in the range of 90% to 99% for all apomorphine-loaded nanosponges.

The pharmaceutical composition therefore comprises apomorphine dispersed in the crosslinked polymeric compound, i.e. an apomorphine-loaded nanosponge and an optional pharmaceutically acceptable carrier.

The latter can preferably be water or aqueous solutions or hydrogels.

The pharmaceutical formulation according to the invention has therefore allowed the apomorphine in the nanosponges to be surprisingly released in vitro with controlled and prolonged kinetics.

In another aspect the invention relates to a method of improving the bioavailability of of apomorphine, avoiding its oxidative degradation, through the use of the pharmaceutical formulation of the invention.

The invention also relates to the pharmaceutical formulation, for use as a medicine.

In yet another aspect the invention relates to a pharmaceutical formulation, for use in the treatment of Parkinson's disease.

The pharmaceutical formulation of the invention can be administered by any suitable route of administration, including systemic administration and topical administration.

Systemic administration includes oral administration, parenteral administration, transdermal administration, rectal administration and administration by inhalation.

The controlled and sustained release formulation of the invention can be administered once or according to a dosing regimen in which numerous doses are administered at varying time intervals over a given period of time as prescribed to treat disease.

The pharmaceutical formulations of the invention can be prepared and packaged in bulk form or they can be prepared and packaged in unitary pharmaceutical form. A dose of the pharmaceutical formulation contains at least one quantity? therapeutically effective than apomorphine.

The pharmaceutical formulation can also contain one or more? pharmaceutically acceptable excipients.

Conventional dosage forms include those adapted for (1) oral administration such as tablets, capsules, lozenges, pills, lozenges, powders, syrups, elixirs, suspensions, solutions, emulsions, sachets, and cachets; (2) parenteral administration such as sterile solutions, suspensions and powders for reconstitution; (3) transdermal administration such as transdermal patches; (4) rectal administration as suppositories; (5) inhalation as aerosols and solutions; and (6) topical administration such as creams, ointments, lotions, pastes, sprays and gels.

Suitable pharmaceutically acceptable excipients include the following types of excipients: diluents, fillers, binders, disintegrants, lubricants, granulating agents, glazing agents, wetting agents, suspending agents, emulsifiers, sweeteners, flavor masking agents, coloring agents, anti-caking agents, humectants, plasticizers, viscosity increasing agents, antioxidants, preservatives, stabilizers, surfactants and buffering agents. Suitable diluents and fillers include lactose, sucrose, dextrose, mannitol, sorbitol, starch, cellulose, calcium sulfate and dibasic calcium phosphate. The oral solid pharmaceutical form can also include a binder. Suitable binders include gelatin, sodium alginate, alginic acid, guar gum, povidone, and cellulose and its derivatives (e.g., microcrystalline cellulose). The oral solid pharmaceutical form can also include a disintegrant. Suitable disintegrants include crospovidone, sodium starch glycollate, alginic acid and sodium carboxymethylcellulose. The oral solid pharmaceutical form can also include a lubricant. Suitable lubricants include stearic acid, magnesium stearate, calcium stearate and talc. Suitable carriers for oral dosage forms include but are not limited to magnesium carbonate, magnesium stearate, talc, lactose, pectin, dextrin, starch, methylcellulose, sodium carboxymethylcellulose, and the like. Techniques used to prepare oral formulations are conventional mixing, granulation and compressing or filling conventional capsules.

The compounds of the present invention can also be formulated for parenteral administration with suitable carriers, including aqueous (i.e., saline, dextrose) carrier solutions and/or oily emulsions.

Will the invention be now further detailed with reference to the experimental part.

Experimental part

Example 1

1.A. Preparation of ?-CD-PMDA (pyromellitic dianhydride) nanosponge 1.A. 12.26 g of anhydrous Linecaps (Linecaps KLEPTOSE? (LC supplied by ROQUETTE) were dissolved in 50 mL of dimethyl sulfoxide in a 100 mL round bottom flask. Subsequently, 6.3 mL of triethylamine and 9, 46 g of pyromellitic dianhydride. The solution was stirred at room temperature until gelled. 24 h later, the rigid gel was broken up with a spatula, ground in a mortar and cleaned with deionized water through Buchner filtration. After a final rinse with acetone, the nanosponge was dried at room temperature.

