FIELD

The invention relates to compositions comprising solubilised and bioavailable niclosamide, methods for their administration and use in treatment.

BACKGROUND

Halogenated salicylanilides are a class of compounds comprising a core 2-hydroxy- N-phenylbenzamide moiety substituted on the aromatic rings with one or more halogens, and may comprise other additional substituents. The class of halogenated salicylanilides includes niclosamide, oxyclozanide, rafoxanide and closantel.

Niclosamide is approved as an anthelminthic drug and it has been widely used in humans to treat tapeworm infections. It is currently listed on the World Health Organization's list of essential medicines. Oxyclozanide, rafoxanide and closantel similarly have anthelminthic properties, and are used in the treatment of parasites, such as Fasciola and Haemonchus in domestic animals such as sheep and cattle.

Whilst the class of halogenated salicylanilides are most commonly used for the treatment of parasitic infections, the compounds have potential application in a variety of pharmacological applications, and have the potential to provide a therapeutic effect via several mechanisms of action.

Studies indicate that the mechanism of action of niclosamide in the treatment of parasitic (tapeworm) infections is by the inhibition of oxidative phosphorylation and stimulation of adenosine triphosphatase activity. Niclosamide has more recently been reported to act on Wnt/0-catenin, mTOR and JAK/STAT3 signalling pathways, and as a result it is believed to have potential to treat conditions such as cancer, bacterial and viral infections, and metabolic diseases.

Methods of administering halogenated salicylanilides are generally via oral administration. Halogenated salicylanilide compounds have low solubility in water and in oil, which substantially limits the absorption of these compounds through the gut lumen. Niclosamide has been regarded since 1982 by the United States Food and Drug Administration as a safe drug to be administered orally.

Poor absorption of known halogenated salicylanilide formulations via the oral route presents a barrier for halogenated salicylanilides being bioavailable for the treatment of diseases and conditions beyond those directly affecting the gut.

Accordingly, there is a need to provide compositions comprising niclosamide in which the niclosamide is systemically bioavailable. There is also a need to provide compositions comprising niclosamide in a form suitable for treating diseases or conditions that are not confined to the gut.

SUMMARY OF THE INVENTION

The inventions described and claimed herein have many attributes and embodiments including, but not limited to, those set forth or described or referenced in this Summary of the Invention. It is not intended to be all-inclusive and the inventions described and claimed herein are not limited to or by the features or examples identified in this Summary of the Invention, which is included for purposes of illustration only and not restriction.

In an aspect, there is provided a composition comprising a) niclosamide or a pharmaceutically acceptable salt, hydrate, solvate, or ester thereof; and b) one or both of a polysorbate and a polyethylene glycol; wherein the niclosamide is solubilised in the composition.

The composition may be a liquid composition, a solid composition or a semisolid composition at room temperature. Preferably, the composition is a liquid composition at body temperature (e.g. between about 36 and 40 °C).

The composition may comprise at least 10% by weight polysorbate, or at least 20% by weight polysorbate, or at least 30% by weight polysorbate, or at least 40% by weight polysorbate, or at least 50% by weight polysorbate, or at least 60% by weight polysorbate, or at least 70% by weight polysorbate, or at least 80% by weight polysorbate, or at least 85% by weight polysorbate, or at least 90% by weight polysorbate, or at least 95% by weight polysorbate.

The composition may comprise at least 10% by weight polyethylene glycol, or at least 20% by weight polyethylene glycol, or at least 30% by weight polyethylene glycol, or at least 40% by weight polyethylene glycol, or at least 50% by weight polyethylene glycol, or at least 60% by weight polyethylene glycol, or at least 70% by weight polyethylene glycol, or at least 80% by weight polyethylene glycol, or at least 85% by weight polyethylene glycol, or at least 90% by weight polyethylene glycol, or at least 95% by weight polyethylene glycol.

Preferably, the ratio of polysorbate to polyethylene glycol in the composition is between 1:99 and 99: 1, or between 5:95 and 95:5, or between 10:90 and 90: 10, or between 20:80 and 80:20, or between 30:70 and 70:30, or between 40:60 and 60:40, or between 45:55 and 55:45, or about 50:50, by weight. Preferably, the composition comprises at least 90% by weight of the one or both of the polysorbate and polyethylene glycol.

The composition may comprise at least 0.01% by weight of niclosamide, for example between 0.01% w/v to 10% w/v, between 0.01% to 8% w/v, between 0.01% to 7% w/v, between 0.01% to 6% w/v, between 0.01% to 5.5% w/v, between 0.01% to 5% w/v, about 1% w/v, about 2% w/v, about 3% w/v, about 4% w/v, about 5% w/v, about 6% w/v, or about 7% w/v.

