Vaginal contraceptive composition for enhancing mucus barrier properties

Abstract

The present disclosure relates to vaginal contraceptive compositions, which comprise one or more active ingredients and a physiologically acceptable gelling agent, wherein at least one of the one or more active ingredients is a mucoadhesive polymer, wherein the mucoadhesive polymer has a molecular weight between 20,000 Da and 100,000 Da, wherein the mucoadhesive polymer is composed of a plurality of monomer units connected to each other by ether bonds, ester bonds, amide bonds or combinations thereof, wherein the monomer units are selected from C6 sugars, amino-functionalized C6 sugars, amino acids or combinations thereof, and wherein at least 50% of the monomer units contain at least one amino group. The present disclosure also relates to the use of vaginal contraceptive compositions, vaginal contraceptive compositions for therapy, vaginal contraceptive compositions for use as contraceptives or contraceptive agents, and vaginal contraceptive compositions for fertility control or fertility control therapy.

Description

Technical Field

[0001] The present invention relates to a vaginal contraceptive composition comprising one or more active ingredients and a physiologically acceptable gelling agent, wherein at least one of the one or more active ingredients is a mucoadhesive polymer. The present invention also relates to the use of such a vaginal contraceptive composition in therapy or contraception. The mucoadhesive polymer can crosslink the mucus layer without causing mucus aggregation. Background Art

[0002] Patent documents are herein incorporated by reference solely for convenience and do not reflect any opinion as to the validity, patentability, and / or enforceability of these patent documents.

[0003] The number of women who dislike hormonal contraceptives but cannot obtain convenient (non-implantable, easy to use, flexible to use) and effective (greater than 90% efficacy in typical use) alternatives is increasing rapidly. Indeed, 125 million couples in Europe and the United States use birth control, and hormonal contraceptives (pills, patches, implants, rings, etc.) are by far the most commonly used birth control methods. However, the increasing awareness of the side effects caused by hormones has led to a disruption of the contraceptive market. Currently, there is clear evidence of the side effects of hormonal contraceptives. Three studies involving 500,000 to 1.8 million women showed that the use of hormonal contraceptives increased the rate of women taking antidepressants by 23%, and for adolescents, this rate was nearly doubled (Charlotte Wessel Skovlund, Lina Steinrud Lars Vedel Kessing, and Lidegaard. 2016. “Association of Hormonal Contraception With Depression.” JAMA Psychiatry 73(11):1154–62), increased the rate of women's suicide attempts by 197% and the suicide rate by 308% (Charlotte Wessel Skovlund, Lina Steinrud Lars Vedel Kessing, Theis Lange, and Lidegaard. 2017. “Association of Hormonal Contraception With Suicide Attempts and Suicides.” The American Journal of Psychiatry, (November) and when used for less than 1 year, increased the risk of breast cancer by 9%, and when used for 10 years, increased it by up to 38% (Lina S.) Charlotte W. Skovlund, Philip C. Hannaford, Lisa Iversen, Shona Fielding, and Lidegaard. 2017. “Contemporary Hormonal Contraception and the Risk of Breast Cancer.” The New England Journal of Medicine 377(23):2228–39). Many women currently wish to stay away from hormonal contraception, but they have not been able to find a suitable alternative. Current alternatives are inconvenient (condoms, diaphragms) or traumatic (copper and hormonal eluting implants), and can be less effective in actual use situations (for example, condoms are only 85% effective on average).

[0004] There are more than 400 square meters of epithelial surfaces hidden in the human body, including the lungs, gastrointestinal tract, and female genital tract. The wet epithelial surfaces rely on mucus gels to protect against dehydration, shear stress, and infection. Besides water, mucus mainly contains mucin biopolymers mixed with proteins, lipids, and salts. Mucins are large glycoproteins that consist of an extended central protein core densely conjugated with oligosaccharides, which can account for up to 50% of the molecular weight of the molecule. The main role of mucins is a protective function, which creates a barrier that serves as a size exclusion and affinity-based selective filter to prevent various harmful molecules from reaching the epithelial surface.

[0005] Due to their adhesiveness, mucoadhesive polymers have been used in drug delivery. For example, they have been used to deliver drugs to the site of inflammation.

[0006] Mucoadhesive polymers are usually assembled with drugs into materials or gels with the aim of concentrating the drugs on the surface of the mucus layer and improving drug delivery.

[0007] WO2004069230 relates to a pharmaceutical composition that contains a physiologically active agent, namely a drug, and a sustained release agent or a mucoadhesive agent, such as chitosan, for prolonging the release of the agent from the composition.

[0008] Other uses of chitosan lie in female contraception. An example of this can be seen in CN102895256, which relates to a chitosan gel foam suitable for female contraception and fungicidal action and its preparation method, and belongs to the technical field of foam production. According to the disclosure of the present invention, chitosan molecules and polyacrylic acid are entrapped together in a solid foam matrix, which physically prevents sperm from passing through. Additionally, the chitosan has a molecular weight distribution of 2000 - 5000 Da, a degree of deacetylation greater than 95%, and a concentration of 5 - 10 wt.%, while the polyacrylic acid is at a concentration of 1 - 3 wt.%.

[0009] Another example of chitosan for female contraception can be seen in WO2018185321, which relates to a mucoadhesive polymer, more specifically chitosan, which can crosslink the mucus layer without mucus aggregation. The chitosan consists of 4 to 20 monomer units and has a degree of deacetylation greater than 50%.

[0010] A third example can be seen in US4474769, which relates to a method of directly injecting a chitosan preparation into the female uterine cavity for an extended period of time to kill mammalian sperm or inactivate mammalian sperm.

[0011] It is known that mucoadhesive molecules promote the tightness and thickening of mucosal tissues or enhance the barrier function, but the use of mucoadhesive polymers and mucus-penetrating nanoparticles will crosslink and aggregate the mucus, resulting in the formation of a highly swollen interpenetrating polymer network. Therefore, mucus aggregation causes the pores within the mucus to open and weakens the mucus barrier. Thus, there is still a need in the field of compositions that show improved mucus crosslinking without aggregation.

[0012] Therefore, the objective of the present invention is to provide a mucoadhesive polymer that can crosslink the mucus layer at the female cervical entrance, i.e., the mucus layer of the outer cervix, without causing mucus aggregation or with a lower degree of aggregation compared to previous compositions in the art. The outer cervix is the protective mucosa on the outside of the cervix. Preferably, the mucoadhesive polymer can also crosslink the mucus layer at the female cervical entrance at the inner cervix (which is the mucosa of the cervical canal). The crosslinking should be sufficient to prevent motile sperm from moving through the mucus layer.

[0013] Another objective of the present invention is to provide a mucoadhesive polymer that provides a more reliable barrier effect for preventing cells and microorganisms, such as bacteria, viruses, and / or sperm, from penetrating the crosslinked mucus and diffusing into the mucosa.

[0014] Another objective of the present invention is to provide a mucoadhesive polymer that provides a sufficient barrier effect for preventing pregnancy and / or sexually transmitted infections (STIs). SUMMARY OF THE INVENTION

[0015] Newly developed techniques are disclosed herein that provide a non-invasive, user-friendly, and effective alternative to hormonal contraception. The strategy relies on making the cervical mucus (the body's natural barrier between the vagina and the uterus) temporarily impermeable to sperm cells. Cervical mucus protects women from infection and is generally impermeable to foreign cells throughout the month. However, around the time of ovulation, hormonal changes loosen the mucus, which then becomes highly permeable to sperm cells. It has been found that the delivery of a mucoadhesive (bio)polymer to the cervical mucus can alter the microstructure of the mucus gel and thereby enhance the body's own natural barrier and prevent fertilization.

[0016] Previously, low molecular weight mucoadhesive polymers containing 4 to 20 monomers (see, for example, WO2018185321 or Biomacromolecules, 2018, 19, 3, 872 - 882) have been identified as ideal mucoadhesive polymers for enhancing the mucus barrier by crosslinking the mucus. It is thought that the small size of the polymer will advantageously allow the molecule to diffuse into the interior of the mucus. This should improve the diffusion of the mucoadhesive polymer into the mucosa, allowing it to crosslink the mucus layer at a large thickness without causing mucus aggregation. The small mucoadhesive polymer complex will thereby block the pores of the network and enhance the barrier. However, it has been shown that in porcine gastric mucin and colonic mucin cell lines, the enhancement of this barrier by (for example) chitosan works for small chitosan sizes, but for applications as a contraceptive composition, the targeted mucus differs greatly from the mucins in the gastrointestinal tract. During ovulation, the cervical mucus loosens, allowing sperm to pass through the gel. Compared to gastric or colonic mucus, the mucin content is reduced and the general mucus structure and composition are quite different. Therefore, it is very important that the mucus layer is crosslinked sufficiently to prevent motile sperm from moving through the mucus layer without mucus aggregation.

[0017] Mucus aggregation occurs when mucin polymers condense around the mucoadhesive polymer. As a result, very dense regions of mucin polymer aggregates are produced and very open and very loose mucin network regions are produced. These open regions can allow sperm to pass through.

