WO2010133761A1

WO2010133761A1 - Intravaginal delivery system comprising one or more therapeutically active substances capable of preventing and/or treating vaginal infections

Info

Publication number: WO2010133761A1
Application number: PCT/FI2010/050396
Authority: WO
Inventors: Christine Talling; Philip Owens; Gavin Wasserfall-Smith
Original assignee: Bayer Schering Pharma Oy
Priority date: 2009-05-19
Filing date: 2010-05-17
Publication date: 2010-11-25
Also published as: FI20095550A0

Abstract

The present invention is related to an intravaginal delivery system comprising one or more therapeutically active or a health-promoting substance capable of preventing and/or treating vaginal infections as well as giving protection against bacterial and fungal infections and/or against sexually transmitted diseases. Said substance(s) is/are selected form the group consisting of lactic acid, polylactic acid, glycolic acid, polyglycolic acid, ascorbic acid, folic acid and the reduced form thereof, p-aminobenzqic acid, alginic acid, sorbic acid, tartaric acid, edetic acid and salts of the acids, niacinamide, Bifidobacterium strains and Lactobacillus species. The delivery system consists of one or more compartments, one or each comprising a core and optionally a membrane encasing the core, said core and membrane essentially consisting of a same or different polymer composition.

Description

Intravaginal delivery system comprising one or more therapeutically active substances capable of preventing and/or treating vaginal infections

The present invention is related to an intravaginal delivery system comprising at least one compartment comprising a core and optionally a membrane encasing the core, said core and membrane essentially consisting of a same or different polymer composition, wherein at least one compartment comprises one or more therapeutically active or health-promoting substances capable of preventing and/or treating vaginal infections as well as giving the protection against bacterial and fungal infections and/or against sexually transmitted diseases.

BACKGROUND OF THE INVENTION

The resident microorganisms are known to be the main factors to maintain and stabilize the physiological environment in the vagina. Lactobacilli are the predominant microorganisms in the vaginal bacteria, and they play a major role in maintaining a healthy urogenital tract. They are capable of preventing adhesion and growth of pathogenic microorganisms through mechanisms that appear to involve secretion of anti-adhesion factors, hydrogen peroxide, bacteriocins lethal to pathogens and fermenting the glycogen derived from the decline of the atrophic vaginal mucosa, to lactic acid with release of hydrogen ions, the final result being the optimal pH value (Microb. Infect. 4, 319 324 (2002)).

Vaginal pH undergoes physiologically changes from birth to menopause, according to changes of ovarian steroids occurring during woman's life. Adequate levels of estrogens play a role in the trophism of vaginal mucosa, and estrogens increase the cellular content of glycogen. Several factors, such as sexual activity, oral contraceptives or systemic or local therapies may increase vaginal pH through different mechanisms. The change in the pH value may also be indicative to presence of disbalance in the vaginal environment such as systemic diseases or vaginal infections. The increase of vaginal pH above 4.0-4.5 is detrimental for the survival of Lactobacillus bacteria, but not for other micro organisms, especially for the pathogenetic microorganisms, whose replication on the contrary is favored by the absence of contraction exerted by lactobacilli.

Probiotic agents have been used to adjust or to maintain the normal vaginal pH value. For example, international patent application WO 2006/65873 relates to a fiber- reinforced composite ring containing ferrous gluconate or ferrous ascorbate as an active agent and acids, such as ascorbic and glycolic acids to maintain the vaginal pH below 6 and preferably at 3-4.5.

International patent application WO 2002/15832 relates to a non-hormonal intravaginal device and the vagina is maintained at a pH of about 5-6 by the addition of ascorbic acid to the matrix hydrogel. WO 2006/17341 relates to a vaginal device partly or completely coated or covered by or combined with a mucoadhesive composition containing a therapeutical agent and a health-promoting agent such as ascorbic acid.