1.B. Preparation of LC-citric nanosponge 1.B

An aqueous solution of monomers ? was prepared by dissolving 20.00 g of Linecaps (Linecaps KLEPTOSE? (LC supplied by ROQUETTE), 1.87 g of sodium hypophosphite monohydrate and 13.54 g of citric acid in 100 mL of deionized water in a 250 mL beaker. Subsequently, the solution was poured into a 20 cm diameter crystallization dish and heated in an oven for 1 h at 140°C and 4 h at 100°C, at low pressure (~20 mbar). a stiff sponge-like polymer was obtained. The polymer was immersed in deionized water to soften and then stirred. After a few minutes, stirring was stopped and the polymer was allowed to settle. The supernatant was poured off thoroughly, in order to remove the soluble and colloidal fractions of the polymer, and replaced with fresh deionized water.This cleaning cycle was repeated five-six times, until a clear and colorless supernatant was observed.Finally, the NS was obtained. was filtered in a Buchner funnel, rinsed with acetone and allowed to dry at room temperature.

1st century Nanosponge preparation of LC-STMP (sodium trimetaphosphate (STMP) 1.C

4.000 g of Linecaps (KLEPTOSE? Linecaps (LC supplied by ROQUETTE) were dissolved in 18 mL of a 1.5 M NaOH solution in a 40 mL vial. Then, 2.156 g of sodium trimetaphosphate was added. After a few minutes under stirring, a rigid polymer gel was formed. The gel was removed from the vial and ground in a mortar. Finally, the gel was washed several times with deionized water in a Buchner funnel and rinsed with acetone. After drying at room temperature, a white powder was collected.

Example 2

A) Preparation of the empty nanosponge aqueous nanosuspension

Three types of nanosponges prepared as in example 1, i.e. ?-CD-PMDA (pyromellitic dianhydride), LC-citric and LC-STMP (sodium trimetaphosphate (STMP) were used to charge apomorphine and thus prepare the final formulation.

First, a nanosuspension of each empty nanosponge (NS) prepared in Example 1? was prepared using a top-down method. For this purpose, the coarse powder of NS ? was suspended in saline solution (0.9% w/v NaCl) at a concentration of 10 mg/ml. The sample ? was homogenized using a high shear homogenizer (Ultraturrax?, IKA, Konigswinter, Germany) for 10 min at 24,000 rpm. Then, a high pressure homogenization (HPH) step? was performed using an EmulsiFlex C5 instrument (Avestin, Mannheim, Germany) for 90 min at a back pressure of 500 bar, to further reduce the size of the NS and obtain a homogeneous size distribution.

Empty NS aqueous nanosuspension ? was purified by dialysis (Spectra/Por cellulose membrane, cut-off 12,000 Da; Spectrum Laboratories, Rancho Dominguez, CA, USA) to eliminate potential synthesis residues.

B) Preparation of at least one formulation loaded with apomorphine, cio? a nanosponge loaded with apomorphine

Three types of hollow nanosponges were used to load apomorphine and then prepare the final formulation.

An empty aqueous nanosuspension for each nanosponge (?-CD-PMDA, LC-citric or LC-STMP) ? been used for loading apomorphine. After the addition of an antioxidant (i.e. 0.1% w/v ascorbic acid) and 0.05% EDTA to the nanosponge nanosuspension, ? was added a quantity? of apomorphine (usually 2 mg/mL) to each. The systems were left to stir overnight in the dark. Subsequently, the nanosuspension ? was purified by dialysis to remove unincorporated apomorphine.

In order to obtain apomorphine-loaded NS as a powder, the sample is ? was freeze-dried using a Modulyo freeze dryer (Edwards, Crawley, UK).