In some embodiments, niclosamide may be present in an amount that exceeds its solubility in the one or both of the polysorbate and polyethylene glycol. The composition preferably comprises up to 7% by weight solubilised niclosamide, or between 1% and 7% by weight solubilised niclosamide.

Preferably, the polyethylene glycol has an average molecular weight of between 200 and 4000.

The niclosamide is preferably solubilised in the one or both of the polysorbate and the polyethylene glycol.

The polysorbate may be selected from the group comprising polysorbate 20, polysorbate 40, polysorbate 60, polysorbate 80, polysorbate 85, and a combination thereof.

In another aspect, there is provided a composition consisting essentially of niclosamide or a pharmaceutically acceptable salt, hydrate, solvate, or ester thereof and a polysorbate.

In another aspect, there is provided a composition consisting essentially of niclosamide or a pharmaceutically acceptable salt, hydrate, solvate, or ester thereof, a polysorbate, and a polyethylene glycol.

In another aspect, there is provided a method for increasing the amount of niclosamide in the blood or tissues of an animal comprising the administration to the animal of the composition.

The animal may be selected from a human or a non-human animal, for example a mammal, domestic livestock (including cow, sheep, goat, pig), poultry (including chicken, duck, goose), guinea pig, ferret, primate, dog, cat, rabbit, mouse, or rat.

The route of administration may comprise oral administration, intranasal administration, inhalation administration, parenteral administration, intramuscular administration, subcutaneous administration, intraperitoneal administration, intravenous administration, intramammary administration, buccal administration, or rectal administration.

In another aspect, there is provided a method for treating or preventing a parasitic infection, a bacterial infection, a viral infection, the growth or proliferation of cancerous cells, Parkinson's disease, Type 2 diabetes, non-alcoholic fatty liver disease, artery constriction, endometriosis, neuropathic pain, rheumatoid arthritis, sclerodermatous graft - versus-host disease, or systemic sclerosis, comprising the administration of the composition.

In another aspect, there is provided a use of the composition in the manufacture of a medicament for increasing the amount of niclosamide in the blood or tissues of an animal.

In another aspect, there is provided a use of the composition in the manufacture of a medicament for treating or preventing a parasitic infection, a bacterial infection, a viral infection, the growth or proliferation of cancerous cells, Parkinson's disease, Type 2 diabetes, non-alcoholic fatty liver disease, artery constriction, endometriosis, neuropathic pain, rheumatoid arthritis, sclerodermatous graft-versus-host disease, or systemic sclerosis.

In another aspect, there is provided a composition for rectal administration comprising a) niclosamide or a pharmaceutically acceptable salt, hydrate, solvate, or ester thereof; and b) polyethylene glycol.

The composition may be in the form of a suppository.

The composition may comprise at least 1% by weight niclosamide.

The composition may comprise between 1% and 50% by weight niclosamide, for example, between 10% and 50% by weight niclosamide.

The polyethylene glycol may have an average molecular weight of at least 1,400, for example, an average molecular weight of between 1,400 and 4,000.

The composition may comprise at least 10% by weight polyethylene glycol, or at least 20% by weight polyethylene glycol, or at least 30% by weight polyethylene glycol, or at least 40% by weight polyethylene glycol, or at least 50% by weight polyethylene glycol, or at least 60% by weight polyethylene glycol, or at least 70% by weight polyethylene glycol, or at least 80% by weight polyethylene glycol, or at least 85% by weight polyethylene glycol, or at least 90% by weight polyethylene glycol, or at least 95% by weight polyethylene glycol.

The composition may further comprise polysorbate. The polysorbate may comprise polysorbate 20, polysorbate 40, polysorbate 60, polysorbate 80, and/or polysorbate 85.

The composition may comprise at least 10% by weight polysorbate, or at least 20% by weight polysorbate, or at least 30% by weight polysorbate, or at least 40% by weight polysorbate, or at least 50% by weight polysorbate, or at least 60% by weight polysorbate, or at least 70% by weight polysorbate, or at least 80% by weight polysorbate, or at least 85% by weight polysorbate, or at least 90% by weight polysorbate, or at least 95% by weight polysorbate.

The niclosamide may be solubilised in the composition.

In another aspect, there is provided a suppository composition consisting essentially of niclosamide or a pharmaceutically acceptable salt, hydrate, solvate, or ester thereof and a polyethylene glycol.

In another aspect, there is provided a suppository composition consisting essentially of niclosamide or a pharmaceutically acceptable salt, hydrate, solvate, or ester thereof , a polysorbate, and a polyethylene glycol.

BRIEF DESCRIPTION OF THE FIGURES

Figures la and lb shows the blood plasma concentrations of niclosamide (ng niclosamide per mL plasma) during the trial described in Example 4.

Figure 2 shows the blood plasma concentrations of niclosamide (ng niclosamide per mL plasma) during the trial described in Example 6.

