WO2023275190A1

WO2023275190A1 - Soft gel capsule

Info

Publication number: WO2023275190A1
Application number: PCT/EP2022/067980
Authority: WO
Inventors: Kurt Ingar Draget; Marit Otterlei; Per Bruheim
Original assignee: Norwegian University Of Science And Technology
Priority date: 2021-06-30
Filing date: 2022-06-29
Publication date: 2023-01-05
Also published as: GB202109464D0

Abstract

A soft gel capsule comprising a gel shell encapsulating a core water-in-oil emulsion, said water-in-oil emulsion comprising a continuous phase and a disperse phase, said water-in-oil emulsion comprising at least 5 wt% water and at least one active component; wherein the continuous phase of the water-in-oil emulsion is a solid at a temperature of 23ºC or less and melts at a temperature of between 23 and 37 ºC.

Description

Soft gel capsule

This invention relates to soft gel capsules in which the core fill is a water-in- oil emulsion, in particular a water-in-oil emulsion in which the continuous phase is solid at room temperature but liquefies at body temperature. The soft gel capsules of the invention are ideal for carrying medically interesting but organoleptically unpalatable aqueous compositions such as garlic extract.

Background

Garlic supplements have gained increased scientific interest recently and a number of scientific publications show a clear positive health benefit from the organo-sulfuric compounds (OSCs) present in garlic. Petrovic et al, for example, reports the anti-cancer potential of fresh garlic extract (Nutrients 2018, 10(4), 450). These observations have led to a number of over the counter garlic supplement products in health food shops. However, the vast majority (if not all) of these products lack biological activity.

The present inventors have appreciated that these products invariably involve dried garlic compositions, typically freeze dried garlic compositions, to avoid the taste and smell of garlic. Because OSCs are highly volatile, these compounds are removed during the drying process and this is shown to reduce the biological activity (Petrovic et al, Nutrients 2018, 10(4), 450). OSCs are also unstable during storage if not immobilized due to evaporation and/or oxidation. Thus, after freeze drying, and/or long time storage, most of the OSCs are removed, and the product isn’t efficacious.

Figure 1 is a study where the amount of volatile OSCs are detected using GC-MS in the freshly made crude garlic extract (CGE) and commercial garlic products. It can clearly be seen that the content of OSCs in freeze dried commercial products, such as products by Kwai and Weissin, as well as in aged garlic extract, Kyolic, is different from CGE. The biological activity of garlic extract is not linked to one, but multiple OSCs (Nutrients 2018, 10(4), 450) so this reduction in OSCs reflects a significant loss of efficacy. The corresponding biological activities of CGE, Kwai, Weissin and Kyolic are compared in Figure 2-5. These figures show that the highest biological activity, i.e. cancer growth inhibiting properties, is found in crude garlic extract (CGE, 100% inhibition, Figure 2). Addition of CGE diluted 1 :3000 to the cancer cells completely blocked their growth. The same dilution of Weissin (Figure 3) or Kylolic (Figure 5) did not reduced cancer cell growth at all, while Kwai had some activity and reduced the cancer cell growth with 45% (after 100 hours).

WO2020/252346 discloses a dihydromyricetin (DHM) formulation, comprising dihydromyricetin (DHM) and a permeabilizer comprising a fatty acid salt and/or a fatty acid.

The present inventors therefore sought a way to provide a consumer with a garlic extract in which the active components were not removed in a drying or aging process.

The key OSC compounds are water soluble and hence are readily extracted into aqueous solution. Of course, the problem with an aqueous garlic extract is the taste and smell of garlic. No consumer will take a supplement that smells and tastes of garlic as such a product is distinctly unpleasant. This means that the aqueous extract of garlic needs to be presented in a form where the taste and smell of garlic are avoided but without losing the active agents.

The present inventors therefore considered encapsulation of the aqueous extract to prevent the consumer smelling or tasting the product whilst retaining the active components. Of course, encapsulating an aqueous extract is not simple.

One option for encapsulation is a soft gel capsule but soft gel capsules become unstable when there is more than 5% water in the filling material. To make capsules with only 5% aqueous garlic extract is not practical as the consumer then must take >10 capsules a day to cover a garlic intake of >2 cloves per week (recommended dose). Larger water content in an oil in water emulsion would dramatically weaken the soft gel capsule leading to leakage and release of the capsule (garlic) contents.

The use of a hard capsule is also precluded as the water would soften the hard shell and again leakage would occur.

There remains a need therefore to devise a dosage form for delivering an aqueous garlic extract comprising OSCs to a consumer without the taste and smell of garlic.

The present inventors have now found that aqueous garlic extracts can be administered to a consumer in soft gel capsule form if the core fill material is a water-in-oil emulsion which is stabilized by a continuous phase (lipid phase) which is solid at room temperature but that will melt at e.g. around 30 °C to release its contents at physiological temperatures after ingestion and when entering the ventriculus or lower intestine if coated with polymers.