[0018] Accordingly, the present invention relates to a vaginal contraceptive composition comprising one or more active ingredients and a physiologically acceptable gelling agent, wherein at least one of the one or more active ingredients is a mucoadhesive polymer, wherein the mucoadhesive polymer has a molecular weight between 20,000 Da and 100,000 Da, wherein the mucoadhesive polymer is composed of a plurality of monomer units connected to each other by ether bonds, ester bonds, amide bonds or combinations thereof, wherein the monomer units are selected from C6 sugars, amino-functionalized C6 sugars, amino acids or combinations thereof, and wherein at least 50% of the monomer units contain at least one amino group.

[0019] As shown herein, in fact, mucoadhesive polymers of 4 and 20 monomers as discussed above are not suitable for effectively enhancing the mucus barrier in ovulatory mucus for the treatment of gastric and colonic mucus. It has been shown that mucoadhesive polymers of at least 20,000 Da are more effective in forming a barrier against sperm cells that seek to penetrate the mucus barrier. Additionally, it is shown herein that mucoadhesive polymers greater than 100,000 Da are too large and have poor interaction with mucus.

[0020] If formulated in a vaginal gel, the composition as disclosed herein can be effectively delivered to the cervix. The composition of the gel can prevent the mucoadhesive polymer from diffusing from the gel into the mucus either by steric hindrance effects or by intermolecular interactions with the mucoadhesive polymer and molecules forming aggregates in the gel. For example, if the mucoadhesive polymer is provided as a soft gel based on a carboxymethylcellulose (CMC) excipient, which is commonly used as a gelling agent, this component will interact strongly with, for example, chitosan if used as the mucoadhesive polymer. At least two different types of gelling agents are suitable for vaginal formulations, neutral and positively charged, and do not prevent the penetration of the mucoadhesive polymer into cervical mucus during the female ovulatory period and do not impair the barrier-enhancing effect obtained through the mucoadhesive polymer. The gelling agent needs to be neutral or positively charged to avoid strong interaction with the mucoadhesive polymer. That is, another example is that if the mucoadhesive polymer interacts with mucus through thiol groups, the excipient should not contain thiol groups.

[0021] The present invention also relates to the use of a vaginal contraceptive composition as a contraceptive agent, wherein the vaginal contraceptive composition comprises one or more active ingredients and a physiologically acceptable gelling agent, wherein at least one of the one or more active ingredients is a mucoadhesive polymer, wherein the mucoadhesive polymer has a molecular weight between 20,000 Da and 100,000 Da, wherein the mucoadhesive polymer is composed of a plurality of monomer units connected to each other by ether bonds, ester bonds, amide bonds or combinations thereof, wherein the monomer units are selected from C6 sugars, amino-functionalized C6 sugars, amino acids or combinations thereof, and wherein at least 50% of the monomer units contain at least one amino group.

[0022] The present invention also relates to a vaginal contraceptive composition for use in therapy, wherein the vaginal contraceptive composition comprises one or more active ingredients and a physiologically acceptable gelling agent, wherein at least one of the one or more active ingredients is a mucoadhesive polymer, wherein the mucoadhesive polymer has a molecular weight between 20,000 Da and 100,000 Da, wherein the mucoadhesive polymer is composed of a plurality of monomer units connected to each other by ether bonds, ester bonds, amide bonds or combinations thereof, wherein the monomer units are selected from C6 sugars, amino-functionalized C6 sugars, amino acids or combinations thereof, and wherein at least 50% of the monomer units contain at least one amino group.

[0023] Furthermore, the present invention relates to a vaginal contraceptive composition for use as a contraceptive or contraceptive agent, wherein the vaginal contraceptive composition comprises one or more active ingredients and a physiologically acceptable gelling agent, wherein at least one of the one or more active ingredients is a mucoadhesive polymer, wherein the mucoadhesive polymer has a molecular weight between 20,000 Da and 100,000 Da, wherein the mucoadhesive polymer is composed of a plurality of monomer units connected to each other by ether bonds, ester bonds, amide bonds or combinations thereof, wherein the monomer units are selected from C6 sugars, amino-functionalized C6 sugars, amino acids or combinations thereof, and wherein at least 50% of the monomer units contain at least one amino group.

[0024] The present invention also relates to a vaginal contraceptive composition for use in fertility control or fertility control therapy, wherein the vaginal contraceptive composition comprises one or more active ingredients and a physiologically acceptable gelling agent, wherein at least one of the one or more active ingredients is a mucoadhesive polymer, wherein the mucoadhesive polymer has a molecular weight between 20,000 Da and 100,000 Da, wherein the mucoadhesive polymer is composed of a plurality of monomer units connected to each other by ether bonds, ester bonds, amide bonds or combinations thereof, wherein the monomer units are selected from C6 sugars, amino-functionalized C6 sugars, amino acids or combinations thereof, and wherein at least 50% of the monomer units contain at least one amino group.

[0025] Finally, the present invention relates to methods of treatment, methods of avoiding pregnancy, contraceptive methods, and / or methods of fertility control or fertility control therapies, wherein the methods comprise the step of using a vaginal contraceptive composition comprising one or more active ingredients and a physiologically acceptable gelling agent, wherein at least one of the one or more active ingredients is a mucoadhesive polymer, wherein the mucoadhesive polymer has a molecular weight between 20,000 Da and 100,000 Da, wherein the mucoadhesive polymer is composed of a plurality of monomer units connected to each other by ether bonds, ester bonds, amide bonds, or combinations thereof, wherein the monomer units are selected from C6 sugars, amino-functionalized C6 sugars, amino acids, or combinations thereof, and wherein at least 50% of the monomer units comprise at least one amino group. Description of the Drawings

[0026] Figures 1A - 1I —Diffusion of chitosan into cervical, ovulatory mucus: 0.5% CS / / pH 5.5

[0027] Figure 1A , Figure 1B , Figure 1C —The left figure is the diffusion curve of chitosan in CVM at an exposure time of 20 ms, expressed as the chitosan concentration (% w / v), and the chitosan is from the shells of crustaceans with various molecular weights. The right figure is the diffusion curve of chitosan in CVM expressed as the relative fluorescence intensity (RFI) of labeled chitosan measured by microscopy at an exposure time of 800 ms, and the chitosan is from the shells of crustaceans with various molecular weights. The decrease in fluorescence marks the maximum diffusion distance after 30 minutes of exposure to mucus. All samples were dissolved in 32.5 mM LAC.

[0028] Figure 1D , Figure 1E , Figure 1F , Figure 1G , Figure 1H —The left figure is the diffusion curve of chitosan in CVM at an exposure time of 20 ms, expressed as the chitosan concentration (% w / v), and the chitosan is of non-animal origin with various molecular weights. The right figure is the diffusion curve of chitosan in CVM expressed as the relative fluorescence intensity (RFI) of labeled chitosan measured by microscopy at an exposure time of 800 ms, and the chitosan is of non-animal origin with various molecular weights. The decrease in fluorescence marks the maximum diffusion distance after 30 minutes of exposure to mucus. The samples were dissolved in 32.5 mM LAC.

[0029] Figure 1I —Representative images of chitosan permeation tests performed using chitosans of different sizes. Intensity curves were measured for these images to generate Figures 1A - 1C plots.

[0030] Figure 2 —Quantification of chitosan accumulation in human cervical ovulatory mucus after 30 min exposure as a function of chitosan molar mass.

[0031] Figures 3A - 3C —Sperm penetration through cervical ovulatory mucus: 0.5% (w / v) CO chitosan, in solutions of only water (H 2 O) at pH 5.5 ( Figure 3A ), phosphate buffered saline (PBS) ( Figure 3B ), or 100 mM lactic acid (LAC) ( Figure 3C ).

[0032] Figures 4A - 4E —Sperm penetration through human cervical ovulatory mucus ( Figure 4A —7.1 kDa, Figure 4B - 18.9 kDa, Figure 4C - 2 7.9 kDa, Figure 4D - 36.2 kDa, and Figure 4E - 2 51.8 kDa). The mucus was untreated (w / o), treated with 32.5 mM lactic acid solution (LAC) (for Figure 4A —100 mM lactic acid solution for 7.1 kDa) or treated with fungal-based chitosan dissolved in 32.5 mM lactic acid solution (for Figure 4A —100 mM lactic acid solution for 7.1 kDa). The molar mass of the chitosan used is labeled on the left side of the figure.

[0033] Figures 5A - 5D —Sperm penetration through human cervical ovulatory mucus ( Figure 5A —1.4 kDa, Figure 5B - 35.0 kDa, Figure 5C - 1.4 kDa + 35.0 kDa, and Figure 5D - 150.0 kDa). The mucus was untreated (w / o), treated with 100 mM lactic acid solution (LAC) or treated with chitosan based on crustacean shells dissolved in 100 mM lactic acid solution. The molar mass of the chitosan used is labeled on the left side of the figure.

[0034] Figure 6 —Solubility test of chitosan in a formulation containing a thickening agent as an excipient. Transmittance (%T) or turbidity (at 600 nm) was measured for lactic acid solution (32.5 mM, LAC) and solutions of hydroxyethyl cellulose (HEC) in LAC. The molar mass of the chitosan used corresponded to the following: Z10—36.2 kDa, 95 / 5 - 35 kDa, and CO - 1.4 kDa.