Figure 3 shows the blood plasma concentrations of niclosamide (ng niclosamide per mL plasma) during the trial described in Example 7.

Figure 4 shows zones of inhibition testing against strains of Staphylococcus caused by the composition described in Example 8.

DEFINITIONS

Unless specifically defined otherwise, all technical and scientific terms used herein shall be taken to have the same meaning as commonly understood by one of ordinary skill in the art.

It is intended that reference to a range of numbers disclosed herein (e.g. 1 to 10) also incorporates reference to all related numbers within that range (e.g. 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9 and 10) and also any range of rational numbers within that range (for example 2 to 8, 1.5 to 5.5 and 3.1 to 4.7) and, therefore, all sub-ranges of all ranges expressly disclosed herein are expressly disclosed. These are only examples of what is specifically intended and all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be expressly stated in this application in a similar manner.

The term "and/or", e.g., "X and/or Y" shall be understood to mean either "X and Y" or "X or Y" and shall be taken to provide explicit support for both meanings or for either meaning.

Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer, or step, or group of elements, integers, or steps, but not the exclusion of any other element, integer, or step, or group of elements, integers, or steps.

Throughout this specification, unless specifically stated otherwise or the context requires otherwise, reference to a single step, composition of matter, group of steps, or group of compositions of matter shall be taken to encompass one and a plurality (i.e. one or more) of those steps, compositions of matter, groups of steps, or group of compositions of matter.

"Pharmaceutically acceptable" in relation to salts, hydrates, solvates, and esters, means salts, hydrates, solvates, and esters, that retain the biological effectiveness and properties of the compounds described herein and, which are not biologically or otherwise undesirable. Pharmaceutically acceptable salts, hydrates, solvates, and esters are well known to skilled persons in the art.

"Halogenated salicylanilide" comprises any of the halogenated salicylanilides disclosed herein including closantel, rafoxanide, oxyclozanide, niclosamide, and derivatives thereof including salts, hydrates, solvates, and esters thereof.

"Polysorbate" means a surfactant comprised of fatty acid esters of polyoxyethylene sorbitan. The fatty acid composition may be selected from lauric acid, palmitic acid, stearic acid, and oleic acid. "Polysorbate 80" is a polysorbate in which oleic acid predominates as the fatty acid moiety. "Polysorbate 60" is a polysorbate in which stearic acid predominates as the fatty acid moiety. "Polysorbate 40" is a polysorbate in which palmitic acid predominates as the fatty acid moiety. "Polysorbate 20" is a polysorbate in which lauric acid predominates as the fatty acid moiety.

DETAILED DESCRIPTION It has surprisingly been found that compositions comprising solubilised niclosamide may be prepared that are suitable for administration to an animal or human

It has surprisingly been found that compositions comprising niclosamide, solubilised in one or both of polysorbate and polyethylene glycol are suitable for administration to an animal and human and provide good systemic bioavailability of the niclosamide when administered via a number of different routes of administration.

The compositions of the present invention therefore comprise a niclosamide, or a pharmaceutically acceptable salt, hydrate, solvate, or ester thereof; and one or both of a polysorbate and a polyethylene glycol; wherein the niclosamide is solubilised in the composition.

The inventors have surprisingly found that polysorbate and polyethylene glycol are suitable carriers for a solubilised niclosamide composition. Example 1 shows that niclosamide has a low solubility in a selection of pharmaceutically acceptable carriers, but was observed to have higher solubility in polysorbates, polyethylene glycols and combinations thereof. Example 2 shows more specifically the solubility of niclosamide in polysorbate 80 and/or polyethylene glycol 400 at concentrations of 1% w/v and 5% w/v. The compositions were optionally filtered prior to analysis to ensure that the niclosamide present in the compositions was solubilised niclosamide.

Halogenated salicylanilide

Whilst niclosamide is a preferred halogenated salicylanilide for the compositions of the invention, other halogenated salicylanilides are envisaged as within the scope of this invention. In addition to niclosamide, examples of other halogenated salicylanilides include oxyclozanide, rafoxanide, and closantel. The compositions may include combinations of one or more halogenated salicylanilides.

Any pharmaceutically acceptable form of halogenated salicylanilide is suitable for the composition of the invention. The skilled person will readily understand that halogenated salicylanilides, as a class, may be provided in freebase, salt, hydrate, or solvate form. In an example, the halogenated salicylanilide may be provided as a prodrug, such as an ester of a halogenated salicylanilide, e.g. a halogenated salicylanilide esterified at the 2-hydroxy on the benzamide moiety.

For example, niclosamide may be provided as its freebase form, a salt, a crystalline or amorphous solid, a hydrate, a solvate, or as a prodrug such as an ester of niclosamide. In compositions of the invention where the halogenated salicylanilide is niclosamide, the niclosamide may be provided as niclosamide, niclosamide monohydrate, niclosamide dihydrate, niclosamide trihydrate, niclosamide ethanolamine salt, niclosamide piperazine salt, or esters thereof.

