Aqueous bumetanide-containing liquid

Abstract

The invention relates to an aqueous bumetanide-containing liquid comprising: • 0.1-5 wt.% bumetanide; • 0.1-10 wt.% of amine-functional polymer; and • 65-99 wt.% water; wherein the aqueous bumetanide-containing liquid has a pH at 25°C in the range of 4.5 to 8.0. The aqueous bumetanide-containing liquid of the present invention achieves excellent bioavailability upon transmucosal administration. In addition, diuresis is achieved much faster by transmucosal administration of the aqueous bumetanide-containing liquid than by oral administration of known oral bumetanide formulations.

Description

[0001] AQUEOUS BUMETANIDE-CONTAINING LIQUID

[0002] TECHNICAL FIELD OF THE INVENTION

[0003] The present invention relates to an aqueous liquid comprising bumetanide, amine-functional polymer and water, the bumetanide-containing liquid having a pH at 25°C in the range of 5 to 8.

[0004] The invention further relates to a spraying device comprising a container holding said aqueous bumetanide-containing liquid and to the use of the aqueous bumetanide-containing liquid in medical treatment comprising transmucosal administration of the liquid.

[0005] BACKGROUND OF THE INVENTION

[0006] Bumetanide is a medication used to treat edema caused by conditions such as heart failure, liver failure, or kidney problems. Administration of bumetanide can lessen symptoms such as shortness of breath and swelling in arms, legs, and abdomen. Bumetanide is a diuretic that causes patients to produce more urine and to get rid of (extra) water and salt. Bumetanide is taken orally, or by injection into a vein or muscle. Effects generally begin within an hour and lasts for about six hours. Bumetanide has a very low water solubility (26 mg / L at 25°C). Bumetanide is a diprotic acid with a pKaiof 3.6 and a Pka2 of 7.7.

[0007] Transmucosal administration of drugs has the potential to improve therapy efficacy by increasing patient’s treatment adherence and reducing side effects compared to, for instance, intravenous and oral administration.

[0008] In the past century, the use of intranasally administered drugs was mainly restricted to treating topical symptoms of seasonal rhinitis or infectious diseases of the respiratory tract, for example. It was only at the end of the twentieth century that nasal delivery became more prominent as an alternative route for systemic therapy. The surface of the nasal mucosa in humans is around 150 cm2. This tissue is well supplied by blood vessels in extreme close proximity to the mucosal surface (blood vessels and mucosal surface are separated by only one mucosal cell layer), which allows for a rapid absorption and high systemic blood levels of the drug, while avoiding the first pass metabolism.

[0009] Despite the increasing number of approved nasal formulations, the development of new formulations remains challenging, especially for formulations based on hydrophobic drugs, i.e. drugs having a very low water solubility. This is because (i) water is the preferred solvent, (ii) the amount of formulation that can be administered intranasally is limited and (iii) many pharmaceutical excipients cause irritation.

[0010] WO 2021 / 113775 describes compositions for intranasal, sublingual, and subcutaneous administration of bumetanide for the treatment of subjects suffering from edema refractory to oral diuretics.

[0011] WO 2023 / 285009 describes an aqueous bumetanide-containing liquid comprising:

[0012] • 0.3-5 wt.% bumetanide;

[0013] • 2-30 wt.% of a non-ionic surfactant having a H LB of more than 10; and

[0014] • 65-94 wt.% water; wherein the liquid has a pH at 25°C in the range of 5-9 and wherein each of the bumetanide and the non-ionic surfactant is dissolved and / or contained in colloidal particles having a diameter of less than 50 nm.

[0015] Collado-Gonzalez et al. (Interaction Between Chitosan and Mucin: Fundamentals and Applications, Biomimetics 2019, 4, 32; doi:10.3390 / biomimetics4020032) mentions that chitosan is nontoxic, mucoadhesive that can be used for load and transport drugs.

[0016] SUMMARY OF THE INVENTION

[0017] The inventors have developed an aqueous bumetanide-containing liquid that can suitably be used for transmucosal administration of bumetanide, said aqueous liquid comprising:

[0018] • 0.1-5 wt.% bumetanide;

[0019] • 0.1-10 wt.% of amine-functional polymer; and

[0020] • 65-99 wt.% water; wherein the aqueous bumetanide-containing liquid has a pH at 25°C in the range of 4.5 to 8.0.