Example 3

Physico-chemical characterization of the pharmaceutical formulation cio? nanosponges loaded with apomorphine

The empty and apomorphine-loaded nanosponges were characterized in vitro by determining their physicochemical parameters. Average diameter, polydispersity index? and zeta potential were measured by Dynamic Light Scattering (DLS) using a 90 Plus particle sizer (USA). Measurements were performed at a fixed scattering angle of 90 ? and at 25 ?C. For analysis, the samples were diluted in filtered water (1:30 v/v). For the determination of the zeta potential, the diluted samples were placed in the electrophoretic cells where ? an electric field of about 15 V/cm was applied.

The average diameter, polydispersity index? and zeta potential value of the apomorphine-loaded nanosponges are given in Table 1.

Table 1 Physico-chemical characteristics of apomorphine-loaded nanosponge formulations

All the apomorphine-loaded nanosponges showed dimensions smaller than 600 nm and a negative zeta potential, with a value high enough to ensure stability. physics of nanosponge aqueous nanosuspensions.

Quantitative determination of apomorphine

The quantitative determination of apomorphine ? was performed by spectrophotometric analysis using a UV-Vis spectrophotometer (DU730 Beckman Coulter). The concentration of apomorphine ? was calculated using the external standard method from a calibration curve. A standard mother solution ? been prepared by dissolving a quantity? weighing of apomorphine in filtered water addition of 0.1% w/v sodium metabisulfite. So this solution? was diluted with the same solvent to give a series of standard solutions in the concentration range from 1 to 15 µg/mL. The absorbance of each standard solution ? was measured at 272 nm. The calibration curve? was obtained by plotting absorbance against the corresponding drug concentration and plotted in Figure 1. The calibration curve was linear over the concentration range of 1?15? g/mL, with a regression coefficient of 0.999.

Table 2. Apomorphine calibration curve

Stability studies in vitro

The apomorphine-loaded nanosponges prepared in Example 2 were stored at 4°C and their stability was physico-chemistry? was evaluated by measuring the concentration of apomorphine over time.

To determine the concentration of apomorphine in the nanosponges, the samples were diluted with filtered water (1:100 v/v), sonicated for 15 min and filtered through a 0.22 micron filter to separate the apomorphine from the nanosponges. The filtrate? was analyzed by spectrophotometric analysis to measure the concentration of apomorphine. The results are shown in Figure 2. The concentration of apomorphine present in the apomorphine-loaded nanosponges is not ? changed for 6 months. Example 4

Capacity determination? loading and encapsulation efficiency A quantity? weight of each nanosponge loaded with lyophilized apomorphine as prepared in example 2 and characterized in example 3 ? was suspended in filtered and sonicated water for 15 minutes. After centrifugation (20,000 rpm, 10 min), the supernatant? been filtered through a 0.22 micron filter and then analyzed by spectrophotometer to quantify the amount? of apomorphine loaded into the NS.

The capacity? of loading of each nanosponge loaded with apomorphine ? was calculated using the formula:

Capacity? loading (%) = [quantity? of loaded apomorphine/weight of apomorphine loaded NS] X 100

The encapsulation efficiency ? was calculated as follows:

Encapsulation efficiency (%) = [quantit? of apomorphine loaded/quantity? total apomorphine

The capacity? loading and encapsulation efficiency of apomorphine were determined on lyophilized samples. The drug encapsulation efficiency was more than 90% and the capacity? loading in the range of 2% to 20%.

Example 5

In vitro drug release study

In vitro release studies were performed using multi-compartment spin cells. The donor phase, consisting of 1 mL of each apomorphine-loaded nanosponge, as prepared in Example 1, is was separated from the recipient phase by a dialysis membrane (Spectra/Por cellulose membrane, cut-off 12,000 Da). The receiving phase was a phosphate buffered solution (PBS) added with 0.1% w/v sodium metabisulfite. The in vitro release ? was evaluated using PBS at three different pH values, one gastric fluid (pH = 1.2) and another intestinal fluid (pH = 6.8) and at pH = 4.0. At fixed times the receiving phase ? completely removed and replaced with fresh recipient medium. Samples taken for were analyzed using a UV-Vis spectrophotometer to determine the concentration of apomorphine.