The delivery of biological substances such as probiotics and bacteria in general are described for example in WO 2003/26687, US 20050152966 and US 20030096002, based on a swellable polymer matrices, in WO 2002/94224 based on biocompatible carbohydrate polymers associated with milk protein, and in WO 2005/74976 based on uncrosslinked starch.

The advantage of vaginal rings in general is that a woman is free from the necessity of remembering to take the medication daily. The ring-shaped structure is simple to apply, it is well tolerated and at any time the device can easily be removed and reinserted by the woman herself. Therefore the present invention provides an intravaginal delivery system, which can be used for the vaginal administration of a sufficient amount of a therapeutically active or a health-promoting substance capable of preventing and/or treating vaginal infections as well as giving the protection against bacterial and fungal infections and/or against sexually transmitted diseases. OBJECT OF THE INVENTION

The object of the invention is to provide an intravaginal delivery system comprising at least one compartment, said one or each compartment comprising a core and optionally a membrane encasing the core, the core and the membrane essentially consisting of a same or different polymer composition, wherein at least one compartment comprises one or more therapeutically active or health-promoting substances capable of preventing and/or treating vaginal infections as well as giving the protection against bacterial and fungal infections and/or against sexually transmitted diseases. The present invention especially provides an intravaginal delivery system for the administration of a representative of Lactobacillus species.

Another object of the invention is to provide an intravaginal delivery system for prevention and/or treatment of vaginal infections, e.g. bacterial vaginosis and (vulvo)vaginal candidiasis (vaginal yeast infections).

The invention further provides a method for preventing and/or treating vaginal infections as well as giving the protection against bacterial and fungal infections and/or against sexually transmitted diseases, which method comprises the steps of positioning the delivery system of the subject invention within the female vaginal tract and retaining the system a prolonged period of time within the vaginal tract. Thus the present invention concerns a delivery system and a method as described below in the independent claims.

DETAILED DESCRIPTION OF THE INVENTION

The advantages of the invention are obtained by the intravaginal delivery system comprising at least one compartment comprising a core and optionally a membrane encasing the core, said core and membrane essentially consisting of a same or different polymer composition, wherein at least one of said compartments comprises one or more therapeutically active or health-promoting substances capable of preventing and/or treating vaginal infections as well as giving the protection against bacterial and fungal infections and/or against sexually transmitted diseases.

According to an embodiment of the invention, the intravaginal delivery system comprises at least one compartment, said one or each compartment comprising a core and optionally a membrane encasing the core, said core and membrane essentially consisting of a same or different polymer composition, wherein at least one of the cores comprises one or more therapeutically active or health-promoting substances capable of preventing and/or treating vaginal infections as well as giving the protection against bacterial and fungal infections and/or against sexually transmitted diseases.

According to another embodiment of the invention, the intravaginal delivery system comprises at least one compartment, said one or each compartment comprising a core and a membrane encasing the core, said core and membrane essentially consisting of a same or different polymer composition, wherein the membrane comprises one or more therapeutically active or health-promoting substances capable of preventing and/or treating vaginal infections as well as giving the protection against bacterial and fungal infections and/or against sexually transmitted diseases.

According to a further embodiment of the invention, the intravaginal delivery system comprises at least one compartment, said one or each compartment comprising a core and optionally a membrane encasing the core, said core and membrane essentially consisting of a same or different polymer composition, wherein the surface of the membrane or the surface of at least one core comprises one or more therapeutically active or health-promoting substances capable of preventing and/or treating vaginal infections as well as giving the protection against bacterial and fungal infections and/or against sexually transmitted diseases.

Thus the therapeutically active or health-promoting substances may be within the core, the membrane or both, or on the surface of the core or of the membrane. Preferably, these substances are on the surface of the membrane or of the core. According to a preferred embodiment, the intravaginal delivery system according to the invention can be used for prevention and/or treatment of vaginal infections, e.g. bacterial vaginosis and (vulvo)vaginal candidiasis (vaginal yeast infections).

Any suitable design of the delivery system or any combination of structure is naturally possible and within the scope of the invention.