[0021] The aqueous bumetanide-containing liquid of the present invention achieves excellent bioavailability upon transmucosal administration. In addition, diuresis is achieved much faster by transmucosal administration of the aqueous bumetanide-containing liquid of the present invention than by oral administration of known oral bumetanide formulations.

[0022] The bumetanide-containing aqueous liquid of the present invention offers the advantage that it can accommodate relatively high concentrations of bumetanide. In comparison to e.g. emulsions, the aqueous liquid has excellent storage stability across a broad temperature range. Furthermore, the liquid is easy to manufacture and enables uniform and accurate dosing. The aqueous bumetanide-containing liquid can be administered transmucosally without causing irritation, e.g. stinging or itching.

[0023] Transmucosal administration of bumetanide represents an advantageous solution for patients experiencing impaired gastrointestinal absorption due to edema as a result from decompensated heart failure . This scenario normally requires high dosages of oral diuretics, which further increases the strain on the kidneys and liver.

[0024] The invention also provides a spraying device comprising:

[0025] • a container holding the aqueous bumetanide-containing liquid of the present invention,

[0026] • a nozzle in fluid connection with the container, and

[0027] • a metered dose pump configured to create a flow of the aqueous bumetanide- containing liquid through the nozzle upon activation.

[0028] Another aspect of the invention relates to the administration of the aqueous bumetanide- containing liquid of the present invention to prevent or treat edema, hyperkalemia, epileptic seizures, autism, hypertension, renal insufficiency, nephrotic syndrome, liver cirrhosis and / or heart failure.

[0029] DETAILED DESCRIPTION OF THE INVENTION

[0030] A first aspect of the invention relates to an aqueous bumetanide-containing liquid comprising:

[0031] • 0.1-5 wt.% bumetanide;

[0032] • 0.1-10 wt.% of amine-functional polymer; and

[0033] • 65-99 wt.% water; wherein the aqueous bumetanide-containing liquid has a pH at 25°C in the range of 4.5 to 8.0.

[0034] The term “polymer” as used herein refers to a substance comprising at least 10 covalently bound repeating subunits. Examples of such repeating subunits include monosaccharides, amino acids and synthetic monomers.

[0035] The term “amine-functional polymer” as used herein refers to a polymer that contains multiple amine groups that can become positively charged in aqueous environment through protonation. These amine groups can be primary, secondary and or tertiary amine groups. The term “transmucosal administration” as used herein refers to a non-invasive route of systemic drug delivery that bypasses the gastrointestinal tract. Examples of transmucosal administration routes include intranasal, intra-oral, pulmonary and ocular administration.

[0036] The term “or” as used herein should be construed as “and / or”, unless specified otherwise.

[0037] The term “a” or “an” as used herein is defined as “at least one” unless specified otherwise.

[0038] Numerical ranges expressed in the format “from x to y” are understood to include x and y.

[0039] Whenever components A and B are said to be present in a weight ratio of x:y, what is meant is that the concentration of component A in wt.% divided by the concentration of component B in wt.% equals x:y.

[0040] Ratios mentioned herein are based on weight / weight, unless indicated otherwise. Similarly, all percentages are percentages by weight (w / w) unless otherwise indicated.

[0041] When multiple preferred ranges are described in the format “from x to y” for a specific feature, it should be understood that all ranges combining the different endpoints are also contemplated.

[0042] If, for a particular component, a range of 0% to y% or less than y% is recited, said ingredient may be absent.

[0043] The aqueous bumetanide-containing liquid of the present invention preferably comprises 0.25- 4 wt.%, more preferably 0.35-3 wt.% and most preferably, 0.5-2.0 wt.% of bumetanide.

[0044] According to a particularly preferred embodiment, the bumetanide is fully dissolved in the aqueous liquid.

[0045] The concentration of amine-functional polymer in the aqueous bumetanide-containing liquid preferably is in the range of 0.10-4 wt.%, more preferably in the range of 0.2-2 wt.% and most preferably in the range 0.25-1.5 wt.% of the amine-functional polymer.