In this way the consumer eats a product without the taste and odour of garlic as the aqueous garlic extract is held within a solid fill inside the capsule, but the active components within the aqueous extract are released in liquid form in the body. If the continuous phase remains solid once eaten then release of the active components within the aqueous garlic extract is reduced. A further interesting effect of the invention is that when an emulsion is prepared (and hence break up the continuous garlic phase into droplets) both the smell and taste of garlic are strongly reduced.

In this scenario, the lipid is likely to be released slowly and low down in the small intestine in a rather uncontrollable manner. Pancreatic lipases will be required to break down the triglycerides. The tailoring of the emulsion of the invention to melt at physiological temperature ensures maximum bioavailability as the melted contents pass through the pyrolic sphincter.

Moreover, whilst this invention was developed with a view to resolving issues surrounding garlic extracts, the invention proposed herein is suitable for encapsulating other active ingredients which suffer from the same issues. The general principle of providing a solid water-in-oil emulsion that melts upon eating is generally applicable therefore to other active agents.

The use of a solid water-in-oil emulsion within a soft gel capsule is a new concept although in US3376199, the inventors discuss the administration of polio vaccine in a soft gel capsule incorporating a viscous water-in-oil emulsion core.

The continuous phase is viscous to prevent migration of the water within the emulsion to the soft gel shell.

The continuous phase in this patent is not however solid and does not undergo melting at elevated temperature. The inventors perceive that this solution still risks migration of the aqueous phase to the capsule shell and there is no suggestion of the benefit of having a continuous phase that becomes less viscous with heat and therefore aids in the release of the active in the capsule.

A key requirement of the present invention therefore is the avoidance of water droplets that might causing damage to the capsule shell. Damage avoidance is most successful when the droplets are fixed within the crystalline lipid phase. Increasing the viscosity of the continuous phase reduces droplet mobility but does not prevent movement. Summary of Invention

Viewed from one aspect the invention provides, a soft gel capsule comprising a gel shell encapsulating a core water-in-oil emulsion, said water-in-oil emulsion comprising a continuous phase and an aqueous disperse phase, said water-in-oil emulsion comprising at least 5 wt% water and at least one active component; wherein the continuous phase of the water-in-oil emulsion is a solid at a temperature of 23°C or less and melts at a temperature of between 23 and 37 °C.

Alternatively viewed, the invention provides a soft gel capsule comprising a gel shell encapsulating a core water-in-oil emulsion, said water-in-oil emulsion comprising a continuous phase and an aqueous disperse phase, said water-in-oil emulsion comprising at least 5 wt% water and at least one active component; wherein the water-in-oil emulsion is a solid at a temperature of 23°C or less and melts at a temperature of between 23 and 37 °C.

Viewed from one aspect the invention provides, a soft gel capsule comprising a gel shell encapsulating a core water-in-oil emulsion, said water-in-oil emulsion comprising a continuous phase and an aqueous disperse phase, said water-in-oil emulsion comprising at least 5 wt% water and at least one garlic extract; wherein the continuous phase of the water-in-oil emulsion is a solid at a temperature of 23°C or less and melts at a temperature of between 23 and 37 °C.

Viewed from another aspect the invention provides a soft gel capsule as hereinbefore defined for use in the prevention or treatment of cancer, hypertension and high cholesterol.

Viewed from another aspect the invention provides the use of a soft gel capsule as hereinbefore defined in the manufacture of a medicament for the prevention or treatment of cancer, hypertension and high cholesterol. Viewed from another aspect the invention provides a method of treating or preventing of cancer, hypertension and high cholesterol comprising administering to a patient in need thereof a soft gel capsule as hereinbefore defined.

Viewed from another aspect the invention provides a process for the preparation of a soft gel capsule as hereinbefore defined comprising i) preparing a liquid water-in-oil emulsion comprising a continuous phase and an aqueous disperse phase by combining a) an aqueous composition comprising at least one active agent and b) compounds to form a liquid continuous phase at a temperature of at least 25°C; ii) filling a soft gel shell with said emulsion from step (i); and iii) cooling the formed soft gel capsule so that the continuous phase of the water in oil emulsion solidifies.

Viewed from another aspect the invention provides a soft gel capsule obtained by a process comprising i) preparing a liquid water-in-oil emulsion comprising a continuous phase and an aqueous disperse phase by combining a) an aqueous composition comprising at least one active agent and b) compounds to form a liquid continuous phase at a temperature of at least 25°C; ii) filling a soft gel shell with said emulsion from step (i); and cooling the formed soft gel capsule so that the continuous phase of the water in oil emulsion solidifies.

Detailed Description of Invention

This invention relates to a soft gel capsule in which the filling in the capsule is a solid water-in-oil emulsion at room temperature. The soft gel capsule has a shell which is conventional. Ideally, the soft gel capsule filling consists of the water- in-oil emulsion of the invention.

The water-in-oil emulsion has a disperse phase (the aqueous phase) and a continuous phase (the oil phase). Typically there is an excess of the continuous phase. For example, the weight ratio of continuous phase to aqueous phase is 1 : 1 to 5:1 , such as 2:1 to 5:1 , preferably 2.5:1 to 4:1.