The concentration of niclosamide may have an upper limit determined by its maximum solubility in the composition. Preferred compositions comprise the niclosamide in amounts of 0.01% w/v to 10% w/v, for example from 0.01% to 8% w/v, from 0.01% to 7% w/v, from 0.01% to 6% w/v, from 0.01% to 5.5% w/v, from 0.01% to 5% w/v, for example about 1% w/v, about 2% w/v, about 3% w/v, about 4% w/v, about 5% w/v, about 6% w/v, or about 7% w/v.

In embodiments where the composition comprises niclosamide and one or both of polysorbate 80 and a polyethylene glycol 400, a particularly preferred upper limit to niclosamide concentration solubilised in the composition is 7% w/v. This is because niclosamide has been found to have a maximum solubility in these carriers of 7%.

The compositions may further comprise one or more additional active pharmaceutical agents.

Carrier

In addition to niclosamide, the composition comprises a polysorbate, a polyethylene glycol, or a combination thereof. The composition preferably comprises at least 90% by weight of the one or both of the polysorbate and polyethylene glycol.

Polysorbate

Polysorbate 80 is preferred for the present invention, as it has been found to solubilise niclosamide in concentrations up to 6% w/v (see Example 1). Alternative polysorbates that may be used in the present invention include polysorbate 20, polysorbate 40, polysorbate 60, and polysorbate 85. Whilst niclosamide may have a lower solubility in the alternative polysorbates, these are nonetheless suitable for lower solubilised niclosamide concentrations. For example, polysorbate 20 solubilises niclosamide in amounts of about 1% by weight.

The compositions of the invention may comprise at least 10% by weight polysorbate, at least 20% by weight polysorbate, at least 30% by weight polysorbate, at least 40% by weight polysorbate, at least 50% by weight polysorbate, at least 60% by weight polysorbate, at least 70% by weight polysorbate, 80% by weight polysorbate, or at least 85% by weight polysorbate, or at least 90% by weight polysorbate, or at least 95% by weight polysorbate.

The inventors have found that niclosamide is fully soluble in polysorbate 80 in concentrations of up to 6% w/v. Whilst compositions of up to 6 % w/v niclosamide are demonstrated in the Examples, higher or lower concentrations of niclosamide are also envisaged within the scope of the present invention. For example, compositions may be prepared comprising polysorbate as the carrier of a solubilised niclosamide composition with a niclosamide concentration of 0.01% w/v up to 10% w/v.

The compositions of the invention may consist of, or consist essentially of, niclosamide and a polysorbate.

Polyethylene glycol

In some embodiments, the composition may comprise carriers other than polysorbate. Polyethylene glycol has been found to solubilise niclosamide and is another preferred carrier. Polyethylene glycol 400 is shown herein to solubilise niclosamide in concentrations up to 7% w/v, and is accordingly a particularly preferred carrier.

The compositions of the invention may comprise at least 10% by weight polyethylene glycol, at least 20% by weight polyethylene glycol, at least 30% by weight polyethylene glycol, at least 40% by weight polyethylene glycol, at least 50% by weight polyethylene glycol, at least 60% by weight polyethylene glycol, at least 70% by weight polyethylene glycol, 80% by weight polyethylene glycol, or at least 85% by weight polyethylene glycol, or at least 90% by weight polyethylene glycol, or at least 95% by weight polyethylene glycol.

For example, the composition may include a combination of polysorbate and an additional carrier. Suitable additional carriers are those that do not materially affect the solubility of niclosamide in solution with polysorbate at the concentrations used in the present invention, and are suitable for various routes of administration to animals. Examples of preferred routes of administration include oral administration, intranasal administration, inhalation administration, parenteral administration, intramuscular administration, subcutaneous administration, intraperitoneal administration, intravenous administration, intramammary administration, buccal administration, or rectal administration.

Where the composition is adapted for administration via a syringe (such as via intravenous, intraperitoneal, intramuscular, or subcutaneous routes of administration), preferred additional carriers are those that reduce the viscosity of the composition, whilst retaining the niclosamide in solution. An example of a suitable additional carrier is polyethylene glycol (PEG). Suitable PEG molecular weights include PEG 200, PEG 300, PEG 400, PEG 600. Preferred molecular weights of PEG are between 200 and 400 as these have a lower viscosity. The inventors have found that the addition of polyethylene glycol 400 to the polysorbate compositions reduces the viscosity of the composition and facilitates administration of the composition, for example via narrow gauge catheters, needles, or syringes, while at the same time maintaining the solubility of niclosamide in acceptable concentrations.