According to the embodiment in which the delivery system consists of two or more compartments, said compartments are preferably positioned next to each other. The compartments may also be side-by-side or one on the other, for example as described in US 4,822,616 and US 4,012,496 by Schering AG or in WO 95/00199 by Leiras Oy, a compartment being assembled on or encircling the surface of another compartment or assembled in a groove on the surface of another compartment. The length of the compartments may be same or different. The compartments may or may not be separated from each other by a separation membrane or by an inert placebo compartment.

The membrane may cover the whole delivery system or cover only a part of the system, whereby the degree of extension can vary depending on a number of factors, for example such as the choice of materials and the choice of the substances. The thickness of the membrane depends on materials and active agents used as well as on desired release profiles, but generally the thickness is smaller than the thickness of the core member.

The membrane may consist of more than one layer, in which case one of the layers or several layers may comprise a therapeutically active or a health-promoting substance capable of preventing and/or treating vaginal infections as well as giving the protection against bacterial and fungal infections and/or against sexually transmitted diseases. Each layer has a certain thickness, and the thickness of the layers may be the same or different. The outer surface or membrane may further have different designs, grooves or holes, in which case at least one of the grooves or holes may comprise a therapeutically active or a health-promoting substance capable of preventing and/or treating vaginal infections as well as giving the protection against bacterial and fungal infections and/or against sexually transmitted diseases. Each groove or hole may have certain dimensions. The combination of different membrane designs or material or both, gives a further possibility for controlling the release of said substances. The surface of at least one of the cores or of the membranes may also comprise a therapeutically active or a health- promoting substance in the form of granules, particles, crystals, microcrystals, powder, suspension or a like. The polymer composition used in the membrane is preferably such that it allows the pre-determined release rates of the substance.

Polymer compositions of the core, the membrane and the possible separation membrane or the inert placebo compartment, can be the same or different and may stand for one single polymer, a mixture of polymers or the polymer composition may be made up of polymers that are blended with each other.

In principle any polymer, either biodegradable or non-biodegradable, can be used as long as it is biocompatible.

Polysiloxanes, in particular poly(dimethyl siloxane) (PDMS), are highly suitable for use as a membrane or matrix material. Polysiloxanes are physiologically inert, and a wide group of drugs are capable of penetrating polysiloxane membranes, which also have the required strength properties. The permeation rate of the substances can be adjusted by modifying the polymeric material in a suitable way, e.g. by adjusting hydrophilic or hydrophobic properties of the material by addition of poly(ethylene oxide) groups or trifluoropropyl groups to a PDMS polymer.

Further examples of suitable materials include, but are not limited to, copolymers of dimethylsiloxanes and methylvinylsiloxanes, ethylene/vinyl acetate copolymers (EVA), polyethylene, polypropylene, ethylene/propylene copolymers, acrylic acid polymers, ethylene/ethyl acrylate copolymers, polytetrafluoroethylene (PTFE), polyurethanes, thermoplastic polyurethanes, polyurethane elastomers, polybutadiene, polyisoprene, poly(methacrylate), polymethyl methacrylate, styrene-butadiene-styrene block copolymers, poly(hydroxyethylmethacrylate) (pHEMA), polyvinyl chloride, polyvinyl acetate, polyethers, polyacrylonitriles, polyethylene glycols, polymethylpentene, polybutadiene, polyhydroxy alkanoates, poly(lactic acid), poly(glycolic acid), polyanhydrides, polyorthoesters, hydrophilic polymers such as the hydrophilic hydrogels, cross-linked polyvinyl alcohol, neoprene rubber, butyl rubber, hydroxyl- terminated organopolysiloxanes of the room temperature vulcanizing type which harden to elastomers at room temperature following the addition of cross-linking agents in the presence of curing catalysts, one- or two-component dimethylpolysiloxane compositions cured by hydrosilylation at room temperature or under elevated temperatures, as well as mixtures thereof.