[0046] The amine-functional polymer that is employed in accordance with the present invention preferably comprises at least 1 amine group per 1 ,000 Da, more preferably at least 1 amine group per 600 Da, most preferably 1-3 amine groups per 400 Da. Although the inventors do not wish to be bound by theory, it is believed that the amine- functional polymer is particularly effective in enhancing transmucosal uptake of the bumetanide from the aqueous bumetanide-containing liquid if the polymer carries a net positive charge. Such a net positive charge is achieved by lowering the pH of the aqueous bumetanide-containing liquid to a level at which the amine groups of the amine-functional polymer become positively charged.

[0047] In a preferred embodiment, the amine-functional polymer that is present in the aqueous bumetanide-containing liquid of the present invention has a pKathat is not more than 0.5 pH points lower than the pH of the aqueous bumetanide-containing liquid. More preferably, the pKaof the amine-functional polymer exceeds the pH of the aqueous bumetanide-containing liquid. The pKaof the amine-functional polymer is determined at a temperature of 20°C and at the concentration at which the amine-functional polymer is present in the bumetanide- containing aqueous liquid. The pKaof the amine-functional polymer may suitably be determined by the method that is described by Sorlier et al. (Relation between the Degree of Acetylation and the Electrostatic Properties of Chitin and Chitosan, Biomacromolecules (2001 ) 2, 765-772). According to a particularly preferred embodiment, the amine-functional polymer has a pKathat exceeds the pH of the aqueous bumetanide-containing liquid by at least 0.1 pH points, more preferably by 0.2-3 pH points and most preferably by 0.3-2 pH points.

[0048] According to another preferred embodiment, the amine-functional polymer is positively charged at the pH of the aqueous bumetanide-containing liquid at 20 °C. To determine if a polymer has a positive charge at the pH of aqueous bumetanide-containing liquid, the polymer is dispersed in distilled water of 20 °C at a pH equal to the pH of the aqueous bumetanide- containing liquid (using NaOH and HCI to adjust pH), following which the charge of the polymer is determined. This may suitably by colloidal titration using a Charge Analyzing System (CAS) supplied by AFG Analytic GmbH and using 0.001 N poly-diallyl-dimethyl-ammonium chlorides (PDADMAC) as titrant.

[0049] The amine-functional polymer employed in accordance with the present invention is preferably selected from chitosan, quaternised chitosan, carboxymethyl chitosan, amino-functionalised dextran, amino-functionalised cellulose, amino-functionalised polyoxazoline, aminofunctionalised cyclodextrin, protamine, gelatine, poly-L(lysine), poly(ethyleneimine), poly(amidoamine), poly(amino-co-ester), poly[2-(N,N-dimethylamino)ethyl methacrylate] and combinations thereof. More preferably, the amine-functional polymer is selected from chitosan, quaternised chitosan, carboxymethyl chitosan, amino-functionalised dextran, amino- functionalised cellulose, protamine, gelatine and combinations thereof. More preferably, the amine-functional polymer is selected from chitosan, quaternised chitosan, aminofunctionalised dextran, protamine and combinations thereof. Most preferably, the amine- functional polymer is chitosan.

[0050] The amine-functional polymer preferably has a molecular weight of at least 1 kDa, more preferably of 2 to 2,000 kDa and most preferably of 5 to 1 ,500 kDa.

[0051] Bumetanide and the amine-functional polymer are preferably present in the aqueous bumetanide-containing liquid a weight ratio bumetanide : amine-functional polymer of 0.4 to 8, more preferably a weight ratio of 0.6 to 6, most preferably in a weight ratio of 0.8 to 5.

[0052] According to a particularly preferred embodiment, the amine-functional polymer has a cationic charge density of at least 1 meq / g at the pH of the liquid at 25°C. More preferably, the amine- functional polymer has a cationic charge density of 2-8 meq / g at the pH of the liquid at 25°C. Most preferably, the amine-functional polymer has a cationic charge density of 3-6 meq / g at the pH of the liquid at 25°C. To determine if a polymer has a positive charge at the pH of aqueous bumetanide-containing liquid, the polymer is dispersed in distilled water of 25 °C at a pH equal to the pH of the aqueous bumetanide-containing liquid (using NaOH and HCI to adjust pH), following which the charge of the polymer is determined. To determine the charge density of a polymer, the polymer is dispersed in distilled water of 25 °C, following which the charge of the polymer is determined by colloidal titration using a Charge Analyzing System (CAS) supplied by AFG Analytic GmbH and using 0.001 N poly-diallyl-dimethyl-ammonium chlorides (PDADMAC) as titrant.