[0035] Figures 7A - 7C — Diffusion of chitosan into ovulatory cervical mucus: 0.5% CS ∥ pH 5.5( Figure 7A — 35.0 kDa w / o, Figure 7B - 35.0 kDa + 2.7% HEC and Figure 7C - 35.0 kDa + 1.6% HEC + 2.5% glycerol). After 30 min of exposure, for chitosan alone and chitosan blended with excipients, the concentration of chitosan in ovulatory cervical mucus at 20 ms (%, w / v). Samples were dissolved in 32.5 mM LAC. The relative fluorescence intensity (RFI) was measured through a microscope with an exposure time of 800 ms. Samples were dissolved in 32.5 mM LAC. The molar mass of the chitosan used was labeled above each figure.

[0036] Figures 8A - 8C — Sperm penetration through human cervical ovulatory mucus. The mucus was untreated (w / o), treated with 32.5 mM lactic acid solution (LAC) or with chitosan (95 / 5) based on crustacean shells with a molar mass of 35 kDa dissolved in 32.5 mM lactic acid solution ( Figure 8A ), 32.5 mM lactic acid and 2.7% hydroxyethyl cellulose (HEC)( Figure 8B ) or 32.5 mM lactic acid, 2.7% hydroxyethyl cellulose and 2.5% glycerol (Gro)( Figure 8C ).

[0037] Figures 9A - 9B — Sperm penetration through human cervical ovulatory mucus of poly-L-lysine (PLL)( Figure 9A — 1.6 kDa, Figure 9B — 66 kDa). The mucus was untreated (w / o), treated with 32.5 mM lactic acid solution (LAC) or with low molar mass poly-L-lysine dissolved in 32.5 mM lactic acid solution at a concentration of 5 mg / mL( Figure 9A ) or with high molar mass poly-L-lysine dissolved in 32.5 mM lactic acid solution at a concentration of 5 mg / mL( Figure 9B ). Detailed Description of the Invention

[0038] Unless otherwise stated or clearly inconsistent with the context, in this document, for any aspect or embodiment of the present invention, the description of using terms such as "comprising", "having", "including" or "containing" for one or more elements is intended to provide support for similar aspects or embodiments of the present invention "consisting of", "consisting essentially of" or "essentially comprising" the specific one or more elements. For example, unless otherwise stated or clearly inconsistent with the context, a composition described herein as comprising a specific element should be understood to also describe a composition consisting of that element. It will also be understood that when used in this specification, the terms "comprising", "comprises", "including" and / or "includes" indicate the presence of the stated features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0039] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be understood to have a meaning consistent with their meaning in the context of the relevant art and will not be understood in an idealized or overly formal sense unless expressly so defined in the specification of this invention.

[0040] As used herein, unless the context clearly dictates otherwise, the singular forms "a", "an" and "the" are intended to include the plural forms, including "at least one". "At least one" should not be construed as limiting "one" or "a".

[0041] Unless otherwise claimed, the use of any and all examples or exemplary language (e.g., "such as") provided herein is merely intended to better describe the present invention and does not impose a limitation on the scope of the present invention. No language in this specification should be construed as indicating that any unclaimed element is essential to the practice of the present invention.

[0042] When describing the following embodiments, aspects and definitions, the present invention contemplates all the disclosed embodiments and definitions in combination with all the disclosed aspects. Additionally, all possible combinations and permutations of the embodiments are not explicitly described. Nevertheless, the mere fact that certain measures are recited in mutually distinct dependent claims or described in different embodiments does not mean that combinations of these measures may not be advantageously used. The present invention contemplates all possible combinations and permutations of the described embodiments.

[0043] In a first aspect of the present invention, there is disclosed a vaginal contraceptive composition comprising one or more active ingredients and a physiologically acceptable gelling agent, wherein at least one of the one or more active ingredients is a mucoadhesive polymer, wherein the mucoadhesive polymer has a molecular weight between 20,000 Da and 100,000 Da, wherein the mucoadhesive polymer is composed of a plurality of monomer units connected to each other by ether bonds, ester bonds, amide bonds or combinations thereof, wherein the monomer units are selected from C6 sugars, amino-functionalized C6 sugars, amino acids or combinations thereof, and wherein at least 50% of the monomer units contain at least one amino group.

[0044] In a second aspect of the present invention, there is disclosed the use of a vaginal contraceptive composition as a contraceptive agent, wherein the vaginal contraceptive composition comprises one or more active ingredients and a physiologically acceptable gelling agent, wherein at least one of the one or more active ingredients is a mucoadhesive polymer, wherein the mucoadhesive polymer has a molecular weight between 20,000 Da and 100,000 Da, wherein the mucoadhesive polymer is composed of a plurality of monomer units connected to each other by ether bonds, ester bonds, amide bonds or combinations thereof, wherein the monomer units are selected from C6 sugars, amino-functionalized C6 sugars, amino acids or combinations thereof, and wherein at least 50% of the monomer units contain at least one amino group.

[0045] In a third, fourth and fifth aspect of the present invention, there is disclosed a vaginal contraceptive composition for use in therapy, as a contraceptive or contraceptive agent and for use in fertility control or fertility control therapy, wherein the vaginal contraceptive composition comprises one or more active ingredients and a physiologically acceptable gelling agent, wherein at least one of the one or more active ingredients is a mucoadhesive polymer, wherein the mucoadhesive polymer has a molecular weight between 20,000 Da and 100,000 Da, wherein the mucoadhesive polymer is composed of a plurality of monomer units connected to each other by ether bonds, ester bonds, amide bonds or combinations thereof, wherein the monomer units are selected from C6 sugars, amino-functionalized C6 sugars, amino acids or combinations thereof, and wherein at least 50% of the monomer units contain at least one amino group.

[0046] In the sixth, seventh, eighth, and ninth aspects of the present invention, there are disclosed methods of therapy, methods of contraception, methods of birth control, and methods of fertility control or fertility control therapies, wherein the methods comprise the step of using a vaginal contraceptive composition, the vaginal contraceptive composition comprising one or more active ingredients and a physiologically acceptable gelling agent, wherein at least one of the one or more active ingredients is a mucoadhesive polymer, wherein the mucoadhesive polymer has a molecular weight between 20,000 Da and 100,000 Da, wherein the mucoadhesive polymer is composed of a plurality of monomer units connected to each other by ether bonds, ester bonds, amide bonds, or combinations thereof, wherein the monomer units are selected from C6 sugars, amino-functionalized C6 sugars, amino acids, or combinations thereof, and wherein at least 50% of the monomer units contain at least one amino group.

[0047] As disclosed herein, a contraceptive composition is a composition that prevents pregnancy in a female by preventing sperm from reaching one or more oocytes, thereby keeping the oocytes and sperm cells separate by a barrier method that may additionally help protect against sexually transmitted infections. By creating a barrier at the outer and inner cervix, sperm cells are retained in the vagina (or vaginal tract), thereby preventing sperm from reaching one or more oocytes. Thus, sperm cells will never enter the uterus through the cervix and will therefore have no chance of entering the fallopian tube (or uterine tube) to reach the oocytes. Instead, they will wait to be killed by the acidic fluid inside the vagina or be lost in "backflow".

[0048] As disclosed herein, an active ingredient is one or more compounds in a contraceptive composition that provides contraceptive ability, i.e., prevents pregnancy in a female by preventing sperm from reaching one or more oocytes.

[0049] A mucoadhesive polymer is a polymer that exhibits mucoadhesion. In this context, mucoadhesion is described as the interfacial force that holds two biomaterials together, such as the attraction between a biomaterial and mucus or mucosa. Thus, a mucoadhesive polymer refers to a polymer that has an attraction to mucus or mucosa.

[0050] Mucus is the protective covering of all epithelial surfaces, which keeps the epithelial layer moist and prevents microbial invasion of epithelial cells. A natural protective effect is achieved since mucus traps microbes and aids in their distal transport. When referring to the barrier effect achieved by a mucoadhesive polymer, it refers to the strengthening of mucus caused by the crosslinking of the polymer. The enhanced barrier effect is based on the tightness of the crosslinked mucus that prevents diffusion, and the duration for which the complex mucoadhesive polymer strengthens the mucus. The latter is determined by the natural turnover of mucus secreted by cells from the mucosa, which removes mucus containing the crosslinked polymer.

[0051] The rheology of the mucus layer on the cervical mucosa varies depending on the four phases of the menstrual cycle. During ovulation, the cervical mucus is loose, allowing sperm to pass through the gel and thus the mucus pore size also increases. The thickness of the barrier layer can be adjusted to be impermeable to relatively large cells such as sperm, yet it can also be adjusted to a tighter barrier layer, which may be required to be impermeable to bacteria, viruses, or other microbes or pathogens.

[0052] Considering that an effective barrier can be formed by thickening the cervical mucus, it is widely accepted that the cervical mucus barrier property can be used as a contraceptive method. Indeed, the main contraceptive mechanism of the levonorgestrel intrauterine system (LNG-IUS) and the progestin-only mini-pill is by thickening the cervical mucus. The method disclosed herein differs from these methods not in the nature of the barrier, but in the way the barrier is created: non-hormonal, non-invasive, contraceptive on demand, and without side effects.