Preferably the polymer composition(s) is /are selected from the group consisting of polydimethyl siloxanes, modified polydimethyl siloxanes, ethylene/vinyl acetate copolymers (EVA), polyethylene, polypropylene, acrylic acid polymers, polytetrafluoroethylene (PTFE), polyurethanes, thermoplastic polyurethanes, polyurethane elastomers, poly (methacrylate), polymethyl methacrylate, poly(hydroxyethylmethacrylate) (pHEMA), polyhydroxy alkanoates, polyQactic acid), poly(glycolic acid), hydrophilic polymers such as the hydrophilic hydrogels, cross-linked polyvinyl alcohol and combinations thereof.

The structural integrity of the material may be enhanced by the addition of a particulate material such as silica or diatomaceous earth. Other additives, which need to be biocompatible and harmless to the patient, for example complex forming agents such as cyclodextrin derivatives, tensides, anti-foaming agents, solubilisers or absorption retarders, or a mixture of any two or more of such substances, can also be added in order to impart the desired physical properties to the body of the delivery system. Further, additives such as pigments, glossing agents, matting agents, colorants, mica or equal can be added to the body of the delivery system or the membrane or to both in order to provide the delivery system with a desired visual appearance. According to an embodiment, the core and the membrane are made of a siloxane based elastomer composition comprising at least one elastomer and possibly a non- crosslinked polymer.

The term "elastomer composition" may stand for one single elastomer, the deformation of which caused by the strain is reversible so that the elastomer's shape recovers to a certain level after the strain. The elastomer composition may also be made up of two or more elastomers blended with each other.

When the therapeutically active or a health-promoting substance is relatively large molecule, such as for example Lactobacillus species, biodegradable polymers, for example hydrogels, are especially suitable membrane or matrix materials.

Term "health-promoting agent" means a health-sustaining agent or a health-enhancing agent or generally a substance or a combination of substances that are or may be used for the purpose of maintaining and/or improving health or treating and/or preventing disease conditions.

Therapeutically active substances include compounds which can be used to treat and/or prevent bacterial or fungal infections and/or sexually transmitted diseases, for example antimicrobial agents, antibacterial agents, antiviral agents, antibiotics, e.g. metronidazole, antifungal agents, anti-inflammatoric agents and the like.

According to the present invention the therapeutically active or health-promoting substance(s) is/are selected from the group consisting of lactic acid, polylactic acids, glycolic acid, polyglycolic acid, ascorbic acid, folic acid and the reduced forms thereof, especially tetrahydrofolates and metabolites of folic acid, preferably 5-methyl-6(S)- tetrahydrofolic acid and its salts, especially its earth alkaline salts, of these the calcium salt (Metafolin) being preferred, p-aminobenzoic acid, alginic acid, sorbic acid, tartaric acid, edetic acid, salts of these acids, niacinamide, Bifidobacterium strains, Lactobacillus species, for example such as Lactobacillus reuteri, Lactobacillus reuterii RC- 14, Lactobacillus delbrueckii, Lactobacillus gasseri, Lactobacillus jensenii, Lactobacillus catenaforme, Lactobacillus paracasei, Lactobacillus paracasei Lbp PBOl, Lactobacillus casei, Lactobacillus acidophilus, Lactobacillus acidophilus Lba EBOl, Lactobacillus acidophilus Lba EB02, Lactobacillus crispatus, Lactobacillus crispatus CTV05, Lactobacillus salivarius, Lactobacillus brevis, Lactobacillus fermentum, Lactobacillus fermentum RC- 14, Lactobacillus fermentum B-54, Lactobacillus plantarum, Lactobacillus plantarum Lbpl PB02, Lactobacillus Lbxx EB03, Lactobacillus Lbxx PB03, Lactobacillus rhamnosus Lactobacillus rhamnosus GR-I and other genus or strains of Lactobacillus with essentially the same properties. Preferably a combination of at least two Lactobacillus strains is used.