[0053] The water content of the aqueous bumetanide-containing liquid preferably is in the range of 75.0-98.5 wt.%, more preferably in the range of 85.0-97.2 wt.% and most preferably in the range of 88.0-95.0 wt.%.

[0054] The aqueous bumetanide-containing preferably has a pH at 25°C in the range of 5.0-7.5, more preferably in the range of 5.5-7.0 and most preferably in the range of 5.8-6.5.

[0055] According to a preferred embodiment, the aqueous bumetanide-containing liquid contains a cation selected from sodium, potassium, lithium, ammonium, primary amine, secondary amine, tertiary amine, 2-hydroxyethyl(trimethyl)azanium (choline) and combinations thereof, said cation being present in a molar concentration that equals 50-150% of the molar concentration of bumetanide. More preferably, the cation is selected from sodium, potassium, lithium, ammonium, primary amine, secondary amine, 2-hydroxyethyl(trimethyl)azanium and combinations thereof. Examples of primary amines that may be employed include 2-amino-2- (hydroxymethyl)propaan-1 ,3-diol (tromethamine), 3-amino-1 -propanol and 2-amino-1 -ethanol (ethanolamine). Preferably, the primary amine employed is selected from 2-amino-2- (hydroxymethyl)propaan-1 ,3-diol (tromethamine), 3-amino-1 -propanol and combinations thereof. Triethanolamine is an example of a tertiary amine that may be employed.

[0056] According to a particularly preferred embodiment the aqueous bumetanide-containing liquid contains a cation selected from 2-hydroxyethyl(trimethyl)azanium, 2-amino-2- (hydroxymethyl)propaan-1 ,3-diol and combinations thereof in a molar concentration that exceeds 50%, more preferably exceeds 80% of the molar concentration of bumetanide.

[0057] According to a preferred embodiment the aqueous bumetanide-containing liquid contains 2- hydroxyethyl(trimethyl)azanium in a molar concentration that exceeds 50%, more preferably exceeds 80% of the molar concentration of bumetanide. More preferably, the liquid contains 2-hydroxyethyl(trimethyl)azanium in a molar concentration that exceeds 50%, more preferably exceeds 80% of the molar concentration of bumetanide.

[0058] The aqueous bumetanide-containing liquid preferably comprises a buffer having a buffering pH in the range of 6 to 8. The buffer is preferably selected from ammonium phosphate buffer, ammonium acetate buffer and ammonium citrate buffer.

[0059] In a preferred embodiment, the aqueous bumetanide-containing liquid contains 1-30 wt.%, more preferably 3-15 wt.% and most preferably 4-12 wt.% of non-ionic surfactant. The presence of nonionic surfactant was found to enhance the solubility of bumetanide at lower pH, e.g. at a pH below 7.0.

[0060] In a preferred embodiment, the non-ionic surfactant contained in the aqueous bumetanide- containing liquid of the present invention has a H LB of at least 10, more preferably of at least 12, most preferably of at least 14. The term HLB is an abbreviation of “hydrophile-lipophile balance”. The hydrophilic-lipophilic balance of a surfactant is a measure of the degree to which it is hydrophilic or lipophilic. The HLB as referred to in here is determined as described by J.T. Davies (A quantitative kinetic theory of emulsion type. I. physical chemistry of the emulsifying agent, Gas / Liquid and Liquid / liquid interfaces, Proceedings of 2ndInternational Congress Surface Activity, Butterworths, London 1957).

[0061] The HLB of the ionic surfactant preferably does not exceed 24, more preferably it does not exceed 22, most preferably it does not exceed 20. Preferably the non-ionic surfactant is selected from polyoxyethylene sorbitan esters of fatty acids, glycerol polyethylene glycol hydroxyl-fatty acid, polyethyleneglycol esters of fatty acids, poloxamers and mixtures thereof. More preferably, the non-ionic surfactant is selected from polyoxyethylene sorbitan esters of fatty acids. Most preferably, the non-ionic surfactant is polyoxyethylene (20) sorbitan monooleate.