[0053] Therefore, the mucoadhesive polymer provides a more reliable barrier effect, which prevents cells and microbes such as bacteria, viruses, and sperm from passing through the crosslinked mucus and diffusing into the mucosa. The vaginal contraceptive composition can produce such tightly crosslinked mucus that it prevents even the smallest microbes from passing through, thereby not only preventing pregnancy but also preventing sexually transmitted infections (STIs).

[0054] Thus, in one or more embodiments according to any aspect, the composition is a contraceptive composition. Additionally, the present invention provides a contraceptive composition that is hormone-free or free of chemicals with undesirable side effects. Undesirable effects may include embolism, migraine, or less severe side effects such as affecting the menstrual cycle. The effective time of the mucoadhesive polymer according to the present invention is determined by mucus turnover, which indicates that the contraceptive effect is temporary. After the effective time, contraception ends and fertility is not affected. The sufficient contraceptive time is affected by several factors such as the biological turnover of mucus, the concentration of the mucoadhesive polymer, etc. The contraceptive effect lasts for a period of time, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 hours, 1, 2, 3 days, or even up to 10 days, which is sufficient time to prevent sperm cells from entering the cervix. By preventing sperm from entering the cervix, the acidic environment of the vagina will reduce the motility of sperm and weaken them, so that they cannot fertilize the egg cell. Under natural conditions, sperm cells will need to enter the cervix within a few minutes to survive. Complete contraceptive effect is obtained from a single application, which means that the non-coherent use of the contraceptive composition provides the same protection as coherent use. Obtaining complete contraceptive effect from a single application can also mean that a brief contact of cervical mucus with the contraceptive composition can provide the same complete protection as continuous contact with cervical mucus.

[0055] The size of the mucoadhesive polymer allows molecules to diffuse within the mucus. This diffusion of the mucoadhesive polymer into the mucosa enables it to crosslink the mucus layer at a large thickness sufficient to prevent motile sperm from moving through the mucus, without causing mucus aggregation. The mucoadhesive polymer complexes with the mucus, thereby blocking the pores of the network and enhancing its barrier property. During ovulation, cervical mucus is loose, thus allowing sperm to pass through the gel and therefore the mucus pore size will also increase due to separation from non-ovulatory mucus. Therefore, the size of the mucoadhesive polymer should be adjusted in the direction of this increase in the pore size of ovulatory cervical mucus. When the pore size of cervical mucus does not increase due to ovulation, the size of the mucoadhesive polymer for the increased pore size of ovulatory cervical mucus still functions effectively.

[0056] In addition, the mucosal adhesion polymers are generally more soluble at lower molecular weights and have lower steric hindrance. If the mucosal adhesion polymer is large, it cannot pass through or fit through the pores of the mucus and thus it will end up interacting with an increased number of mucin molecules, whereby it does not diffuse through the gel. However, if it is too small, it can pass directly through without interacting with any mucin molecules. Therefore, a compromise is needed between a larger size (but not too large to avoid the mucosal adhesion polymer passing through the pores of the mucus all at once) and a smaller size (to obtain a solubility high enough for proper delivery to the subject's mucosa). Thus, the mucosal adhesion polymer can be delivered more effectively to the mucosa, which in turn allows for stronger and thus more effective crosslinking compared to the results obtainable with smaller or larger mucosal adhesion polymer molecules (less than 20,000 Da or greater than 100,000 Da).

[0057] The mucosal adhesion polymer is generally cationic, with at least 50% of the monomers being charged. The monomer units can (for example) contain an amino group, which is positively charged at physiological pH. It can also be hydrophobic, for example, where up to 50% of the monomers have hydrophobic side chains. These two features of the mucosal adhesion polymer can come into play if compatible excipients are chosen.

[0058] In chemistry, an amino group is a functional group consisting of a nitrogen atom bonded by a single bond to a hydrogen atom, an alkyl group, an aryl group, or a combination of these three. Organic compounds containing an amino group are called amines. Amines are derivatives of the inorganic compound ammonia, NH 3 When one, two, or all three hydrogens in ammonia are replaced by an alkyl or aryl group, the resulting compounds are called primary, secondary, or tertiary amines, respectively. Like ammonia, amines are weak bases because the unshared electron pair of the nitrogen atom can form a coordinate bond with a proton. Insoluble amines can be made soluble by adding an acid to form their water-soluble amine salts. The amino group makes the mucosal adhesion polymer basic, which is beneficial for their binding to the mucosa because it contains a large number of negatively charged molecules. Specifically, the basic amino group provides more effective crosslinking. Additionally, when some monomers (up to 50%) of the mucosal adhesion polymer contain hydrophobic groups, the mucosal adhesion polymer can also adhere to and diffuse into the mucosa to crosslink the mucosa without aggregating the mucus. In the context of the present invention, the amino group is -NH 2 , where one or both of the hydrogen atoms can be replaced by a group R, or the amino group can be a quaternary amino group with 3 R groups, i.e., -N + R 3 . R can be selected from C1-C4 alkyl groups, optionally substituted by one or more -OH, -SH, or -NH 2Substitution. When there is more than one R on the same nitrogen atom, these may be the same or different R groups. As long as R has 4 or fewer carbon atoms and specifically when the hydrogen atoms of the R group are replaced by one or more -OH, -SH, or -NH 2 substituted, the amino group as disclosed herein is generally regarded as basic. Longer alkyl chains (e.g., having 5 or more carbon atoms) can mask the basicity of the amino group. However, in the context of the present invention, an amino group with an alkyl group having 5 or more carbon atoms is still counted as an amino group. Similarly, the sugar may also contain an amide group, e.g., -CONHCH 3 or -NHCHO, but in the context of the present invention, these groups are not counted as amino groups.

[0059] In one or more embodiments according to any aspect, the amino group does not contain an alkyl group having 10 or more carbon atoms.

[0060] In one or more embodiments according to any aspect, the amino group does not contain an alkyl group having 9 or more carbon atoms.

[0061] In one or more embodiments according to any aspect, the amino group does not contain an alkyl group having 8 or more carbon atoms.

[0062] In one or more embodiments according to any aspect, the amino group does not contain an alkyl group having 6 or more carbon atoms.

[0063] In one or more embodiments according to any aspect, the amino group does not contain an alkyl group having 5 or more carbon atoms.

[0064] In one or more embodiments according to any aspect, at least 55% of the monomer units, such as at least 60% of the monomer units, such as at least 65% of the monomer units, such as at least 70% of the monomer units contain at least one amino group.

[0065] In one or more embodiments according to any aspect, one or more of the at least one amino group are primary amines. In the context of the present invention, a primary amine is an amino group in which any hydrogen atom has not been replaced by a group R substitution (i.e., -NH 2 ).

[0066] In one or more embodiments according to any aspect, the at least one amino group is a primary amine.

[0067] The vaginal contraceptive composition comprises one or more active ingredients and a physiologically acceptable gelling agent. The one or more active ingredients may be administered in a physiologically acceptable gelling agent (or carrier) which ensures that the one or more active ingredients are soluble under the conditions in which it is used and ensures that the one or more active ingredients are uniformly distributed in the target area. As used herein, uniformly distributed means that the target mucus area has been subjected to at least a minimum amount of the composition, where sufficient active ingredient diffuses into the mucus and enhances the mucus barrier.

[0068] A physiologically acceptable gelling agent (or carrier) means a non-toxic compound which is neither chemically nor physically toxic to human and / or animal organisms at an effective dose.

[0069] In one or more embodiments according to any aspect, the physiologically acceptable gelling agent is selected from hydroxyethyl cellulose (HEC), glycerol, hydroxypropyl methyl cellulose (HPMC), hydroxypropyl cellulose, guar gum or combinations thereof. Any suitable pharmaceutical gelling agent may be used provided that the gelling agent does not interact with the one or more active ingredients, in particular the mucoadhesive polymer.

[0070] By combining with a physiologically acceptable gelling agent, the contact area between the composition and the mucus is maximized. The increased contact area can help ensure that the maximum amount of mucoadhesive polymer can diffuse into the mucus layer and alter its properties. A high density of the composition also helps to increase diffusion. By having a high composition density, e.g., similar to the density of water, such as in a semi-solid gel, the applied composition is able to change shape and coat the entire surface of the cervical inlet.

[0071] Hydroxyethyl cellulose (or ethyl cellulose) is a gelling and thickening agent derived from cellulose. It is widely used in cosmetics, washing liquids and other household products. Hydroxyethyl cellulose and hydroxy methyl cellulose (or methyl cellulose) are often used together with hydrophobic drugs in capsule formulations to improve the dissolution of the drugs in gastrointestinal fluids. This process is called hydrophilization.

[0072] In one or more embodiments according to any aspect, the physiologically acceptable gelling agent is selected from hydroxyethyl cellulose, hydroxy methyl cellulose or combinations thereof.