It is therefore preferred if the continuous oil pahse forms 55 wt% to 90 wt% of the water-in-oil emulsion, such as 60 to 80 wt%.

It is therefore preferred if the aqueous phase forms 10 wt% to 45 wt% of the water-in-oil emulsion, such as 20 to 40 wt%.

Continuous phase The continuous phase is one that is solid at room temperature but melt at physiological temperature. It is preferably based on a blend of fats, oils or lipids. Crucially, the continuous phase should be solid at room temperature or below, i.e. a solid at 23°C or less. The continuous phase should melt to become a liquid at a temperature between room temperature and physiological temperature, e.g. between 23 and 37°C.

Any pharmaceutically or nutraceutically acceptable continuous phase components may be used which provide the required melting profile. The continuous phase may comprise a single material or a blend of different materials. Preferably, the continuous phase comprises a blend of oils and fats. In general, lipid food grade fatty acid sources are used in the invention.

Preferred compounds suitable for use in the continuous phase are long chain fatty acids or esters such as mono-, di- and triacylglycerides and phospholipids, for example plant or animal oils, especially plant and marine animal oils.

Fats and oils that can be used may be saturated or unsaturated, such as polyunsaturated or monounsaturated. Fatty acids and fatty acid esters of use in the invention may comprise 8 to 24 carbon atoms in the fatty acid portion, such as 10 to 20 carbon atoms. Typically, carbon chains have an even number of carbon atoms.

It is most preferred if the continuous phase comprises a blend of fats and oils. Herein a fat is deemed a compound that is solid at room temperature and an oil a compound that is liquid a room temperature. By mixing fat and oil it is possible to obtain a composite that has the melting characteristics defined herein. It is most preferred if the continuous phase comprises a blend of solid fatty acids or esters thereof and liquid fatty acids or esters thereof.

Suitable oils are those that have a melting points or crystallisation temperature of up to 24 °C, such as 0 to 24 °C.

Suitable fats are those that have a melting point of 25 °C or more, such as 25 to 100°C. Ideally, the continuous phase comprises a blend of solid fatty acids or esters thereof having a melting point from 25 to 100°C and liquid fatty acids or esters thereof having a melting point up to 25°C.

Alternatively, oils of the invention have a crystallization temperature of 24 °C or below, such as 0 to 24°C. Fats of the invention have a crystallization temperature 25 °C or more, such as 25 to 100 °C. The crystallisation temperature of various fats and oils is illustrated in the examples. ln order to ensure that the water-in-oil emulsion has the appropriate melting point, we can also consider that the blend of oils and fats used as the continuous phase has a crystallization point in the range of 23 and 37°C.

The weight ratio of solid fat to liquid oil in the continuous phase is preferably such that the fat is in excess. The weight ratio may be 5:1 to 1 :1 fat to oil, such as 4:1 to 1.5:1. In one embodiment therefore the continuous phase comprises 50 to 80 wt% fat and 20 to 50 wt% oil. In one embodiment therefore the continuous phase comprises 50 to 80 wt% solid fatty acids or esters thereof and 20 to 50 wt% liquid fatty acids or esters thereof

In one embodiment, the continuous phase may comprise an omega-3, omega-6 or omega-9 essential fatty acid or ester thereof, especially omega-3 essential fatty acid or ester thereof. In this way the oil phase itself is a highly bioavailable source of nutrient lipids.

Examples of omega-3 acids include a-linolenic acid (ALA), stearidonic acid (SDA), eicosatrienoic acid (ETE), eicosatetraenoic acid (ETA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), docosahexaenoic acid (DHA), tetracosapentaenoic acid and tetracosahexaenoic acid.

Examples of omega-6 acids include linoleic acid, gamma-linolenic acid, eicosadienoic acid, dihomo-gamma-linolenic acid (DGLA), arachidonic acid (AA), docosadienoic acid, adrenic acid, docosapentaenoic acid, and calendic acid.

Examples of omega-9 acids include oleic acid, eicosenoic acid, mead acid, erucic acid and nervonic acid.

In one embodiment, the continuous phase comprises free essential fatty acids (or physiologically tolerable salts thereof) and/or monoacylglycerides of essential fatty acids to facilitate essential fatty acid uptake from the gut.

Where a free fatty acid is used, this is preferably wholly or partially in salt form.

The oil component of the continuous phase is most conveniently provided as a medium chain triglyceride (MCT). Medium-chain triglycerides (MCTs) are triglycerides with two or three fatty acids having an aliphatic tail of 6-12 carbon atoms, i.e., medium-chain fatty acids (MCFAs). Rich food sources for commercial extraction of MCTs include palm kernel oil and coconut oil. Fatty acids that might be present include caproic acid, caprylic acid, capric acid and lauric acid.

The solid fat component of the continuous phase is most conveniently provided by higher fatty acids or fatty acid esters, such as higher fatty acid triglycerides. Suitable triglycerides are those with two or three fatty acids having an aliphatic tail of 14-24 carbon atoms. Suitable fatty acids present include myristic, palmitic, stearic and oleic acid. Beeswax may also be used.