Example 1 shows that the solubility of niclosamide in a 1 : 1 (by weight) mixture of polysorbate 80 and polyethylene glycol 400 is 6% w/v. Other suitable additional carriers include polypropylene glycol. This shows that combinations of polysorbate and polyethylene glycol solubilise niclosamide at concentrations that would be expected based on the solubility of niclosamide in polysorbate and polyethylene glycol separately. Where the compositions of the present invention include polysorbate and polyethylene glycol, relative amounts of polysorbate and polyethylene glycol may be between about 0.01:99.99 to 99.99:0.01.

The compositions of the invention may consist of, or consist essentially of, niclosamide, a polysorbate, and a polyethylene glycol.

Route of administration

Preferred routes of administration include oral administration, intranasal administration, inhalation administration, parenteral administration, intramuscular administration, subcutaneous administration, intraperitoneal administration, intravenous administration, intramammary administration, buccal administration, or rectal administration.

In vivo tests disclosed herein indicate that oral, rectal, buccal and intraperitoneal routes of administration provide sufficient niclosamide in the blood to be therapeutically effective.

Example 4 shows that pigs administered a composition of solubilised niclosamide in polysorbate 80 via intraperitoneal administration exhibited a niclosamide blood plasma Cmax of 650 ng/ml (where the dose was 3.0 mg/kg niclosamide) and Cmax of 290 ng/ml (where the dose was 1.5 mg/kg). Where a niclosamide suspension in saline was identically administered, the Cmax levels observed were 44 and 37 ng/ml for dosages of 3.0 and 1.5 mg/kg, respectively. This shows that a solubilised niclosamide composition in polysorbate 80 provides much greater bioavailability compared to a suspension. Accordingly, the composition may be safely intraperitoneally administered at dosage rates up to 3 mg/kg niclosamide.

Based on, inter alia, the observations of intraperitoneal administration in the Examples herein, the skilled person would understand that the composition may be adapted for other routes of systemic administration (such as intravenous, intramuscular or subcutaneous administration) and achieve good bioavailability of niclosamide. Oral

It has been surprisingly found that the solubilised niclosamide compositions of the present invention may be orally administered and provide good bioavailability of niclosamide.

Examples 4, 6 and 7 show various dosage rates of 1.5, 3, 5, 9 and 15 mg/kg niclosamide to animals. In each case, niclosamide was observed in the blood plasma at significantly higher concentrations compared to aqueous niclosamide compositions. Accordingly, the composition may be orally administered at dosage rates up to 15 mg/kg niclosamide.

Example 4 shows the buccal administration of the solubilised niclosamide composition caused a niclosamide blood plasma Cmax of 41 and 43 ng/ml for dosages of 3.0 and 1.5 mg/kg, respectively. Example 6 shows that pigs administered the solubilised niclosamide composition (5 mg/kg niclosamide) caused a niclosamide blood plasma Cmax of about 55 ng/ml. Example 7 shows that pigs administered the solubilised composition of niclosamide via oral gavage caused a niclosamide blood plasma Cmax (mean) of 140 or 150 ng/ml for dosages of 9.0 or 15 mg/kg. Where a niclosamide suspension in saline was administered identically to the solubilised composition, the Cmax (mean) levels observed were 12 and 22 ng/ml for dosages of 9 and 15 mg/kg, respectively. This shows that niclosamide may be made orally bioavailable by solubilisation with polysorbate and polyethylene glycol, and that a solubilised niclosamide composition of the present invention is bioavailable whereas the niclosamide suspensions are significantly lower.

Intramammary

The composition may be administered to the teat of a mammal. In this embodiment, the composition is infused in the teat and massaged up the teat canal towards the mammary gland.

Intramammary administration of the compositions of the present invention may be used to apply niclosamide to the mammary gland of an animal to treat diseases or conditions affecting the teats, mammary glands or mammary tissue that are treatable by niclosamide. This route is a more direct way of infusing the composition into the mammary tissues.

Rectal

It has surprisingly been found that compositions comprising niclosamide are suitable for rectal administration to an animal. It has surprisingly been found that such compositions, administered rectally, provides systemic bioavailability of the niclosamide. There is therefore provided a composition comprising niclosamide adapted for rectal administration. Rectally administered compositions may include formulations adapted as, without limitation, rectal gels, rectal foams, rectal aerosols, suppositories, jelly suppositories, and enemas (e.g., retention enemas).

A preferred composition is a suppository formulation comprising niclosamide and a carrier suitable for a suppository formulation. Suitable carriers provide for a solid formulation at room temperature that may soften or melt at body temperature, in order to provide for ease of handling and administration, and good delivery of niclosamide once administered. Suitable carriers include polyethylene glycol, polysorbate, and combinations thereof.

The carrier may make up between 1% and 99.9 % w/w of the composition, for example, between 10% w/w and 99.9% w/w, or between 20% w/w and 99.9% w/w, or between 30% w/w and 99.9% w/w, or between 40% w/w and 99.9% w/w, or between 50% w/w and 99.9% w/w, or between 60% w/w and 99.9% w/w, or between 70% w/w and 99.9% w/w, or between 80% w/w and 99.9% w/w, or between 90% w/w and 99.9% w/w.