[0062] Commercially available examples of suitable non-ionic surfactants according to the invention include Cremophor RH 40, Cremophor EL, Tween 20, Tween 80 and Pluronic F127.

[0063] In a further preferred embodiment, the aqueous liquid comprises at least 1wt.%, more preferably at least 5wt.%, most preferably at least 10 wt.% polyoxyethylene (20) sorbitan monooleate.

[0064] The aqueous bumetanide-containing liquid of the present invention may suitably contain a cosolvent. Examples of co-solvents that may be employed include ethanol, isopropyl alcohol, glycerol, propylene glycol, polyethylene glycol, glycofurol and combinations thereof.

[0065] Preferably, the non-ionic surfactant is fully dissolved in the aqueous liquid.

[0066] According to another preferred embodiment, the aqueous bumetanide-containing liquid contains 0.5-10 wt.%, more preferably 1-5 wt.% and most preferably 2-4 wt.% of nicotinamide. Nicotinamide was found to enhance the solubility of bumetanide at lower pH, e.g. at a pH below 7.0.

[0067] According to a preferred embodiment, the aqueous bumetanide-containing liquid does not comprise cationic and / or anionic surfactants.

[0068] Preferably the aqueous bumetanide-containing liquid is a clear liquid. If the liquid is clear, it is evident that no microbial growth or precipitation of bumetanide has occurred.

[0069] Preferably the aqueous bumetanide-containing liquid has an osmotic value of 100-800 mOsmol, more preferably 200-600 mOsmol and most preferably 300-400 mOsmol.

[0070] In a preferred embodiment, the aqueous bumetanide-containing liquid has a viscosity at 20°C and a shear rate of 16 s-1of not more than 200 mPa.s, preferably less than 100 mPa.s, more preferably 2-60 mPa.s measured with a Brookfield viscometer model RVDVII+ and using spindle 3. The viscosity of the aqueous bumetanide-containing liquid may be increased by adding a suitable thickening agent. Examples of thickening agents that may suitably be applied include alginic acid, alginate, HPMC, pectin, microcrystalline cellulose, carboxymethyl cellulose, carbomer, gellan, carrageenan, xanthan gum, agar, vegetable gums and combinations thereof. Typically, thickening agent is incorporated in a concentration of 0.1-5 wt.%, more preferably in a concentration of 0.15-3 wt.%.

[0071] The aqueous bumetanide-containing liquid of the invention preferably is a sterile composition. Sterilization may be achieved by methods known in the art, such as heat sterilization, high pressure sterilization and filtration sterilization.

[0072] The aqueous bumetanide-containing liquid may further comprise an effective amount of a preservative. Suitable preservatives are, for instance, phenoxy ethanol, benzalkonium chloride and benzyl alcohol, EDTA, potassium sorbate, sorbic acid, parahydroxybenzoate and combinations thereof.

[0073] The aqueous bumetanide-containing liquid may comprise antioxidants. Suitable antioxidants are for example ascorbic acid, carotenoids, vitamin A and tocopherol.

[0074] Yet another aspect of the invention relates to a spraying device comprising

[0075] • a container holding the aqueous bumetanide-containing liquid as defined herein before,

[0076] • a nozzle in fluid connection with the container, and

[0077] • a metered dose pump configured to create a flow of the aqueous bumetanide-containing liquid through the nozzle upon activation.

[0078] A specific type of spraying device has a microfilter in the air inlet, so the bottle cannot be contaminated in-use by incoming air. Another specific type of spraying device has no incoming air inlet and also has a spraying nozzle that is hermetically sealed at the end of each spray so no air can enter the device. This enables the oxygen free operation of the device. In case the product is prepared oxygen free, it will stay oxygen free during its entire use.

[0079] The spraying device of the present invention is preferably configured to deliver one spray dose upon nozzle activation. The activation of said nozzle is preferably a manual activation. Said spray dose preferably has a volume of 30 to 300 pl, more preferably of 50 to 250 pl. Another aspect of the invention relates to the use of the aqueous bumetanide-containing liquid as defined herein before in medical treatment, said treatment preferably comprising transmucosal administration of the liquid.

[0080] Examples of transmucosal administration include intranasal, intra-oral, intra-ocular and pulmonary administration. In a particularly preferred embodiment of the aforementioned treatment the aqueous bumetanide-containing liquid is administered intranasally.