The person skilled in the art familiar with these fats and oils can devise a blend that meets the melting requirements of the invention.

One particular solution involves the combination of coconut fat and coconut oil.

Surfactant

The water-in-oil emulsion may contain an emulsifier/surfactant as is well known in the art. There might be 0.1 to 3.0 wt% surfactant, such as 0.1 to 2.0 wt% surfactant, such as 0.2 to 0.8 wt% surfactant in the water-in-oil emulsion as a whole.

Suitable emulsifier/surfactants include physiologically acceptable surfactants such as anionic, non-ionic or zwitterionic surfactants. Suitable surfactants include ethoxylates such as fatty alcohol ethoxylates, narrow-range ethoxylate, octaethylene glycol monododecyl ether, pentaethylene glycol monododecyl ether, and fatty acid ethoxylates.

Fatty acid ethoxylates are a class of versatile surfactants, which combine in a single molecule the characteristic of a weakly anionic, pH-responsive head group with the presence of stabilizing and temperature responsive ethylene oxide units.

Other surfactants include ethoxylated amines and/or fatty acid amides, polyethoxylated tallow amine, cocamide monoethanolamine, cocamide diethanolamine, terminally blocked ethoxylates, poloxamers, fatty acid esters of polyhydroxy compounds, fatty acid esters of glycerol, glycerol monostearate, glycerol monolaurate, fatty acid esters of sorbitol, sorbitan monolaurate, sorbitan monostearate, sorbitan tristearate, Tweens, fatty acid esters of sucrose, alkyl polyglucosides, and polyglycerol polyricinoleate. The use of polyglycerol polyricinoleate (PGPR) is especially preferred.

Surfactants of interest ideally have low HLB values. Surfactants with low HLB values are more oil-soluble (lipophilic). These may have values in the range of 1.0 to 10, such as 2 to 7.

During the preparation of the water-in-oil emulsion the surfactant should be added to the continuous phase materials. The inner filling (or core) of the soft gel capsule comprises, preferably consist of, the water-in-oil emulsion. The water-in-oil emulsion contains at least 10 wt% water, such as at least 15 wt% water, e.g. 10 to 30 wt% water, such as 15 to 25 wt% water.

The water-in-oil emulsion is prepared using conventional techniques at a temperature at which it is a liquid. The liquid water-in-oil emulsion can then be filled into the capsules and cooled to its solid form. Ideally, the temperature at which filling occurs is as low as possible to prevent destabilisation of the gelatin capsule during filing. Thus, ideally the water-in-oil emulsion is filled at a temperature just above its crystallisation temperature, e.g. 30 to 40 ‘C.

Active Agent

The concept of using a water-in-oil emulsion that is solid at room temperature but melts at physiological temperature is a generally applicable concept to any water soluble active agent or any active agent that can be provided in water, especially one which is unpleasant in terms of taste and smell. The active agent can be pharmaceutical or nutraceutical. The term active agent herein therefore refers to a biologically active agent.

It is also possible to administer both water and lipid soluble active agents using the product of the invention. The invention therefore also covers such combination products.

As long as the pharmaceutical or nutraceutical active agent is inert towards the water-in-oil emulsion components and doesn’t degrade in water then there is no limit to the nature of the active agent. Active agents such as peptides are of specific interest for example.

The invention however is primarily directed towards a garlic supplement.

The aqueous phase of the water-in-oil emulsion preferably comprises a garlic extract.

In particular, that garlic extract should comprise organosulphur compounds (OSCs) which are extracted from garlic pulp in an aqueous extraction process.

Such compounds include allicin which is a thiosulfinate compound, S-(prop-2-en-1- yl) prop-2-ene-1-sulfinothioate.

Allicin is however quite unstable and may decompose to a series of further OSC compounds. Other OSC compounds that may be present in the garlic extract of the invention include diallyl sulphide, diallyl disulphide, diallyl trisulphide, ajoene, S-allylmercapto-cysteine, diallyl tetrasulfide, S-allylcysteine, and allyl methyl sulphide.

Allicin and these other OSC compounds are created in garlic when the garlic sustains tissue damage. The enzyme allinase in garlic is stimulated to generate allicin and hence the potential for the formation of further OSC compounds when the garlic tissue is damaged in some way, e.g. ground, chopped, chewed etc.

OSC compounds are formed therefore when the garlic is ground to a pulp before an aqueous extraction or aqueous ethanol extraction process. It is particularly preferred if the garlic extract of the invention contains high levels of diallyl disulphide or isomers thereof. The largest OSC component therefore of the garlic extract of the invention is preferably diallyl disulphide or an isomer thereof.

The garlic extract preferably comprises methyl 2-propenyl trisulfide, 3-vinyl- 1 ,2-dithiacyclohex-5-ene, triallyl trisulphide or an isomer thereof and allyl methyl disulphide.