In an example, the carrier may comprise a polyethylene glycol. The polyethylene glycol may be polyethylene glycol with an average molecular weight of about 1,450 to about 4,000, or an average molecular weight of between 1,400 and 4,000 (achieved by, for example, a combination of polyethylene glycol 1450 and polyethylene glycol 4000).

In another example, the carrier may comprise a polysorbate, such as polysorbate 80, in combination with another carrier to provide a solid formulation at room temperature.

In another example, the carrier may comprise a combination of polysorbate and polyethylene glycol, such as a combination of polysorbate 80 and polyethylene glycol with an average molecular weight of about 1,450, or about 4,000, or an average molecular weight of between 1,400 and 4,000. Relative amounts of polysorbate and polyethylene glycol may be between about 0.01:99.99 to 20:80, and more preferably about 10:90.

Compositions of 10, 20, 30, 40 and 50 % w/w niclosamide are demonstrated in Example 5. Higher or lower concentrations of niclosamide are envisaged within the scope of the present invention. Preferred compositions comprise the niclosamide in amounts of 0.01% w/w to 99% w/w, for example from 0.01% to 80% w/w, from 0.01% to 70% w/w, from 0.01% to 60% w/w, from 0.01% to 55% w/w.

Method of administration

It has surprisingly been found that niclosamide compositions described herein may be administered to an animal via a number of different routes to achieve bioavailability. Systemic administration of the compositions to a subject has surprisingly been found to cause an increase in the amount of niclosamide in the bloodstream of the subject.

There is therefore provided a method for increasing the amount of a niclosamide in the blood and tissues of an animal comprising the systemic administration of a composition comprising niclosamide to the animal.

The animal may be a human or a non-human animal. Examples of non-human animals that may be administered the composition of the present invention include domestic livestock (including cow, sheep, goat, pig), poultry (including chicken, duck, goose), guinea pig, ferret, primate, dog, cat, rabbit, mouse, or rat. Preferably, the animal is a mammal.

Whilst intraperitoneal administration of the compositions of the invention is demonstrated in the Examples as an example of systemic administration, other routes of administration to achieve bioavailability include oral, intravenous administration, intramuscular administration, intramammary administration, rectal administration, and buccal administration.

Dosage

Dosages of the composition to an animal depend on the route of administration. The method of the invention may be performed with niclosamide dosages between 0.01 mg/kg and 20 mg/kg, or between 1.5 and 15 mg/kg, or between 3 and 15 mg/kg.

For oral administration, a suitable upper limit to the dosage is 20 mg/kg niclosamide.

For intraperitoneal administration, a preferred upper limit to the dosage is 5 mg/kg niclosamide.

Example 4 shows that niclosamide Cmax levels following intraperitoneal administration were 650 ng/ml for a dosage rate of 3 mg/kg. No adverse effects were observed in the subjects. Accordingly, in preferred embodiments, the composition may be administered to provide a Cmax of at least 10 ng/mL, at least 30 ng/mL, at least 40 ng/mL, at least 50 ng/mL, at least 100 ng/mL, at least 150 ng/mL, at least 200 ng/mL, at least 250 ng/mL, at least 300 ng/mL, at least 350 ng/mL, at least 400 ng/mL, at least 450 ng/mL, at least 500 ng/mL, at least 550 ng/mL, at least 600 ng/mL, at least 650 ng/mL, at least 700 ng/mL, at least 750 ng/mL, at least 800 ng/mL, at least 850 ng/mL, at least 900 ng/mL, at least 950 ng/mL, at least 1000 ng/mL.

Where the composition comprises a solubilised niclosamide and polysorbate, intraperitoneal administration of a dose of the composition at 1.5 mg/kg leads to a plasma Cmax of at least 100 ng/mL, at least 150 ng/mL, at least 200 ng/mL, at least 250 ng/mL, and intraperitoneal administration of a dose of 3 mg/kg leads to a plasma Cmax of at least at least 100 ng/mL, at least 150 ng/mL, at least 200 ng/mL, at least 250 ng/mL, at least 300 ng/mL, at least 350 ng/mL, at least 400 ng/mL, at least 450 ng/mL, at least 500 ng/mL, at least 550 ng/mL, at least 600 ng/mL, at least 650 ng/mL.

Whilst the Examples indicate that intraperitoneal administration of a composition of the invention provides a higher Cmax compared to oral, rectal and buccal routes of administration for the same dosage of halogenated salicylanilide (see the Examples), oral, rectal and buccal administration is less invasive and can be administered without the need for specialised training that is required for the intraperitoneal route. The amounts of niclosamide in plasma described in the Examples and shown in the Figures demonstrates that oral, rectal and buccal administration routes have the potential to provide a therapeutically effective amount of niclosamide to an animal in need thereof.