[0081] More preferably, said the aqueous bumetanide-containing liquid is used in the prevention or treatment of edema, hyperkalemia, epileptic seizures, autism, hypertension, renal insufficiency, nephrotic syndrome, liver cirrhosis and / or heart failure, wherein the liquid is administered transmucosally.

[0082] In a preferred embodiment the aqueous bumetanide-containing liquid is administered transmucosally to deliver bumetanide in a dose of 0.2 to 3 mg , more preferably in a dose of 0.3 to 2.5 mg, most preferably in a dose of 0.5-2 mg.

[0083] Preferably, the intramucosal administration comprises 1-4 spray doses, said spray doses preferably having a volume of 30-100 pl.

[0084] Preferably the aqueous bumetanide-containing liquid is used in the treatment of a human.

[0085] The invention is further illustrated by the following non-limiting examples.

[0086] EXAMPLES

[0087] Example 1

[0088] An aqueous bumetanide-containing liquid according to the invention was prepared on the basis of the recipe shown in Table 1 :

[0089] Table 1

[0090] 120 cP, ex Chitinor, Norway The formulation was prepared as follows:

[0091] • Bumetanide was added to 75% of the water phase in a glass beaker.

[0092] • Next, the choline hydroxide was added to the water phase.

[0093] • The bumetanide was dissolved under stirring using a magnetic stirring rod.

[0094] • Under pH monitoring acetic acid was added until a pH of 6.5 is reached.

[0095] • Next, the Chitosan HCI was added.

[0096] • When the chitosan was fully dispersed the pH was again adjusted to 6.5 using acetic acid / choline hydroxide.

[0097] • Finally aqua purificata was added to complete to 100%.

[0098] The formulation was intranasally administered to human volunteers using a spraying device to deliver two doses of each approximately 100 pl (in total 0.5 mg bumetanide). The formulation could easily be administered and did not cause any irritation.

[0099] Example 2

[0100] An aqueous bumetanide-containing liquid according to the invention was prepared on the basis of the recipe shown in Table 2:

[0101] Table 2

[0102] The formulation was prepared in the same manner as in Example 1 , except that at the beginning of the procedure both the bumetanide and the nicotinamide were added to the water.

[0103] Example 3

[0104] The intranasal formulation of Example 2 was intranasally administered by means of a spraying device that delivered two doses of approximately 100 pl (in total 1 mg bumetanide).

[0105] The diuretic effect of the intranasally administered formulation was compared with the diuretic effect of a 1 mg bumetanide tablet (Burinex) and an intravenous dose (per injection) of 1 mg bumetanide (Burinex). All were done in fasted state. Since the diuretic effect was tested in a healthy volunteer (without edema), loss of urine was compensated for by drinking the same amount of aqueous beverage.

[0106] Additionally, bumetanide plasma levels following intranasal, oral and intravenous administration were measured at regular intervals.

[0107] The results of these analyses are summarized in Tables 3, 4 and 5.

[0108] Table 3

[0109] Table 4

[0110] Table 5 These results show that the intranasally administered bumetanide-containing liquid achieved a more rapid increase in bumetanide plasma concentrations and a faster diuretic effect than orally administered bumetanide. Furthermore bioavailability of the intranasally administered bumetanide was similar to that of orally administered bumetanide.

[0111] Comparative Example A

[0112] An aqueous bumetanide-containing liquid was prepared on the basis of the recipe that is shown in Table 2 of Example 2, except that chitosan HCI was replaced by water.

[0113] This formulation was intranasally administered by means of a spraying device that delivered two doses of approximately 100 pl (in total 1 mg bumetanide).

[0114] Diuretic effect and bumetanide plasma levels of the intranasally administered formulation were compared with those of a 1 mg bumetanide tablet (Burinex) and an intravenous dose (per injection) of 1 mg bumetanide (Burinex). The results are shown in Table 6.

[0115] Table 6

[0116] These results show that the bulk of the intranasally administered formulation had entered the gastro-intestinal tract by mucociliary clearance of the nostrils, followed by intestinal absorption of the bumetanide.