The delivery system may additionally contain a source (or sources) of substances known to support the optimal growth of lactobacilli to ensure fast, complete and sustained repopulation of the urogenital tract. These substances can be one or any combination of the following: 4-aminobenzoic acid, vitamin K, group B vitamins, e.g. Bl, B2, B6 and B 12, casein peptone, magnesium sulfate, ferrous sulphate, manganous sulphate, polysorbate and acetate. The composition can be buffered with e.g. potassium dihydrogen sulphate to improve the environment for growth.

The amount of the therapeutically active or health-promoting agent incorporated in the delivery system varies depending on the particular therapeutically active or health- promoting agent, intended use of the substance, expected release rate and the time for which the system is expected to provide therapy. Since a variety of devices with varying sizes can be formulated for administering dosages, there is no critical upper limit on the amount of agent incorporated in the device. The lower limit depends on the activity of the therapeutically active or health-promoting agent and the expected release time. A person skilled in the art is readily able to determine the amount of the therapeutically active agent needed for each specific application of the delivery system.

The amount of the therapeutically active or health promoting agent varies between almost zero to 20 wt-%, the preferred amount being between 1-20 wt-% of the weight of the intravaginal delivery system. Other possible ranges of the amount of the therapeutically active agent are 0.5-15 wt-%, 1-10 wt-%, 5-20 wt-%, 8-15 wt-%.

The daily dosage of the therapeutically active substances for a defined condition to be treated and for a defined substance can be achieved with the delivery system according to the invention particularly by selecting the optimal placement of the substance in the system, or by varying the polymer composition of the membrane. In addition to modifying the polymers, other parameters such as the size and form of the device, the drug load, etc. will influence the daily dose released from said device. Some, but not undue, experimentation will be needed to find the most suitable parameters for each combination.

Significantly lower dosages than needed for the systemic application are sufficient if released by the intravaginal route. For lactobacillus species no official requirement concerning the therapeutic cell counts for the urogenital application exists. In the vaginal applications the cell counts may vary from 10 -10 CFU/product, or even above.

Depending on the use of the device, the expected release time of therapeutically active agents or health-promoting agents may vary from one day up to 3 months, preferably from one day to 1 month and more preferably from one day to three weeks.

A preferred intravaginal delivery system according to the invention comprises at least one compartment, most preferably one compartment, comprising a core and optionally a membrane encasing the core, wherein the surface of the core, the membrane or the surface of the membrane comprises at least one therapeutically active or a health- promoting substance capable of preventing and/or treating vaginal infections as well as giving the protection against bacterial and fungal infections and/or against sexually transmitted diseases, said substance preferably being selected from the group of lactic acid, folic acid, reduced forms thereof, e.g. tetrahydrofolates, metabolites of folic acid, such as 5-methyl-6(S)-tetrahydrofolic acid and its salts, especially the calcium salt (Metafolin), strains of Lactobacillus, especially Lactobacillus reuteri, Lactobacillus reuterii RC-14, Lactobacillus gasseri, Lactobacillus paracasei, Lactobacillus paracasei Lbp PBOl, Lactobacillus acidophilus, Lactobacillus acidophilus Lba EBOl, Lactobacillus acidophilus Lba EB 02, Lactobacillus crispatus CTV05, Lactobacillus fermentum RC-14, Lactobacillus fermentum B-54, Lactobacillus plantarum,

Lactobacillus plantarum Lbpl PB 02, Lactobacillus Lbxx EB 03, Lactobacillus Lbxx PB 03, Lactobacillus rhamnosus Lactobacillus rhamnosus GR-I, or a combination of at least two thereof.

The intravaginal drug delivery system presented herein can especially be used for prevention and/or treatment of vaginal infections, e.g. bacterial vaginosis and (vulvo)vaginal candidiasis (vaginal yeast infections). A slow release of the substance, for example a Lactobacillus strain, is accomplished after introduction of the delivery system at the end of menses. Thus it will offer the most favourable time for using such health-promoting substances and optimal therapeutic effect. Further, cyclic use of these substances in this way would be most beneficial and best clinical practice.