Ideally the levels of one or more, such as all, of these components is higher than the content of diallyl sulphide and/or allyl methyl sulphide.

The garlic extract of use in the present invention can readily be obtained simply by grinding garlic cloves, e.g. in a blender, and adding water or ethanol and water (e.g. with up to 40 wt% ethanol to 60 wt% water). Extraction of the relevant components of garlic can be achieved in as little as two hours at room temperature. This forms a further aspect of the invention. It was previously believed that extracting the OSC compounds in garlic required a long extraction process of up to 21 days at refrigerator temperature. In fact, the process can be achieved rapidly and at room temperature.

Viewed from another aspect therefore the invention provides a process for the extraction of organosulphur compounds from garlic comprising: i) grinding garlic to form a pulp; ii) adding water or ethanol and water at a temperature of 10 to 30°C to said pulp; iii) after a minimum of 1 .5 hrs, separating the liquid component from the pulp.

If the extraction process is cooled then the extraction may take longer, e.g.

21 days at 4°C. This is less attractive. The use of water alone as extraction solvent is preferred. Grinding of the garlic cloves can be achieved in any conventional blender, e.g. a food blender.

The proportion of extraction solvent used may vary but conveniently, the skilled person might use between 0.5 to 2 ml of water (or water/ethanol) per clove of garlic, such as 0.75 to 1.0 ml per clove. After extraction the aqueous phase can be separated from the pulp by any technique such as filtration or centrifuge. The amount of OSC components in the aqueous phase is challenging to measure but is sufficient to inihbit growth of JJN3 multiple myeloma cancer cells at dilution below 1-3000.. The aqueous garlic extract of the invention might utilise 0.7 g garlic / ml. of water.

It should be noted that stomach acid inactivates the allinase enzyme that is required to generate the OSC compounds in garlic. The activity of the crude garlic extract, i.e. OSCs, is however, stable after treatment with HCI, pH1 (Petrovic et al. Nutrients 2018, 10(4), 450). Therefore, simply eating raw garlic is not as effective in terms of active agent delivery as taking the soft gel capsules of the invention. The OSC compounds are only generated when chewing begins and tissue damage starts. If chewed therefore and quickly swallowed, the allinase enzyme is destroyed on reaching the stomach. The invention herein allows more OSC compounds to develop and obviously avoids the deeply unpleasant requirement to eat raw garlic.

The preparation of the water-in-oil emulsion can be achieved using known techniques. Conveniently, the components forming the continuous phase are combined with the surfactant. The mixture should be heated such that the continuous phase is liquid, e.g. at a temperature of 30 to 60°C. The aqueous disperse phase containing the desired active components can then be added to the liquid continuous phase with stirring.

This blend can then be homogenised. Homogenization reduces the size of any globules in the emulsion to extremely small particles and distributes them uniformly throughout the fluid. The formed water-in-oil emulsion is maintained in liquid form for filling into soft gel capsules.

It is within the scope of the invention to add standard additives to the emulsion, such as antioxidants or antimicrobial agents etc to help prevent degradation of any active agents within the emulsion.

Soft gel shell

The water-in-oil emulsion is encapsulated within a soft gel shell to for the soft gel capsule of the invention. The soft gel shell is conventional and uses a physiologically tolerable gelling agent, e.g. a hydrocolloid such as gelatin, alginate, carrageenan or a pectin. Such gelling agents and their gel-forming properties are well known. The use of gelatin is especially preferred in the invention. Besides water and the gelling agent, soft gel shell may comprise a plasticiser such as sorbitol, glycerine, triethyl citrate or a non-glycerin plasticizer. The soft gel shell may also contain an opacifier.

The type of plasticizer and amount used will affect many of the characteristics of the finished product including dissolution or disintegration, hardness, and stability.

The soft gel shell may also contains standard components to improve its taste or appearance such as a colouring and/or a sweetener such as a sugar alcohol.

Typical shell formulations contain (w/w) from about 40-50% gelling agent, about 20-30% plasticizer, and about 30-40% water. Most of the water is subsequently lost during capsule drying.

Any soft gel capsule of the invention may also contain other interesting ingredients as long as these do not disrupt the integrity of the capsule. These ingredients include vitamins, minerals, pH modifiers, viscosity modifiers, antioxidants, colorants, flavours, etc. as desired.

The garlic extract that is the main focus of the invention may be combined therefore with another active agent. The other active agent can be located either within the shell or water-in-oil emulsion core.

Capsule production Production of the soft gel capsule of the invention uses conventional manufacturing technology. The ingredients for the shell are combined to form a molten mass using in either a cold melt or a hot melt process. The prepared gel masses are transferred to preheated, temperature-controlled, jacketed holding tanks where the gel mass is aged at 50-60°C until used for encapsulation.

Cold Melt Process

The cold melt process generally involves mixing gelling agent with plasticizer and chilled water and then transferring the mixture to a jacket-heated tank. Typically, gelling agent is added to the plasticizer at ambient temperature (18- 22°C). The mixture is cooked (57-95°C) under vacuum for 15-30 minutes to a homogeneous, deaerated gel mass. Additional shell additives can be added to the gel mass at any point during the gel manufacturing process or they may be incorporated into the finished gel mass using a high torque mixer.