The results are shown in Figure 3 and Figure 4. Apomorphine delivery from all nanosponges showed sustained and constant release kinetics. Example 6

In vivo oral administration of apomorphine in nanosponges

To study the oral absorption of nanocarrier-encapsulated apomorphine, an aqueous suspension of PMDA nanosponge loaded with apomorphine at a drug concentration of 1 mg/mL ? was administered directly into the duodenal lumen of fed rats via a surgically implanted duodenal cannula. Blood samples were collected, through an implanted surgical cannula inserted into the jugular vein in heparinized tubes, at the appointed time up to 24 hours after administration of the formulation. An apomorphine solution? was administered into the duodenum of rats as controls. All plasma samples were analyzed using the tuned HPLC method with a fluorometric detector.

Figure 5 reports the plasma concentration of apomorphine over time after administration of apomorphine solution and loaded apomorphine into nanosponges. The results showed that apomorphine in nanosponges showed an increase in stability and bioavailability? Oral.

Claims (15)

1. Controlled and sustained release formulation comprising at least one apomorphine-loaded nanosponge of: - apomorphine or a pharmaceutically acceptable salt thereof, e - a crosslinked polymer of) a dextrin or ii) a maltodextrin derived from starch comprising amylose in the range of 25 to 50% expressed as the dry weight relative to the dry weight of the starch with a crosslinking compound selected from the group consisting of a dianhydride, sodium trimetaphosphate and citric acid; and an optional pharmaceutically acceptable vehicle. 2. The controlled and sustained release formulation according to claim 1, wherein the pharmaceutical formulation comprises a crosslinked polymer of) a dextrin, which is? a cyclodextrin chosen from ? -cyclodextrin,? ? -cyclodextrin and ? -cyclodextrins. 3. The sustained and controlled release formulation according to claim 2, wherein the dextrin i) is ?-cyclodextrin. 4. The sustained and controlled release formulation according to claim 1, wherein the pharmaceutical formulation comprises a crosslinked polymer of ii) a maltodextrin deriving from leguminous starch. 5. The sustained and controlled release formulation according to claim 4, wherein the leguminous starch derives from a plant selected from the group consisting of pea, bean, broad bean, broad bean and mixtures thereof, plus? preferably the leguminous plant? a variety of peas or field beans. The controlled and sustained release formulation according to claim 4, wherein the leguminous starch has an amylose content in the range of 30% to 40%, preferably 35% to 40%, plus? preferably from 35% to 38%, these percentages being expressed as dry weight with respect to the dry weight of the starch. 7. The controlled and sustained release formulation according to any one of claims 1-6, wherein the crosslinking compound is? a dianhydride, preferably pyromellitic dianhydride. The sustained and controlled release formulation according to claim 1, wherein the at least one apomorphine-loaded nanosponge is choice between ?-CD-PMDA (pyromellitic dianhydride), Linecaps- citric acid, Linecaps-STMP (sodium trimetaphosphate (STMP). The controlled and sustained release formulation according to claim 8, wherein ?-CD-PMDA (pyromellitic dianhydride) has an average diameter of from 150 to 5000 nm; an index of polydispersity? from 0.10 to 0.35; and a Zeta potential of -10 to -30 mV. The controlled and sustained release formulation according to claim 8, wherein apomorphine-Linecaps-citric acid has an average diameter of from 200 nm to 700 nm; an index of polydispersity? from 0.1 to 0.4; and a Zeta potential of -10mV to -30mV. 11. The controlled and sustained release formulation according to claim 8, wherein apomorphine-Linecaps-STMP (sodium trimetaphosphate (STMP) has an average diameter of from 100 nm to 500 nm; a polydispersity index from 0.1 to 0 ,3; and a zeta potential of -10mV to -40mV. 12. The controlled and sustained release formulation according to any one of claims 1-11, wherein the ability? of loading ? between 2% and 20% and the encapsulation efficiency ? ranged from 90% to 99% for all apomorphine-loaded nanosponges. 13. A method to improve bioavailability? of apomorphine, avoiding its oxidative degradation, by using the pharmaceutical formulation according to any one of claims 1-12. 14. A pharmaceutical formulation, according to any one of claims 1-12, for use as a medicinal product. 15. A pharmaceutical formulation, according to any one of claims 1-12, for use in the treatment of Parkinson's disease.