[0073] Glycerol, also known as glycerine or glycerin, is a simple polyol compound. It is a colorless, odorless, viscous liquid which is sweet-tasting and non-toxic. The glycerol backbone is present in many lipids, which are called glycerides. It is widely used as a sweetening agent in the food industry and as a humectant in pharmaceutical formulations. Glycerol has three hydroxyl groups which are responsible for its solubility in water and its hygroscopicity.

[0074] In one or more embodiments according to any aspect, the physiologically available gelling agent is glycerol.

[0075] Hydroxypropyl methylcellulose (HPMC), also known as hypromellose, is a semi-synthetic, inert, viscoelastic polymer that is used as an excipient and controlled-delivery component in ophthalmic drops as well as oral pharmaceuticals, and is present in a variety of commercial products. As a food additive, hydroxypropyl methylcellulose is an emulsifier, thickener and suspending agent, and an alternative to animal gelatin. Its Codex Alimentarius code (E number) is E464.

[0076] In one or more embodiments according to any aspect, the physiologically available gelling agent is hydroxypropyl methylcellulose (HPMC).

[0077] Hydroxypropyl cellulose (HPC) is a derivative of cellulose that has both water solubility and organic solubility. It is used as an excipient, as well as a topical ophthalmic protectant and lubricant. HPC is a cellulose ether in which some of the hydroxyl groups in the repeating glucose monomers have been hydroxypropylated using propylene oxide, thus forming an -OCH 2 CH(OH)CH 3 group. The average number of substituted hydroxyl groups per glucose monomer is called the degree of substitution (DS). Complete substitution would provide a DS of 3. Since the added hydroxypropyl contains hydroxyl groups, this can also be etherified during the preparation of HPC. When this occurs, the molar number of hydroxypropyl per glucose ring, the molar substitution (MS), can be greater than 3.

[0078] In one or more embodiments according to any aspect, the physiologically available gelling agent is hydroxypropyl cellulose.

[0079] Guar gum, also known as guaran, is a galactomannan polysaccharide extracted from guar beans, which has thickening and stabilizing properties useful in food, feed and industrial applications. Depending on the application, the guar beans are mechanically dehulled, hydrated, ground and screened. It is usually produced as a free-flowing off-white powder. Chemically, guar gum is an extracellular polysaccharide composed of the sugars galactose and mannose. The main chain is a straight chain of β1,4-linked mannose residues, and galactose residues are 1,6-linked to this straight chain every other mannose, thus forming short side branches. Guar gum has the ability to withstand temperatures of 80 °C for 5 minutes.

[0080] In one or more embodiments according to any aspect, the physiologically available gelling agent is guar gum.

[0081] In one or more embodiments according to any aspect, the pharmaceutically acceptable gelling agent is a pharmaceutically acceptable carrier, wherein the pharmaceutically acceptable carrier can be water, dimethyl sulfoxide (DMSO), saline (salt solution), or a combination thereof.

[0082] In one or more embodiments according to any aspect, the vaginal contraceptive composition is not a foam.

[0083] A foam is an object formed by trapping air cavities in a liquid or solid. In most foams, the gas volume is large, and a liquid or solid film separates the gas regions.

[0084] The mucoadhesive polymer can be a polysaccharide, wherein C6 sugars are linked to each other by ether, ester, or amide bonds. C6 sugar monomers can be linked by (for example) any ether bond. For example, the C 1 and C 4 of two adjacent C6 sugars can be linked, or the C 1 and C 6 of two adjacent C6 sugars can be linked. Specifically, when the monomer is a C6 sugar, for example, glucose, monomers, for example, glucose monomers, can be linked by β1,4-bonds.

[0085] At least one amino group can be linked to any carbon atom of the glucose monomer, for example, C 2 or C 3 .

[0086] In one or more embodiments according to any aspect, the mucoadhesive polymer is composed of a plurality of monomer units linked to each other by ether bonds.

[0087] In one or more embodiments according to any aspect, the monomer units are selected from C6 sugars, amino-functionalized C6 sugars, or a combination thereof.

[0088] A C6 sugar is a carbohydrate whose molecule has 6 carbons (i.e., a hexose). The most well-known example of this class is glucose, which is a major component of cellulose and starch molecules.

[0089] An amino-functionalized C6 sugar (or amino sugar) is a sugar molecule in which a hydroxyl group has been replaced by an amine group. More than 60 amino sugars are known, and one of the most abundant is N-acetyl-D-glucosamine, which is a major component of chitin. The amino-functionalization can be located at the C 2 , C 3 , C 4 and / or C 6 of the C6 sugar.

[0090] In one or more embodiments according to any aspect, the monomer unit is an amino-functionalized C6 sugar.

[0091] In one or more embodiments according to any aspect, the monomer units are a combination of D-glucosamine and N-acetyl-D-glucosamine.

[0092] D-glucosamine (C 6 H 13 NO 5 ) is an amino sugar and an important precursor in the biochemical synthesis of glycoproteins and lipids. D-glucosamine is part of the structure of polysaccharides, chitosan, and chitin. D-glucosamine is one of the most abundant monosaccharides. It is commercially produced by hydrolysis of the exoskeletons of crustaceans, or less commonly, by fermentation of grains such as corn or wheat.

[0093]

[0094] Structure of D-glucosamine.

[0095] N-acetyl-D-glucosamine (GlcNAc, C 8 H 15 NO 6 ) is a derivative of a monosaccharide and glucose. It is prominent in a variety of biological systems. It is part of the biopolymer in bacterial cell walls, which is constructed from alternating units of GlcNAc and N-acetylmuramic acid (MurNAc), cross-linked by oligopeptides at the lactic acid residue of MurNAc. This layered structure is called peptidoglycan (previously called murein). GlcNAc is the monomer unit of the polymer chitin, which forms the outer covering of insects and crustaceans.

[0096]

[0097] Structure of N-acetyl-D-glucosamine.

[0098] In one or more embodiments according to any aspect, at least 50% of the monomer units are D-glucosamine, whereas 50% or less of the monomer units are N-acetyl-D-glucosamine, such as between 50% and 100% being D-glucosamine and between 0% and 50% being N-acetyl-D-glucosamine.

[0099] At least 50% of said monomer units being D-glucosamine means that at least 50% of the total monomers in said mucoadhesive polymer are from D-glucosamine. Similarly, 50% or less of said monomer units being N-acetyl-D-glucosamine means that 50% or less of the total monomers in said mucoadhesive polymer are from N-acetyl-D-glucosamine. Additionally, between 50% and 100% or between 0% and 50% means that between 50% and 100% or between 0% and 50% of the total monomers in said mucoadhesive polymer are from said monomer units, including all endpoints (0%, 50%, and 100%).

[0100] In one or more embodiments according to any aspect, at least 65% of said monomer units are D-glucosamine, whereas 35% or less of said monomer units are N-acetyl-D-glucosamine, such as between 65% and 100% being D-glucosamine and between 0% and 35% being N-acetyl-D-glucosamine. Endpoints are included.

[0101] In one or more embodiments according to any aspect, said mucoadhesive polymer is chitosan, wherein at least 50% of said glucose monomers have -NH 2 groups. Said chitosan can also be referred to as being at least 50% deacetylated.

[0102] Chitosan is a linear polysaccharide composed of randomly distributed β1,4-linked D-glucosamine (deacetylated units) and N-acetyl-D-glucosamine (acetylated units). It is prepared by treating the chitinous shells of shrimp and other crustaceans with an alkaline substance such as sodium hydroxide, or it can be extracted from other sources such as fungal cell walls.

[0103] When said mucoadhesive polymer is chitosan, it is important to avoid (for example) the presence of high molecular weight polyacrylic acid, because the carboxyl functional groups in the acrylic acid monomers form ionic complexes with the basic amino groups in the chitosan chains, which results in the formation of a highly swollen interpenetrating polymer network. This will cause mucus aggregation, thus causing the pores within the mucus to open and resulting in a weakened mucus barrier.

[0104] Chitosan is a strong mucoadhesive molecule, which means that it can entangle and bind to the mucin glycoproteins that make up the mucus gel. As such, it has been used in mucoadhesive drug delivery devices and is included in commercial hemostatic products. However, the chitosan used as disclosed herein typically has a high molar mass and thus diffuses poorly within the mucus gel and tends to cause mucus aggregation and compaction.

[0105] In one or more embodiments according to any aspect, said mucoadhesive polymer is chitosan, wherein at least 50% of said glucose monomers have -NH 2groups, and wherein 40% or less of said glucose monomers have -CONHCH 3 groups.

[0106] In one or more embodiments according to any aspect, said mucoadhesive polymer is chitosan, wherein at least 50% of said glucose monomers have -NH 2 groups, and wherein 20% or less of said glucose monomers have -CONHCH 3 groups.

[0107] In one or more embodiments according to any aspect, said mucoadhesive polymer is chitosan, wherein at least 70% of said glucose monomers have -NH 2 groups. Said chitosan may also be referred to as being at least 70% deacetylated.

[0108] In one or more embodiments according to any aspect, said mucoadhesive polymer is chitosan, wherein at least 70% of said glucose monomers have -NH 2 groups, and wherein 20% or less of said glucose monomers have -CONHCH 3 groups.