[0117] Example 4

[0118] Aqueous bumetanide-containing liquids according to the invention were prepared on the basis of the recipes shown in Table 7:

[0119] Table 7

[0120] The formulations were prepared as follows:

[0121] • Bumetanide and polysorbate 80 were added to 75% of the water phase in a glass beaker.

[0122] • Next, the base was added to the water phase.

[0123] • The bumetanide was dissolved under stirring using a magnetic stirring rod.

[0124] • Under pH monitoring acetic acid was added until the desired pH is reached.

[0125] • Next, the Chitosan HCI was added.

[0126] • When the chitosan was fully dispersed the pH was again adjusted to the desired pH using acetic acid / base.

[0127] • Finally aqua purificata was added to complete to 100%.

[0128] The formulations were stored at 5°C for 7 days. No precipitation was observed during this period.

[0129] The formulations were intranasally administered to human volunteers using a spraying device that delivered a dose of approximately 50 pl. With all formulations a total dosage of 1 mg bumetanide was delivered. The formulations could easily be administered and did not cause any irritation.

[0130] Bumetanide plasma levels of the intranasally administered formulations were determined. Several of the tested formulations showed a plasma concentration peaks at 45 and 110 minutes. The plasma concentration peak at 45 minutes is associated with intranasally absorbed bumetanide. The plasma concentration peak at 110 minutes is associated with intestinally absorbed bumetanide.

[0131] For each of the tested formulations the ratio of the bumetanide plasma concentration at 45 minutes and at 110 minutes was calculated. The results are shown in Table 8.

[0132] Table 8 Example 5

[0133] Aqueous bumetanide-containing liquids according to the invention are prepared on the basis of the recipes shown in Table 9:

[0134] Table 9

[0135] 1Ex Avantor / VWR

[0136] 2Ex Posanova GmbH, Germany

[0137] 3Ex Sigma-Aldrich

[0138] The formulations are prepared as follows:

[0139] • Bumetanide and polysorbate 80 are added to 75% of the water phase in a glass beaker.

[0140] • Next, the choline hydroxide is added to the water phase.

[0141] • The bumetanide is dissolved under stirring using a magnetic stirring rod.

[0142] • Under pH monitoring acetic acid is added until a pH of 6.5 is reached.

[0143] • Next, the amine-functional polymer is added.

[0144] • When the amine-functional polymer is fully dispersed the pH is again adjusted to 6.5using acetic acid / choline hydroxide.

[0145] • Finally aqua purificata was added to complete to 100%.

[0146] The formulations are stored at 4°C for 7 days. No precipitation is observed during this period.

[0147] The formulations are intranasally administered to human volunteers using a spraying device that delivers 100 doses of approximately 50 pl. The formulations can easily be administered and do not cause any irritation. For each of the tested formulations the ratio of the bumetanide plasma concentration at 45 minutes and at 110 minutes was determined. The results are shown in Table 10.

[0148] Table 10

[0149] Example 6

[0150] An aqueous bumetanide-containing liquid according to the invention was prepared on the basis of the recipe shown in Table 11:

[0151] Table 11

[0152] The formulations are prepared as follows:

[0153] • Bumetanide, polysorbate and nicotinamide were added to 75% of the water phase in a glass beaker.

[0154] • Next, the choline hydroxide was added to the water phase.

[0155] • The bumetanide was dissolved under stirring using a magnetic stirring rod.

[0156] • Under pH monitoring acetic acid was added until the desired pH is reached.

[0157] • Next, the Chitosan HCI was added.

[0158] • When the chitosan was fully dispersed the pH was again adjusted to the desired pH using acetic acid / choline hydroxide

[0159] • Finally aqua purificata was added to complete to 100%.

[0160] The formulation is intranasally administered to human volunteers using a spraying device that delivers a dose of approximately 50 pl. The formulation can easily be administered and does not cause any irritation. Excellent intranasal uptake of bumetanide is achieved. Example 7

[0161] An aqueous bumetanide-containing liquid according to the invention was prepared on the basis of the recipe shown in Table 12:

[0162] Table 12

[0163] The formulation was prepared by adding bumetanide, triethanolamine and 90% of the water. After dissolution the polysorbate and the butyl-4-hydroxybenzoate wee added. Next the pH was set to 6.5 using acetic acid, followed by addition of chitosan HCI. When the chitosan has been dissolved, pH is set to 6.5 using triethanolamine and HCI if needed.