The surprising finding of an increase in niclosamide in blood plasma as a result of systemic administration of the compositions of the invention creates an opportunity an effective treatment of bacterial and/or viral infections, cancers, autoimmune and metabolic disorders.

Example 8 demonstrates the antimicrobial activity of solubilised compositions of 5 % by weight niclosamide. The zone of inhibition was carried out against strains of Staphylococcus, and displayed a zone of inhibition where the antimicrobial activity of the composition prevented the growth of the bacteria. This data shows that the compositions of the present invention have antimicrobial activity. As the Staphylococcus samples include those taken from bovine milk samples from cows suffering from mastitis, the compositions show potential in the treatment of mastitis, especially in the treatment of mastitis in dairy cows.

As many gut parasites have a phase whereby they migrate through tissue before returning to the gut, it is desirable to be able to systemically administer anthelminthics to treat gut parasites beyond the gut. Accordingly, the compositions of the invention may be used to treat parasitic infections, such as tapeworms and flukes. Other parasites include Trichinella spp, Toxoplasma spp, Eimeria (and Cystoisospora, and other coccidia), Toxoplasma spp, Sarcocystis spp, Taenia spp. The compositions of the invention may be used to treat viral infections, such as coronavirus infections, flavivirus infections, hepatitis C virus, Ebola virus, rhinovirus (e.g. human rhinovirus), chikungunya virus, adenovirus (e.g. human adenovirus), Epstein-Barr virus. The compositions of the invention may be used to treat bacterial infections, such as tuberculosis, anthrax, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus hyicus. The compositions of the invention may be used to treat cancers, such as adrenocortical carcinoma, breast cancer, colon cancer, glioma, head and neck cancer, leukaemia, lung cancer, osteosarcoma, ovarian cancer, prostate cancer, renal cell carcinoma. The compositions of the invention may be used to treat disorders, such as Parkinson's disease, Type 2 diabetes, non-alcoholic fatty liver disease, artery constriction, endometriosis, neuropathic pain, rheumatoid arthritis, sclerodermatous graft-versus-host disease, systemic sclerosis.

Example 1 - Solubility of niclosamide

The following procedure was adopted to determine the solubility of niclosamide in selected carriers:

Niclosamide (1 g) was added to 100 mL solvent in a flask with continuous agitation at room temperature. Niclosamide was added in further 1 g increments until there were visible signs of precipitate.

The above procedure was repeated with solvent temperature of 60°C. Soluble compositions were refrigerated for a week and checked for signs of crystallization. The solubility of niclosamide in selected carriers is shown in Table 1.

Table 1

Example 2 - Liquid compositions comprising niclosamide

Formulations comprising solubilised niclosamide in polysorbate, identified as Samples 1 and 3 in Table 2 below, were prepared according to the following general methodology: Niclosamide was combined with polysorbate 80 at 30 degrees C under aseptic conditions, and the resulting combinations were stirred until the mixtures appeared clear (about 1 hour). The resulting solutions (Sample 1: niclosamide 5% w/v in polysorbate 80; Sample 3: niclosamide 1% in polysorbate 80) were optionally filtered using a 0.22 pm filter and transferred into sterile vials under laminar flow. The resulting aseptic solutions were tested by spectrophotometer to quantify the amount of niclosamide and confirm the niclosamide concentration in each composition.

A formulation comprising solubilised niclosamide in polyethylene glycol, identified as Sample 2 in Table 2 below, was prepared according to the following general methodology: Niclosamide was combined with polyethylene glycol 400 at 30 degrees C under aseptic conditions. The resulting aseptic solution was tested by spectrophotometer to quantify the amount of niclosamide and confirm the niclosamide concentration in each composition.

A formulation comprising solubilised niclosamide in polysorbate and polyethylene glycol, identified as Sample 4 in Table 2 below, was prepared according to the following general methodology: 50 grams of polysorbate 80 were combined with 40 grams of polyethylene glycol 400, and gently heated to between 40 °C and 50 °C. 5 grams of niclosamide was added and then the mixture was stirred until the niclosamide was completely dissolved and the solution became clear. The mixture was cooled to below 30 °C, and then the volume of the mixture was increased to 100 ml by addition of polyethylene glycol 400. The mixture was then mixed for ten minutes. The mixture was optionally filtered.

Soluble niclosamide formulations were prepared with the compositions described in Table 2. Table 2

To determine whether dilution of the samples with aqueous carrier disrupted the solubility of niclosamide in the composition, 1 mL of each of Samples 2, 3 and 4 were added to 250 ml of 5% aqueous dextrose or 0.9% saline. The results are shown in Table 3 below. Table 3

Example 3 - Composition comprising niclosamide and saline

Niclosamide (5 g) was combined with saline solution 0.9% w/v (ad to 100 ml) at 30 degrees C and agitated to prepare a suspension of niclosamide 5% w/v in saline (Sample 5).