The present invention further concerns a method of preventing and/or treating vaginal infections as well as giving the protection against bacterial and fungal infections and/or against sexually transmitted diseases by using an intravaginal delivery system, said method comprising the steps of positioning the delivery system within the female vaginal tract and retaining the system for a prolonged period of time within the vaginal tract, preferably from one day to three weeks wherein said delivery system releases a sufficient amount of a substance capable of preventing and/or treating vaginal infections as well as giving the protection against bacterial and fungal infections and/or against sexually transmitted diseases.

Manufacture of the device

The delivery system according to this invention can be manufactured by any known techniques. The therapeutically active or health-promoting substance may be mixed within the core or membrane material, whereafter the material is processed to the desired shape by moulding, injection moulding, rotation/injection moulding, casting, extrusion, such as co-extrusion, coating extrusion and/or blend-extrusion or other appropriate methods. The membrane layer can be applied onto the core according to known methods, such as by mechanical stretching or expanding a prefabricated, tube formed membrane by pressurised gas, e.g. by air, swelling in a suitable solvent, for example such as cyclohexane, diglyme, propanol, isopropanol or a mixture of solvents, or by extrusion, moulding, spraying or dipping. The ends of the extruded core or cores or the core- membrane rod can be joined together to form a drug delivery device using a coupling means, which can be any method, mechanism, device or material known in the art for bonding or joining materials or structures together. The surface of a core and / or a membrane can be encased, coated, dusted or smoothed by granules, particles, crystals, microcrystals, powder or suspension of a therapeutically active or a health- promoting substance by using known methods, for example by spraying the whole delivery system or a part of it, i.e. a core or a compartment, with a suspension of said substance in a suitable solvent or by dipping the system in such a suspension. Therapeutically active or health-promoting substances can also be mixed or suspended in a carrier material known in the art, for example silicone oil or hard fat or other encapsulation material, which is then applied on the surface of the core or the membrane or in a groove or hole on the surface of the core or membrane, and finally, if needed, covered by an additional outer membrane.

The device can have many shapes, for example various continuous, curved shapes, such as annular, ring-shaped, oval, spiral, ellipse, toroidal and the like. The cross section of the device can have almost any shape, and it can be for example circular, oval, flat, ellipse, star-shaped and the like.

The delivery system can also comprise a substantially inert supporting means made of a material which is biologically compatible and remains unchanged for a sufficient period of time in the conditions prevailing in the vagina. The term "substantially inert" means in this connection that the active agent cannot, to any substantial degree, diffuse or in any other way migrate from the core into the support means. Suitable supporting materials are for example cross-linked rubbers, such as e.g. natural rubber, butyl rubber and polydimethylsiloxane elastomers, flexible thermoplastic resins, such as ethyl vinyl acetate (EVA), thermoplastic polymers, such as styrene copolymers, polyurethanes, thermoplastic polyolefins and inert, biocompatible metals.

One or more cores or membranes may be assembled on the prefabricated closed, continuous supporting member in the form of layers or coatings, for example by applying the polymer composition as such, or the polymer composition comprising the finely ground or even micronized active substance, as a layer on the supporting means by using known techniques, such as spraying, dipping or the multi-colour injection moulding technique, and vulcanized by known methods.

The delivery system according to the invention can be manufactured in any size as required, the exact size is being dependent on the mammal and particular application. In practice, for a human female an outer ring diameter is typically from 35 to 70 mm, preferably from 35 to 58 mm or from 45 to 65 mm and more preferably from 50 to 58 mm. The cross sectional diameter is typically from 1 to 10 mm. In a particular embodiment the cross sectional diameter is between 2 and 6 mm, in a specific embodiment between about 3.0 and 5.5 mm and in another embodiment between about 3.5 and 4.5 mm and in yet another embodiment is between 4.0 and 5.0 mm.