[0164] Example 8

[0165] The intranasal formulation of Example 7 was intranasally administered by means of a spraying device that delivered one dose of approximately 50 pl (in total 1 mg bumetanide).

[0166] The diuretic effect of the intranasally administered formulation was compared with the diuretic effect of a 1 mg bumetanide tablet (Burinex®) and an intravenous dose (per injection) of 1 mg bumetanide (Burinex®). All were done in fasted state. Since the diuretic effect was tested in a healthy volunteer (without edema), loss of urine was compensated for by drinking the same amount of aqueous beverage.

[0167] Additionally, bumetanide plasma levels following intranasal, oral and intravenous administration were measured at regular intervals.

[0168] The results of these analyses are summarized in Tables 13 and 14.

[0169] Table 13

[0170] Table 14

Claims

CLAIMS1. An aqueous bumetanide-containing liquid comprising:• 0.1-5 wt.% bumetanide;• 0.1-10 wt.% of amine-functional polymer;• 65-99 wt.% water; wherein the aqueous bumetanide-containing liquid has a pH at 25°C in the range of 5 to 8.

2. The aqueous bumetanide-containing liquid according to claim 1 , wherein the liquid comprises 0.25-4 wt.%, preferably 0.35-3 wt.% more preferably, 0.5-2.0 wt.% of bumetanide.

3. The aqueous bumetanide-containing liquid according to claim 1 or 2, wherein the bumetanide is fully dissolved in the aqueous liquid.

4. The aqueous bumetanide-containing liquid according to any one of the preceding claims, wherein the liquid comprises 0.15-4 wt.%, preferably 0.18-2 wt.%, more preferably 0.20-1 wt.% of the amine-functional polymer.

5. The aqueous bumetanide-containing liquid according to any one of the preceding claims, wherein the amine-functional polymer is selected from chitosan, quaternised chitosan, carboxymethyl chitosan, amino-functionalised dextran, amino-functionalised cellulose, aminofunctionalised polyoxazoline, amino-functionalised cyclodextrin, protamine, gelatine, poly- L(lysine), poly(ethyleneimine), poly(amidoamine), poly(amino-co-ester), poly[2-(N,N- dimethylamino)ethyl methacrylate] and combinations thereof.

6. The aqueous bumetanide-containing liquid according to any one of the preceding claims, wherein bumetanide and the amine-functional polymer are present in a weight ratio of 0.4 to 8.

7. The aqueous bumetanide-containing liquid according to any one of the preceding claims, wherein the amine-functional polymer has a cationic charge density of at least 1 meq / g at the pH of the liquid at 25°C.

8. The aqueous bumetanide-containing liquid according to any one of the preceding claims, wherein the liquid has a pH at 25°C in the range of 5.5-7.5, preferably in the range of 5.8-7.2.

9. The aqueous bumetanide-containing liquid according to any one of the preceding claims, wherein the liquid contains cation selected from sodium, potassium, lithium, ammonium, primary amine, secondary amine 2-hydroxyethyl(trimethyl)azanium and combinations thereof, said cation being present in a molar concentration that equals 50-150% of the molar concentration of bumetanide.

10. The aqueous bumetanide-containing liquid according to any one of the preceding claims, wherein the aqueous bumetanide-containing liquid contains 1-30 wt.% of non-ionic surfactant.11 . The aqueous bumetanide-containing liquid according to any one of the preceding claims, wherein the liquid is a clear liquid.

12. A spraying device comprising• a container holding the aqueous bumetanide-containing liquid as defined in any one of claims 1-10,• a nozzle in fluid connection with the container, and• a metered dose pump configured to create a flow of the aqueous bumetanide-containing liquid through the nozzle upon activation.

13. An aqueous bumetanide-containing liquid as defined in any one of claims 1-11 for use in medical treatment, said treatment comprising transmucosal administration of the aqueous bumetanide-containing liquid.

14. The aqueous bumetanide-containing liquid for use according to claim 13, wherein the liquid is administered intranasally.

15. The aqueous bumetanide-containing liquid for use according to claim 13 or 14, wherein the liquid is administered to deliver bumetanide in a dose of 0.5 to 5 mg.

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