[0109] In one or more embodiments according to any aspect, said mucoadhesive polymer is selected from chitosan, chitosan-trimethyl, chitosan-mercaptoacetic acid, chitosan-iminothiolane, chitosan-thioethylamidine or combinations thereof.

[0110] Chitosan-trimethyl is a quaternized hydrophilic derivative of chitosan. This quaternized derivative of chitosan bears a positive charge and is soluble over a wide pH range.

[0111] Chitosan-mercaptoacetic acid, chitosan-iminothiolane and chitosan-thioethylamidine are chitosan-derivatives which have been modified by the introduction of different thiol groups. The thiol groups are introduced into chitosan by carbodiimide-mediated amide bond formation. Thereby, the properties of the resulting polymers are altered compared to the original polymer in terms of water solubility, mucoadhesion, biodegradability and in-situ gelation.

[0112] In one or more embodiments according to any aspect, said mucoadhesive polymer is chitosan, which has a molecular weight between 20,000 Da and 100,000 Da, such as between 30,000 Da and 90,000 Da, such as between 30,000 Da and 80,000 Da, such as between 30,000 Da and 70,000 Da, such as between 40,000 Da and 60,000 Da, such as between 45,000 Da and 55,000 Da. All endpoints within the above ranges are included.

[0113] In one or more embodiments according to any aspect, the mucoadhesive polymer is a peptide molecule having a length of 180 to 900 amino acids, which are linked by amide bonds. When the mucoadhesive polymer contains amino acids, any amino acids may be included as long as at least 50% of the amino acids have basic groups, or as the case may be as long as at least 50% of the amino acids have hydrophobic groups, or as long as at least 50% of the amino acids have thiol groups, or a combination of these 3 (basic, hydrophobic, and thiol). The mucoadhesive polymer is not limited to naturally occurring amino acids, but preferably, the amino acids are non-toxic and tolerated by the subject. Preferably, the mucoadhesive polymer does not contain D-amino acids, but any amino acids contained in the mucoadhesive polymer are L-amino acids.

[0114] Generally, the following amino acids are considered basic: arginine, lysine, histidine, ornithine, and β-alanine, and in one embodiment, the mucoadhesive polymer is a polypeptide of amino acids, wherein at least 50% of the amino acids are selected from the list consisting of arginine, lysine, histidine, ornithine, and β-alanine. The remaining amino acids may be selected from any amino acids, for example, any one of the 20 amino acids defined by the genetic code, but specifically glycine, serine, threonine, asparagine, and glutamine. Specific embodiments of the mucoadhesive polymer include polylysine, polyornithine, and / or polyarginine. The advantage of using basic amino acids is that they have excellent solubility in aqueous solutions.

[0115] In one or more embodiments according to any aspect, the mucoadhesive polymer is a peptide molecule having a length of 180 to 900 amino acids, wherein at least 50% of the amino acids have hydrophobic groups, and the amino acids are selected from the list consisting of: alanine, methionine, cysteine, phenylalanine, leucine, valine, and isoleucine. The remaining amino acids may be selected from the list consisting of: glycine, serine, threonine, asparagine, and glutamine, or the remaining amino acids may be selected from any amino acids, for example, any one of the 20 amino acids defined by the genetic code.

[0116] In one or more embodiments according to any aspect, the mucoadhesive polymer contains amino acids, wherein at least 50% of the amino acids are selected from the group consisting of arginine, lysine, histidine, ornithine, and β-alanine, or 50% of the amino acids have hydrophobic groups and are selected from the group consisting of alanine, methionine, cysteine, phenylalanine, leucine, valine, and isoleucine.

[0117] In one or more embodiments according to any aspect, the mucoadhesive polymer is a peptide molecule, which is linked by amide bonds, wherein at least 50% of the amino acids are selected from the list consisting of arginine, lysine, histidine, ornithine, and β-alanine. In another embodiment, at least 60% of the amino acids are selected from the list consisting of arginine, lysine, histidine, ornithine, and β-alanine. In another embodiment, at least 70% of the amino acids are selected from the list consisting of arginine, lysine, histidine, ornithine, and β-alanine.

[0118] In one or more embodiments according to any aspect, the mucoadhesive polymer is a peptide molecule, which is linked by amide bonds, wherein at least 50% of the amino acids are lysine. In another embodiment, at least 60% of the amino acids are lysine. In another embodiment, at least 70% of the amino acids are lysine.

[0119] In one or more embodiments according to any aspect, the mucoadhesive polymer comprises an amino acid, and the amino acid is L-lysine. In one or more embodiments according to any aspect, the mucoadhesive polymer is poly-L-lysine (PLL).

[0120] It is advantageous to use amino acids or hydrophobic amino acids because they are biodegradable. The protein-peptide interaction between the mucin and the polymer can improve mucoadhesion. In addition, amino acid polymers can be produced by bacterial recombination or synthetic production.

[0121] In one or more embodiments according to any aspect, the mucoadhesive polymer comprises sugar monomers, for example, both C6 sugar monomers and amino acids, wherein at least 50% of the monomers are basic, for example, having an amino group, or at least 50% of the monomers are hydrophobic, for example, having a hydrophobic group.

[0122] In one or more embodiments according to any aspect, the mucoadhesive polymer is composed of 40 to 800 monomer units that are connected to each other by ether bonds, ester bonds, amide bonds, or a combination thereof, such as 50 to 750 monomer units that are connected to each other by ether bonds, ester bonds, amide bonds, or a combination thereof, such as 75 to 700 monomer units, such as 100 to 650 monomer units, such as 150 to 600 monomer units. The size of the mucoadhesive polymer is extremely important because it ensures that the polymer is small enough to diffuse deeply into the mucus gel and large enough to form a tight crosslinked network. Tight means (for example) impermeable to microorganisms or sperm cells.

[0123] In one or more embodiments according to any aspect, the mucoadhesive polymer is selected from polymers having a low molecular weight, which should have a degree of polymerization (DP) providing a molecular weight in the range of 20 to about 100 kDa, which ensures the formation of a stable complex of the mucoadhesive polymer with mucus.

[0124] In one or more embodiments according to any aspect, the mucoadhesive polymer has a molecular weight between 20,000 Da and 90,000 Da, such as between 30,000 Da and 80,000 Da, such as between 30,000 Da and 70,000 Da, such as between 40,000 Da and 60,000 Da, such as between 45,000 Da and 55,000 Da. All endpoints within the above ranges are included.

[0125] The size of the polymer ensures that the polymer is soluble under the conditions of use and that the polymer can diffuse through the pores of the mucus and form a thick and tight barrier.

[0126] The mucoadhesive polymer should be stable in the environment of the target mucosa, which is the low pH in the female abdomen. Thus, the pH range in which the mucoadhesive polymer is stable is in the range of 1 - 8. Depending on the pH environment, different types and sizes of polymers can be used.

[0127] In one or more embodiments according to any aspect, the pH of the vaginal contraceptive composition is between 2.0 and 7.0, such as between 2.5 and 6.5, such as between 3.0 and 6.0. All endpoints within the above ranges are included.

[0128] The pH of the composition being between 2.0 and 7.0 means that if measured, the pH is between these two values and the mucoadhesive polymer is stable within this range. If the composition is applied to the female abdomen, especially the female vagina, and the pH value range is 3 to 5 here, the lower pH of the composition is preferred.

[0129] Diffusion of the mucoadhesive polymer occurs when the mucoadhesive polymer and the physiologically acceptable gelling agent adhere to the mucus. Due to its degree of polymerization and degree of acetylation (which provides excellent mucoadhesion), the use of the mucoadhesive polymer in therapy is possible. This allows the polymer to diffuse into the mucus and temporarily block the pores of the mucus. This occurs due to the temporary cross-linking effect of the mucus, which is controlled by the normal turnover of the mucus and the biodegradability of the mucoadhesive polymer. Thus, the effective cross-linking time can be adjusted by subjecting the mucus to different concentrations of the mucoadhesive polymer, such as (for example) concentrations in the range of 1 mg / mL to 100 mg / mL, such as 1 mg / mL to 75 mg / mL, such as 1 mg / mL to 50 mg / mL, such as 1 mg / mL to 25 mg / mL, such as concentrations in the range of 5 mg / mL. All endpoints within the above ranges are included.

[0130] In one or more embodiments according to any aspect, the mucoadhesive polymer is present at a concentration between 0.05 wt.% and 10.0 wt.% of the total weight of the vaginal contraceptive composition, such as between 0.5 wt.% and 10.0 wt.% of the total weight of the vaginal contraceptive composition, such as between 1.0 wt.% and 10.0 wt.%, such as between 2.5 wt.% and 10.0 wt.%, such as between 5.0 wt.% and 10.0 wt.%, such as between 0.05 wt.% and 10.0 wt.%, such as between 0.05 wt.% and 8.0 wt.%, such as between 0.05 wt.% and 6.0 wt.%, such as between 0.05 wt.% and 4.0 wt.%.

[0131] Between 0.05 wt.% and 10.0 wt.% means that 0.05% to 10.0% of the total weight of the vaginal contraceptive composition is from the mucoadhesive polymer. All endpoints within the above ranges are included.