The length of the compartments can be for example from 3 to 160 mm, or up to the total length of the delivery system.

The thickness of the membrane is from 0.1 to 1.0 mm, preferably 0.2 to 0.6 mm.

EXAMPLES

The invention is further illustrated by the following, non-limiting examples. The delivery systems of the examples are manufactured in accordance with standard techniques known in the art and described in the patent application. The therapeutically active or the health promoting substance(s) may be mixed within the polymer composition of the core or the membrane, and processed to the desired shape. The surface of the core or the membrane of prefabricated polymer compartments may be coated by said substance(s) by using known methods. Therapeutically active or health- promoting substances can for example be incorporated in a carrier material to form a suspension, which is then applied as a layer on the core or the membrane by using known techniques, such as spraying, dipping or the multi-colour injection moulding technique. The membrane is made and assembled onto the cores according to known methods, such as by expanding the prefabricated, tube formed membrane in a suitable solvent, for example such as propanol, isopropanol, or by using coating extrusion or a coextrusion method described in the Finnish patent FI 97947 ^'. According to said method, each of the cores are fed to the extruder followed either by an empty space filled with air or by another core without any active ingredient. The ends of the fabricated rods comprising the cores and the membrane are joined together by using a plug or a sealant. Silica is preferably used as a filler.

Example 1 A delivery system for the administration of folic acid

The core comprises PEO-b-PDMS copolymer (25 wt-% of the total amount of polymers) and PDMS, the length of the core is 165 mm and the outer diameter is 3.0 mm. The membrane comprising 4 wt-% of folic acid is made of PEO-b-PDMS copolymer (15 wt-%) and PDMS (85 wt-%). The wall of the membrane tube is 0.25 mm, inner diameter 2.85-2.9 mm and the outer diameter 3.35-3.4 mm. The core and the tube-formed membrane are made by extrusion. The core is coated by the membrane by first swelling the membrane in propanol. The ends of the delivery system are joined into a ring by using a polyethylene plug. Example 2

A delivery system for the administration of Lactobacillus

The core comprises PEO-b-PDMS (34 wt-% of the total amount of polymers), PDMS and silica, the length of the core is 160 mm and the outer diameter of the core is 2.6-2.7 mm. The core is encased in a membrane consisting of PEO-b-PDMS/PDMS in a ratio of 10:90. The thickness of the membrane wall is 0.32 mm, inner diameter of the tube is 2.35 mm and the outer diameter approximately 3 mm. The ends of the delivery system are joined together with silicon glue to form a closed ring-like system. The outer surface of the membrane is coated with a thin layer of Lactobacillus acidophilus.

Example 3

A delivery system for the administration of a combination of Lactobacillus strains

The core comprises PEO-b-PDMS (34 wt-% of the total polymer amount), PDMS (34 wt-% of the total polymer amount) and silica, and the length of the core is 170 mm. The outer diameter of the core is 4.9 mm. The ends of the core are joined together into a closed delivery system by using an adhesive. The delivery system is coated with a mixture of Lactobacillus gasseri and Lactobacillus rhamnosus GR-I granulates suspended in a hard fat (Witepsol®) to give a thin coating.

Example 4

A delivery system for the administration of Lactobacillus

The core comprising PEO-b-PDMS (36 wt-% of the total polymer amount), PDMS (30 wt-% of the total polymer amount) and silica and having the length of 160 mm is encased in a membrane consisting of PEO-b-PDMS/PDMS in a ratio of 55:45. The thickness of the membrane wall is 0.45 mm. The outer diameter of the membrane encased core is 4.9 mm. The ends of the membrane-core system are joined together into a closed delivery system by using a silicone adhesive. The granulate of Lactobacillus reuterii RC-14 suspended in a hard fat (Witepsol®); 20 mg of suspension, 10 wt-% of which comprises the mixture of freeze dried Lactobacillus and excipients, e.g. lyoprotectants) is mechanically attached to groove in the surface of the delivery system. The release rate for Lactobacillus is 10 CFU.