Hot Melt Process

The hot melt process generally involves adding, under mild agitation, the gelling agent to a preheated (60-80°C) mixture of plasticizer and water and stirring the blend until complete melting is achieved. While the hot melt process is faster than the cold melt process, it is less accurately controlled and more susceptible to foaming and dusting.

Encapsulation

Soft gel capsules are typically produced using a rotary die encapsulation process. The gel mass is fed either by gravity or through positive displacement pumping to two heated (e.g. 48-65°C) metering devices. The metering devices control the flow of gel into cooled (10-18°C), rotating casting drums. Ribbons are formed as the cast gel masses set on contact with the surface of the drums.

The ribbons are fed through a series of guide rolls and between injection wedges and the capsule-forming dies. A food-grade lubricant oil is applied onto the ribbons to reduce their tackiness and facilitate their transfer. Suitable lubricants include mineral oil, medium chain triglycerides, and soybean oil. The filling is then fed into the encapsulation machine by gravity. According to a preferred embodiment, the fill material and the gel mass are processed into soft gelatin capsules using the rotary die method. During encapsulation the ribbon is lubricated on both sides with medium chain triglycerides (MCT) and the outer side of the capsule is lubricated also with medium chain triglycerides/lecithin. The fill material is cooled (approximately 30 ± 5°C) after emulisification and mixed prior and during encapsulation and the process is set to deliver the required amount of fill material. The filled capsules are then cooled to solidify the continuous phase of the water-in-oil emulsion. Capsules can then be dried and packaged.

The amount of filling in each capsule is typically around 0.5 ml and 6 to 8 capsules is roughly equivalent to the active content of one garlic clove. Taking 3 capsules a day or more therefore results in a weekly intake equivalent to the recommended 2 cloves of garlic per week.

Capsules can be a standard oblong shape.

Internal testing suggests that the OSC compounds are stable for at least 6 months in the aqueous extract and that the capsules of the invention have a shelf life of at least 12 weeks.

It may be preferably to store the capsules of the invention in a refrigerator.

In a further embodiment, the soft gel capsules of the invention may be provided with an enteric coating. Materials used for enteric coatings include waxes, shellac, plastics, and plant fibers. Capsules may be pan coated with a suitable outer layer, e.g. for organoleptic purposes, such as a sweetener coating.

The capsules might also be coated with additional emulsion, solidified onto the outside of the capsule with optional subsequent pan coating with an outer layer.

Viewed from another aspect the invention relates to a process comprising

A) blending garlic cloves to form a pulp and adding 0.2 to 2.0 ml water per clove of garlic to the pulp; filtering the liquid from the pulp to form an aqueous garlic extract;

B) melting coconut fat and coconut oil in a ratio of 3: 1 to 1 :3 and polyglycerol polyricinoleate at a temperature of at least 35 °C;

C) adding the aqueous garlic extract prepared in step (A) to the product of step B) and homogenizing to form a liquid water-in-oil emulsion having a liquid continuous phase and a disperse phase comprising said aqueous garlic extract;

D) filling gelatin soft gel capsules with said water-in-oil emulsion and cooling to solidify the continuous lipid phase of said water-in-oil emulsion. It will be appreciated that steps A) and B) can be carried out in any order or simultaneously.

Medical Applications

The garlic extract encapsulated within the soft gel capsules of the invention is suggested in the literature as having anticancer properties, often in combination with secondary therapy. Petrovic et al, 2018 Nutrients, 10(4), 450 suggests that a garlic extract does not inhibit, but rather increases, the anti-cancer activity of common chemotherapeutics (docetaxel, cisplatin and gemcitabine) or targeted therapies (kinase inhibitors). These effects have particularly been noted in vivo in breast cancer models. Other cancers of interest include gastric cancer and prostate cancer.

It has been suggested that eating 2 cloves of raw garlic a week offers benefits in terms of hypertension and reduction in cholesterol level. Patients with dyslipidemia who consumed garlic experienced benefits. Diabetic patients with longer durations of garlic intake experienced more benefits in terms of fasting blood glucose (FBG), HbA1c, and serum fructosamine than healthy participants, and garlic intake was associated with blood pressure reduction in hypertensive patients.

The invention will now be described with reference to the attached non limiting examples and figures.

Description of the Figures

Figure 1 shows the levels of various OSCs in a Crude Garlic Extract (CGE - abbreviated as C) made according to the protocols in example 1 , and the OSCs levels in three commercial garlic products: two freezed dried tablets, Weissin (100% allicin- containing vegetable capsules, Allicin International Limited, Rye, East Sussex, TN31 7NY UK, abbreviated as W) and Kwai (high concentrated garlic tablets, Klosterfrau Berlin, Germany, abbreviated as Kw), and in an aged aquas garlic extract, Kyolic (Aged Garlic ExtractTM, Wakunaga of America Co. Ltd - abbreviated as Ky)).