[0132] Due to its adhesiveness and size, the mucoadhesive polymer will penetrate through the mucus and diffuse to the mucus surface to form a thick layer. The mucoadhesive polymer will then complex with the mucus and thereby seal the pores of the network, providing an enhanced barrier to the mucus. When the mucus is enhanced, it is impermeable to particles and prevents (for example) externally introduced liquids, particles, and cells, such as sperm, from passing through. The complex formed in the mucus can be specific to cells of a particular size and is thereby impermeable to virus particles (or viruses) in the range of 20 to 30 nm in size, mycoplasmas in the range of 0.3 microns, bacteria in the range of 0.5 to 5 microns, or sperm in the range of 3 microns.

[0133] The composition according to the present invention comprises a mucoadhesive polymer and a pharmaceutically acceptable gelling agent (as a contraceptive), since the treated mucus will be temporarily impermeable to sperm. The contraceptive effect associated with the present invention represents a reversible and temporary prevention of pregnancy due to a non-surgical and hormone-free barrier effect achieved by a single use, which means that the contraceptive effect is achieved by a single application and does not require a certain concentration to be present over a period of time as in the case of (for example) hormonal pills such as combined oral contraceptive pills (commonly referred to as birth control pills or colloquially as "the pill").

[0134] The temporary effect means that when applied to mucus, the effect of the mucoadhesive polymer is reversible. The rate at which the reversal will occur is determined by the amount of polymer diffusing into the mucus and the biological turnover of the mucus itself.

[0135] In another aspect, the present invention is a kit of parts which comprises the vaginal contraceptive composition and an applicator, the vaginal contraceptive composition comprising the mucoadhesive polymer and a physiologically acceptable gelling agent, for example, the contraceptive composition as described above. In one embodiment, the applicator is a delivery device using the following method, wherein the applicator contains the vaginal contraceptive composition in gel form and is inserted into the vagina by a syringe or by introducing a soft gel capsule which dissolves in the vagina, thereby releasing the gel. The gel is deployed from the applicator and applied to the cervical mucus; thus, the mucus is crosslinked by the mucoadhesive polymer. In one embodiment, the applicator is a container which contains the vaginal contraceptive composition and which can be emptied by an emptying mechanism.

[0136] The composition comprising the mucoadhesive polymer and a physiologically acceptable gelling agent can be part of a kit which further includes an applicator. The applicator can be used to apply the composition to (for example) the cervical surface.

[0137] In one embodiment, the applicator is a syringe. In another embodiment, the applicator is a soft gel capsule.

[0138] In other embodiments, the kit comprises the vaginal contraceptive composition, an applicator and instructions for use.

[0139] The vaginal contraceptive composition according to any embodiment can be used at any time of the day, prior to sexual intercourse. Preferably, 24 hours to 30 seconds prior to sexual intercourse. The vaginal contraceptive composition can be used for the purpose of preventing pregnancy and can be administered vaginally in an amount between 1 and 5 mL using a syringe or a flexible gel capsule. The vaginal contraceptive composition is inserted vaginally using a finger or an applicator.

[0140] The present invention is further illustrated by the following examples, and the following examples should not be regarded as limiting the scope of protection. The features disclosed in the above description and the following examples can be implemented alone or in any combination thereof in different forms of materials for implementing the present invention.

[0141] In the following, a plurality of embodiments are described with reference to the accompanying drawings. It should be noted that the accompanying drawings are only intended to assist in the description of the embodiments. They are not intended as an exhaustive description of the claimed invention or as a limitation on the scope of the claimed invention. Additionally, the described embodiments do not need to have all aspects or advantages shown. The aspects or advantages described in connection with a particular embodiment are not necessarily limited to that embodiment and can still be practiced in any other embodiment even if not so stated or even if not so explicitly described.

[0142] Example

[0143] In this article, it has been shown that low molar mass chitosan (below 2,000 Da) can modify porcine gastric mucin and the hydrogel of the mucus layer produced by colonic cell lines, which will enhance the barrier property and slow down the diffusion of dextran polymers and cholera toxin subunits through the hydrogel.

[0144] Although all mucus gels have similar characteristics, they still differ in some aspects. This includes mucin contraction (e.g., pore size), mucin concentration, and the types of associated proteins and lipids, as well as salt concentration. Additionally, they also differ in environmental factors such as pH, exposure to shear stress, exposure to bacteria, and different turnover rates. Given these differences, it is not obvious that a treatment designed for porcine mucin hydrogels will still play a role in enhancing the barrier property of cervical mucus.

[0145] Example 1

[0146] We used a series of chitosan types that differed mainly in molar mass and the tissue source (animal vs. fungus) from which they were extracted to conduct experiments to test the ability of chitosan to interact with human ovulatory cervical mucus and to diffuse within human ovulatory cervical mucus, as well as their ability to enhance the barrier of human ovulatory cervical mucus against human sperm.

[0147] Materials and Methods

[0148] Chitosan labeling

[0149] Using the modified method previously reported by Kootala et al., 2018 (Kootala, Sujit, Luimar Filho, Vaibhav Srivastava, Victoria Linderberg, Amani Moussa, Laurent David, Stéphane Trombotto, and Thomas Crouzier. 2018. “Reinforcing Mucus Barrier Properties with Low Molar Mass Chitosans.” Biomacromolecules 19(3):872–82), chitosan (CS) and chitosan oligomers (CO) were labeled with fluorescein isothiocyanate (FITC) (Sigma-Aldrich). Briefly, a solution of 40 mg / ml chitosan in 2 ml lactic acid (pH 5) was prepared, 2 ml of methanol was added and the mixture was treated with 2 M HCl or 2 M NaOH to adjust the pH to 5.5. Then, a solution of 10 mg / ml FITC in DMSO was added to achieve a ratio of 1:50 (one fluorescein per 50 monomers), and then the mixture was shaken for 2 h in the dark at room temperature. Except for 10 ml of ethanol, chitosan was precipitated by successively adding 2 mL of 2 M NaOH to increase the pH to 9. After centrifugation at 20,000×g for 25 min at 4 °C, the supernatant was removed. Then, the particles were rinsed three times by resuspending the particles in ethanol and then centrifuging at 20,000×g for 10 min at 4 °C and removing the supernatant to extract unconjugated FITC. After removing ethanol by rotary evaporation for 2 h, the particles were frozen with liquid nitrogen, freeze-dried and stored at 4 °C.

[0150] Table 1. Characteristics of the chitosans used. DDA: degree of deacetylation; Mw: molecular weight; NC: not calculable.

[0151] Chitosan (identification name) DDA (%) Mw (kDa) ZXP1 NC 0.4(±2.6％) CO NC 1.4(±0.7％) Z49 98.9 7.1(±0.4％) 95 / 5 98.5 35.0(±0.1％) Z56 93.7 18.9(±0.3％) Z13 91.6 27.9(±0.3％) Z10 97.4 36.2(±0.2％) 95 / 100 95.0 150.0(±0.2％) Z43 96.9 251.8(±0.2％)

[0152] Turbidity test

[0153] Transmittance was measured by turbidity test at 600 nm using a Varian Cary 50 Bio UV-visible spectrophotometer (Agilent Technologies, USA). Samples containing 2.7% hydroxyethyl cellulose were transferred to cuvettes and centrifuged at 600×g for 5 min in 50 ml plastic tubes to remove air pockets.

[0154] Semen evaluation

[0155] Semen samples from patients and volunteers collected at the Andrology, Sexual Medicine, Transmedicine, clinic (ANOVA, Karolinska University Hospital, Sweden) were subjected to standard semen kinematic analysis and sperm penetration assays were performed within 3 h after collection. Data on collection time, abstinence time, and semen volume were obtained. After complete ejaculation by masturbation, the semen was gently liquefied for 30 min on an oscillator in an incubator heated to 37 °C. Semen viscosity was determined visually and by pipetting. Semen was analyzed microscopically by pipetting 6 μl of the sample into a pre-warmed (Netherlands) counting chamber slide (20 μm). Subsequently, the sample was evaluated using a clinical ECLIPSE 50i microscope (Nikon Instruments, Japan) with a total magnification of 5×, equipped with a tabletop heater MS100 (37 °C, Linkam Scientific Instruments, UK), a 10× objective lens (Ph1), and a 0.5× charge-coupled device camera UI-1540LE-M-HQ (IDS Imaging Development Systems GmbH, Germany). The system was connected to computer-assisted semen analysis software QualiSperm (v3.0.9.486, AKYme, Switzerland). In addition to sperm density [106 / ml], progressive motility [%], motility [%], immotility [%], velocity [μm / s], sperm size [μm2], and cell count were measured. Semen samples meeting the following criteria were included in the study: volume > 1.5 ml, concentration > 15 × 106 / ml, and progressive motility > 40%. These criteria reflect the reference limits of the World Health Organization (WHO) (“WHO Laboratory Manual for the Examination and Processing of Human Semen” 2010) and (Lars 2011. “What Is Normal Semen Quality?On the Use and Abuse of Reference Limits for the Interpretation of Semen Analysis Results.” Human Fertility 14(3):179–86) and the normal sperm values described therein. Ten values were generated by evaluating 5 fields of view in two chambers for each run.