Example 4 - Administration of niclosamide compositions

Niclosamide compositions were prepared in accordance with the method described in Examples 2 and 3. Subjects (pigs, approximately 30 kg in weight), with in-dwelling venous catheters for blood sampling, were administered a niclosamide composition having the composition of Sample 1 described in Table 2 (5% w/v niclosamide in polysorbate 80) at a dosage of 3 mg/kg niclosamide. After four hours, the subjects were administered a second dose of 1.5 mg/kg niclosamide.

Blood samples were taken at approximately 5 to 30 minute intervals for approximately 8 to 10 hours. Data relating to levels of niclosamide in blood plasma (ng/ml) for each dosage over time are shown in Figures la and lb.

Example 5 - Suppository compositions Suppository compositions were prepared according to the following methodology.

Formulations were prepared comprising 10, 20, 30, 40, and 50% w/w niclosamide mixed with polyethylene glycol 1450 (PEG 1450; average molecular weight 1,450) and polyethylene glycol 4000 (PEG 4000; average molecular weight 3,500-4,500) at 60°C and moulded into 3 gram suppositories. Another set of formulations containing a carrier composition of 10% polysorbate 80 and 90% polyethylene glycol 1450 and 4000 were used to make suppositories containing 10, 20, 30, 40, and 50% w/w of niclosamide. Niclosamide suppository formulations were prepared having the compositions described in Table 4.

Example 6 - Oral administration

For this Example, solubilised niclosamide compositions having the composition of Sample 4 in Table 2 were prepared according to the method described in Example 2. Niclosamide suspensions were prepared according to the method described in Example 3.

Subjects (Pigs, approximately 30 kg in weight), with in-dwelling venous catheters for blood sampling, were orally administered a dose of either the solubilised niclosamide composition or the niclosamide suspension, via gastric gavage, at a dosage of 5 mg/kg niclosamide.

Blood samples were taken at approximately 5 to 30 minute intervals for approximately 8 to 10 hours. Data relating to levels of niclosamide in blood plasma (ng/ml) over time are shown in Figure 2.

Example 7 - Oral administration

For this Example, solubilised niclosamide compositions having the composition of Sample 4 were prepared according to the method described in Example 2 (see Table 2). Niclosamide suspensions were prepared according to the method described in Example 3.

Two groups of six pigs weighing approximately 30 kg with in-dwelling venous catheters for blood sampling, were orally administered either the solubilised niclosamide composition or the niclosamide suspension, via gastric gavage, at a niclosamide dosage of either 9 mg/kg or 15 mg/kg.

Blood samples were taken at approximately 30-minute intervals for approximately 12 hours post dosing. Data relating to levels of niclosamide in blood plasma (ng/ml) for each dosage are shown in Table 5 and Figure 3.

Table 5

Example 8 - Antimicrobial activity of compositions

The antimicrobial activity of solubilised niclosamide compositions were investigated against strains of Staphylococcus. Most strains were obtained from bovine milk samples taken from cows suffering from mastitis.

The methodology from CLSI Performance Standards - Veterinary Edition was followed. (See: CLSI. VetOl Performance Standards for Antimicrobial Disk and Dilution Susceptibility Tests for Bacteria Isolated From Animals; Approved Standard - Fifth Edition; and CLSI Vet08 Performance Standards for Antimicrobial Disk and Dilution Susceptibility Tests for Bacteria Isolated From Animals; Second Informational Supplement - Fifth Edition).

Paper discs were impregnated with approximately 30 micrograms of a composition comprising the solubilised niclosamide composition in polysorbate 80 and polyethylene glycol 400, having the composition of Sample 4. The discs were placed on an agar plate inoculated with a bacterial strain and incubated for 18-24 hours at 37 °C in air. The sizes of the zones of inhibition are shown in Table 6 below for each strain.

Table 6

REFERENCES

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Phadke et al., "COVID-19 treatment by repurposing drugs until the vaccine is in sight", Drug Dev Res., 2020, 1-3.

Wu et al., "Design and evaluation of injectable niclosamide nanocrystals prepared by wet media milling technique", Drug Dev Ind Pharm, 2015, 41(9), 1416-1424.

Chen et al., "Niclosamide: Beyond an antihelminthic drug", Cellular Signalling, 41, (2018), 89-96. Zhou et al., "Broad Spectrum Antiviral Agent Niclosamide and Its Therapeutic Potential", ACS Infect. Dis., 2020, 6, 909-915.

Schwartzberg et al., "Safety of Polysorbate 80 in the Oncology Setting", Adv Ther, (2018), 35, 754-767.