Although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art can in the light of this teaching generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed invention. Accordingly, it is to be understood that the descriptions herein are offered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof.

Claims

1. An intravaginal delivery system comprising at least one compartment, said one or each compartment comprising a core and optionally a membrane encasing the core, said core and membrane consisting essentially of a same or different polymer composition, wherein the delivery system comprises at least one substance capable of preventing and/or treating vaginal infections as well as giving the protection against bacterial and fungal infections and/or against sexually transmitted diseases and said substance(s) is/are selected from the group consisting of lactic acid, polylactic acid, glycolic acid, polyglycolic acid, ascorbic acid, folic acid and the reduced forms thereof, p-aminobenzoic acid, alginic acid, sorbic acid, tartaric acid, edetic acid and salts of the acids, niacinamide, Bifidobacterium strains, and Lactobacillus species.

2. The intravaginal delivery system according to claim 1, wherein said reduced form of the folic acid is selected from the group consisting of tetrahydrofolates and metabolites of folic acid, preferably 5-methyl 6-(S)-tetrahydrofolic acid and its salts such as earth alkaline salts, especially the calcium salt (Metafolin).

3. The intravaginal delivery system according to claim 1 or 2, wherein said

Lactobacillus species is selected from the group consisting of Lactobacillus reuteri, Lactobacillus reuterii RC- 14, Lactobacillus delbrueckii, Lactobacillus gasseri, Lactobacillus jensenii, Lactobacillus catenaforme, Lactobacillus paracasei, Lactobacillus paracasei Lbp PBOl, Lactobacillus casei, Lactobacillus acidophilus, Lactobacillus acidophilus Lba EBOl, Lactobacillus acidophilus Lba EB02,

Lactobacillus crispatus, Lactobacillus crispatus CTV05, Lactobacillus salivarius, Lactobacillus brevis, Lactobacillus fermentum, Lactobacillus fermentum RC- 14, Lactobacillus fermentum B -54, Lactobacillus plantarum, Lactobacillus plantarum Lbpl PB 02, Lactobacillus Lbxx EB 03, Lactobacillus Lbxx PB 03, Lactobacillus rhamnosus, Lactobacillus rhamnosus GR-I, and other genus or strains of

Lactobacillus with essentially the same properties

4. The intravaginal delivery system according to claim 1 or 3, wherein said at least one substance is a combination of at least two Lactobacillus strains.

5. The intravaginal delivery system according to any of the preceding claims, wherein said at least one substance is in the core.

6. The intravaginal delivery system according to any of the claims 1 - 4, wherein said at least one substance is in the membrane.

7. The intravaginal delivery system according to any of the claims 1 - 4, wherein said at least one substance is on the surface of the core or of the membrane.

8. The intravaginal delivery system according to any of the claims 1-7, wherein said polymer composition(s) is/are selected from the group consisting of polydimethyl siloxanes, modified polydimethyl siloxanes, ethylene/vinyl acetate copolymers (EVA), polyethylene, polypropylene, acrylic acid polymers, polytetrafluoroethylene (PTFE), polyurethanes, thermoplastic polyurethanes, polyurethane elastomers, poly(methacrylate), polymethyl methacrylate, poly(hydroxyethylmethacrylate) (pHEMA), polyhydroxy alkanoates, polyQactic acid), poly(glycolic acid), hydrophilic polymers such as the hydrophilic hydrogels, cross-linked polyvinyl alcohol and combinations thereof.

9. A method of preventing and/or treating vaginal infections as well as giving the protection against bacterial and fungal infections and/or against sexually transmitted diseases by using an intravaginal delivery system, said method comprising the steps of positioning the delivery system within the female vaginal tract and retaining the system for a prolonged period of time within the vaginal tract, preferably from one day to three weeks wherein said delivery system releases a sufficient amount of a substance capable of preventing and/or treating vaginal infections as well as giving the protection against bacterial and fungal infections and/or against sexually transmitted diseases.