Figure 2 shows growth inhibiting effects on the multiple myeloma cancer cell line JJN3 of crude garlic extracts (CGE, corresponds to 0.7 g garlic /mL) according to the protocols in example 1 diluted from 1 :2000 to 1 :5000 in growth media compared to same amount of added milliQ water. Growth is measured as absorbance at 24, 48, 72 and 96 hours after addition of agent using an MTT-assay as described previously (Petrovic et al, Nutrients 2018, 10(4), 450).

Figure 3 shows growth inhibiting effects on the multiple myeloma cancer cell line JJN3 of Weissin-solution made to correspond to 0.7 g garlic /mL diluted from 1 :2000 to 1 :5000 in growth media compared to same amount of added milliQ water. Growth is measured as absorbance at 24, 48, 72 and 96 hours after addition of agent using an MTT-assay as described previously (Petrovic et al, Nutrients 2018, 10(4), 450). The concentrations of the Weissin-solution is based in information from manufacturer, 1 tablet correspond to 180 mg garlic. The tablets were dissolved in water, incubated for 15 minutes in an ultrasound bath and 45 min at room temperature before the solution was cleared by centrifugation (13,400 rpm).

Figure 4 shows growth inhibiting effects on the multiple myeloma cancer cell line JJN3 of Kwai-solution made to correspond to 0.7 g garlic /mL diluted from 1 :2000 to 1 :5000 in growth media compared to same amount of added milliQ water. Growth is measured as absorbance at 24, 48, 72 and 96 hours after addition of agent using an MTT-assay as described previously (Petrovic et al, Nutrients 2018, 10(4), 450). The concentrations of Kwai-solution is based in information from manufacturer, 1 tablet correspond to 300 mg garlic. The tablets were dissolved in water, incubated for 15 minutes in an ultrasound bath and 45 min at room temperature before the solution was cleared by centrifugation (13,400 rpm).

Figure 5 shows growth inhibiting effects on the multiple myeloma cancer cell line JJN3 of the aged garlic extract Kyolic diluted from 1 :2000 to 1 :5000 in growth media compared to same amount of added milliQ water. Growth is measured as absorbance at 24, 48, 72 and 96 hours after addition of agent using an MTT-assay as described previously (Petrovic et al, Nutrients 2018, 10(4), 450).

Figure 6 shows testing of different wt% water and emulsifier contents. The experiment shows that the solid emulsion is stable down to low levels of PGPR and up to 30% water.

Example 1 - aqueous garlic extract

An aqueous garlic extract was prepared by blending garlic cloves in a food blender and adding 0.8 ml water per clove of garlic to the blending pulp. After 2 hrs at room temperature the liquid was filtered from the pulp. This aqueous garlic extract was subjected to analysis to determine its OSC content. The aqueous garlic extract was found to contain high levels of OSCs especially diallyl disulphide and isomers thereof (see Figure 1). Compared to other extracts, the aqueous garlic extract showed reduced levels of diallyl sulphide and alkyl methyl sulfate.

The aqueous garlic extract was then tested against the multiple myeloma cancer cell line JJN3 diluted from 1 :2000 to 1 :5000 in growth media compared to same amount of added milliQ water. Growth is measured as absorbance at 24, 48, 72 and 96 hours after addition of agent using an MTT-assay as described previously (Petrovic et al, Nutrients 2018, 10(4), 450).

The aqueous garlic extract offered excellent inhibition of cancer cells.

Example 2 - water in oil emulsion

110 g of coconut fat (i.e. coconut butter) was melted together with 55 g coconut oil and 0.82 g PGPR at 50 °C. After approximately 1 hour, the temperature was lowered to 40 °C. 41 g of the aqueous garlic extract prepared above in example 1 was added under stirring to the fat and oil mixture and the blend was homogenized using a ΊKA T18” basic homogenizer for 3 minutes (25 wt% aq. - 75 wt% oil).

Example 3 - Soft gel capsule filling

The resulting water-in-oil emulsion is filled into gelatin soft gel capsules whilst cooling to solidify the continuous lipid phase. Once solidified, the capsules can be stored, ideally at a temperature of less than 20°C.

Soft gel capsules may be produced by encapsulation using a Rotary Die Encapsulation process. Two flat ribbons of shell material are manufactured on the machine and brought together on a twin set of rotating dies. The dies contain recesses in the desired size and shape, which cut out the ribbons into a two- dimensional shape, and form a seal around the outside.

A pump delivers the dose of aqueous garlic extract material through a nozzle incorporated into a filling wedge whose tip sits between the two ribbons in between two die pockets at the point of cut out. The wedge is heated to facilitate the sealing process. The wedge injection causes the two flat ribbons to expand into the die pockets, giving rise to the three-dimensional finished product. After encapsulation, the soft gels are cooled and dried.

Example 4 Various further water-in-oil emulsions were prepared using different amounts of aqueous and oil phases (but the same relative amounts of coconut butter and oil) and PGPR additions as illustrated in figure 6. All these emulsions were stable and solid. Example 5

Crystallization temperatures of various lipids and lipid combinations were measured applying a Kinexus Ultra+ general purpose rheometer equipped with a 40 mm roughened parallel plate measuring geometry, 1 Hz frequency, 0.05% strain and a temperature gradient of 0.5C/min. Crystallization/setting temperature was identified as the temperature when the dynamic storage modulus changed with at least two orders of magnitude”

Materials: Coconut butter (“Delfia fat” from Mills AS, Oslo, Norway) and coconut oil (Sigma Life Sciences) as used in Example 2. Beeswax from Aldrich Chemistry.

Crystallization of various lipids and lipid mixtures

Claims

1. A soft gel capsule comprising a gel shell encapsulating a core water-in-oil emulsion, said water-in-oil emulsion comprising a continuous phase and a disperse phase, said water-in-oil emulsion comprising at least 5 wt% water and at least one active component; wherein the continuous phase of the water-in-oil emulsion is a solid at a temperature of 23°C or less and melts at a temperature of between 23 and 37 °C.

2. A soft gel capsule comprising a gel shell encapsulating a core water-in-oil emulsion, said water-in-oil emulsion comprising a continuous phase and a disperse phase, said water-in-oil emulsion comprising at least 5 wt% water and at least one garlic extract; wherein the continuous phase of the water-in-oil emulsion is a solid at a temperature of 23°C or less and melts at a temperature of between 23 and 37 °C.

3. A soft gel capsule as claimed in any preceding claim wherein the water-in-oil emulsion comprises a surfactant.

4. A soft gel capsule as claimed in claim 3 wherein the surfactant forms 0.1 to 3.0 wt% of the water-in-oil emulsion.

5. A soft gel capsule as claimed in any preceding claim wherein the water-in-oil emulsion comprises polyglycerol polyricinoleate (PGPR).

6. A soft gel capsule as claimed in any preceding claim wherein the water-in-oil emulsion comprises a blend of fatty acids or esters thereof.

7. A soft gel capsule as claimed in any preceding claim wherein the continuous phase of the water-in-oil emulsion comprises MCT oil.

8. A soft gel capsule as claimed in any preceding claim wherein the continuous phase of the water-in-oil emulsion comprises a saturated fat which is solid at 23°C or below.

9. A soft gel capsule as claimed in any preceding claim wherein the weight ratio of solid fat to liquid oil in the continuous phase is 5:1 to 1 :1 fat to oil, such as 4:1 to 1.5:1.

10. A soft gel capsule as claimed in any preceding claim wherein the water-in-oil emulsion comprises 55 to 90 wt% continuous phase.

11. A soft gel capsule as claimed in any preceding claim wherein the water-in-oil emulsion comprises 10 to 45 wt% water.

12. A soft gel capsule as claimed in any preceding claim wherein the gel shell comprises a hydrocolloid such as gelatin.

13. A soft gel capsule as claimed in any preceding claim wherein the active component comprises OSC compounds.

14. A soft gel capsule as claimed in any preceding claim wherein the capsules comprise an enteric coating.

15. A soft gel capsule as claimed in claim 1 to 14 for use in the prevention or treatment of cancer, hypertension and high cholesterol.

16. Use of a soft gel capsule as claimed in claim 1 to 14 in the manufacture of a medicament for the prevention or treatment of cancer, hypertension and high cholesterol.

17. A method of treating or preventing of cancer, hypertension and high cholesterol comprising administering to a patient in need thereof a soft gel capsule as hereinbefore defined.

18. A process for the preparation of a soft gel capsule as claimed in claim 1 to 14 comprising i) preparing a water-in-oil emulsion comprising a continuous phase and an aqueous disperse phase by combining an aqueous composition comprising at least one active agent and compounds to form a liquid continuous phase; ii) filling a soft gel shell with said emulsion from step (i); and iii) cooling the formed soft gel capsule so that the continuous phase of the water in oil emulsion solidifies.

19. A soft gel capsule obtained by a process comprising i) preparing a liquid water-in-oil emulsion comprising a continuous phase and an aqueous disperse phase by combining a) an aqueous composition comprising at least one active agent and b) compounds to form a liquid continuous phase at a temperature of at least 25°C; ii) filling a soft gel shell with said emulsion from step (i); and cooling the formed soft gel capsule so that the continuous phase of the water in oil emulsion solidifies.

20. A process comprising

B) melting coconut fat and coconut oil in a ratio of 3: 1 to 1 :3 and polyglycerol polyricinoleate at a temperature of at least 35 °C; wherein steps A) and B) are carried out in any order; C) adding the aqueous garlic extract prepared in step (A) to the product of step B) and homogenizing to form a liquid water-in-oil emulsion having a liquid continuous phase and a disperse phase comprising said aqueous garlic extract;

D) filling gelatin soft gel capsules with said water-in-oil emulsion and cooling to solidify the continuous lipid phase of said water-in-oil emulsion.