[0156] Cervical mucus evaluation

[0157] Ovulatory cervical mucus (CVM) (the CVM with the highest permeability) was collected from healthy donors at the University Hospital of Carolinum. The donors did not use hormonal contraceptives, were aged between 18 and 30 years, had a BMI of 19 - 25, were non-smokers and were neither on drug treatment nor suffering from chronic diseases. Before collecting the CVM, the hormonal status of each healthy, regularly cycling volunteer was checked by blood tests in the laboratory of Carolinum University. At the time of donation, the levels of FSH, LH and estradiol in the women were analyzed to demonstrate the prevalence of ovulation. Mucus was collected at the external orifice using an endometrial catheter Gynebiops standard CH9 (GYNEAS, France) and a Pipelle de Cornier (PRODiMED, France) for endometrial biopsy.

[0158] In vitro fluorescence curve of chitosan diffusion into cervical mucus

[0159] To determine the diffusion distance and amount of chitosan accumulated in CVM at ovulation, a modified capillary diffusion assay according to Wu et al. was implemented (Seyoum Ayehunie, Ying-Ying Wang, Timothy Landry, Stephanie Bogojevic, and Richard A. Cone. 2018. “Hyperosmolal Vaginal Lubricants Markedly Reduce Epithelial Barrier Properties in a Three-Dimensional Vaginal Epithelium Model.” Toxicology Reports 5 (January): 134–40). A 0.5% (w / v) labeled chitosan (chitosan-FITC) was adjusted to pH 5.5 (pH ± 0.02) by using 0.1 / 1 M hydrochloric acid (HCl, Merck KGaA, Germany), 0.1 / 1 M sodium hydroxide (NaOH, CPAchem Ltd., Bulgaria) or 50% NaOH (Sigma-Aldrich, USA).

[0160] By using a syringe with a Luer connector (Hilgenberg GmbH, Germany) and 1 ml A customized square capillary (L 60 mm, ID 0.3×0.3 mm, OD 0.45×0.45 mm, borosilicate glass) of a syringe (Henke-Sass Wolf GmbH, Germany) was used to aspirate CVM into two capillaries. Then, the tubes were broken at the Luer-connection and the cut ends were sealed with wax (Paul Marienfeld GmbH & Co. KG, Germany). This resulted in airtight capillaries completely filled with CVM. The septum of a short-threaded cap (55° Shore hardness, Teknolab Sorbent AB, Sweden) was pierced with the sealed end of the capillary, the cap was placed on a short-threaded glass vial (ND9, 1.5 ml, VWR, USA) and the open end was gently inserted into 300 μl of pre-warmed buffer solution or a solution of chitosan-FITC in buffer. The CVM treated with buffer solution in the capillary was used as a negative control. At the same time, the same square capillary without Luer connector (L 50 mm, ID 0.3×0.3 mm, borosilicate glass, CM Scientific Ltd., UK) was filled with chitosan-FITC solution by inserting the capillary into a glass vial containing 300 μl of 0.5% or 0.1% chitosan-FITC (serving as a positive control and reference fluorescence intensity). After incubation at 37 °C and 5% CO 2 After 30 min of incubation, the capillaries were evaluated by fluorescence microscopy and images were recorded in the exposure time range of 0.01 s - 1 s. Images were acquired using an Eclipse Ti inverted microscope (Nikon, Japan), a Zyla sCMOS camera (5.5 MP, Andor, Oxford Instruments, UK) and a light source pE-300lite (10 ms, CoolLED, UK) connected to NIS-Elements BR 4.60.00 software (Nikon, Japan). Filter B for green fluorescence and a 2× objective were used. The images acquired at an exposure time of 20 ms provided non-saturated images for optimal identification of fluorescence intensity differences between different CSs and for calculation of the amount of chitosan in CVM. At an exposure time of 800 ms, the fluorescence signal saturated at the capillary starting point, but low chitosan-FITC concentrations were observed deeper inside the capillary, so the maximum diffusion distance was acquired.

[0161] The exported images were analyzed using ImageJ software (version 2.0.0-rc-43 / 1.52b, USA). Rectangles (h = 15, w = 1314) were drawn in the middle of each capillary starting 5 mm before the interface of air and CVM in the capillary, and chitosan-FITC accumulation was also obtained at the interface. The fluorescence intensity was plotted against the distance (in pixels). Each pixel corresponded to 3 μm. At an exposure time of 800 ms, the buffer-treated CVM showed a background signal, so the values obtained with the chitosan-FITC-treated CVM were subtracted from the obtained values.

[0162] By using control capillaries with known chitosan-FITC concentrations, the fluorescence intensity with unknown chitosan-FITC concentrations along the capillary could be converted into chitosan-FITC concentrations. Using Prism 8 (GraphPad, USA), the relative amount of chitosan accumulated at 20 ms and the relative fluorescence intensity along the capillary at 800 ms were plotted. By calculating the area under the curve (AUC) of the samples analyzed at 0.02 s, chitosan-FITC accumulation was obtained.

[0163] Phase contrast microscopy of sperm penetration

[0164] After liquefaction and evaluation of semen and CVM, 100 μl of only buffer and a solution of chitosan in buffer were filled into glass vials (ND9, 1.5 ml, VWR, USA) sealed with caps having a septum (Shore hardness 55°, Teknolab Sorbent AB, Sweden) and preheated at 37 °C. Aliquots of ovulatory CVM were aspirated into two custom-made capillaries and the capillaries were sealed at the open ends as described above. The septum of the cap was penetrated by the sealed end of the capillary filled with CVM. First, the capillary inserted through the cap was placed in a glass vial containing the chitosan solution at 37 °C for 30 min (inserted 5 mm deep into the solution). Then, at 37 °C, the capillary was transferred to a glass vial containing 100 μl of semen for sperm penetration for 30 min (inserted 5 mm deep into the solution). For a control experiment, the same process was repeated, but the chitosan solution was replaced with only buffer solution. For another control experiment, the same process was repeated but the capillary filled with ovulatory CVM was directly immersed in sperm. After incubation, the capillary was placed on a custom-made microscope slide marked with distances of 0.5, 1, 2, 3, 4, and 5 cm and placed on a preheated (37 °C) tabletop heater DC 95 (Linkam Scientific Instruments, UK) and observed through a microscope.

[0165] Videos were recorded at marked distances on a glass slide, including the capillary starting point (0.1 cm), using an Eclipse Ci phase contrast microscope (Nikon, Japan) equipped with a UI-3240LE-C-HQ camera (IDS Imaging Development Systems, Germany). A 10× magnification was used for the objective lens (Ph1) and the camera, resulting in a total magnification of 100×. The recorded microscopic field of view was 0.21 × 0.27 mm, equivalent to 0.0567 mm2. At each distance, a resolution of 1280 × 1024 pixels was used to record videos of 3 fields of view at 30 frames per second. Recording started at the upper, outer surface of the capillary and then focused through the capillary until reaching the lower surface, resulting in a 3-D scan through the capillary. Sperm were counted by volume (0.017 mm 3 ). The assays were repeated three times using semen from different volunteers.

[0166] Results of Example 1

[0167] The effect of chitosan molar mass was demonstrated by testing the diffusion of fluorescently labeled chitosans of different sizes through human ovulatory cervical mucus. For both chitosans of animal origin (extracted from the shells of crustaceans, CO, 95 / 5 and 95 / 100) and fungal-based chitosans (Z49, Z56, Z13, Z10, Z43), the results ( Figures 1A - 1I 、 Figure 2 ) clearly showed that smaller chitosans penetrated deeper and accumulated more in the mucus. It is very noteworthy that large chitosans (>100 kDa) could not penetrate within the mucus gel network, which may be due to steric hindrance and thus would not accumulate in the mucus. This would create a very superficial barrier, which may be very sensitive to rupture by shear stress, for example. Therefore, chitosans above 100 kDa were excluded for this purpose.

[0168] The effect of chitosan molar mass on the barrier properties of human ovulatory cervical mucus was tested using formulations containing chitosans of different molar masses. By using sperm penetration assays, human sperm and ovulatory cervical mucus, it was possible to identify that smaller chitosans, which are effective in enhancing porcine gastric mucin hydrogels and mucus expressed by colon cell lines, could not prevent the penetration of human sperm through the mucus. This was well-evidenced for CO chitosan in pH 5.5 and lactate buffer in a variety of different buffer systems ( Figures 3A - 3C ). Even when CO was formulated in combination with a larger chitosan (95 / 5), the formulation did not provide a barrier-enhancing effect.

[0169] Similarly, it has been shown that fungal chitosans of 7.1 and 18.9 kDa (Z49 and Z56, respectively) were also ineffective in preventing sperm penetration (Figures 4A - 4E )。In contrast, it was found that by using fungal chitosan greater than 20 kDa (e.g., Z10), compared to the control group (untreated mucus) and compared to mucus treated with only chitosan dissolution buffer, the average sperm penetration was significantly reduced ( Figures 4A - 4E ).

[0170] A size-dependence for the effective barrier enhancing effect was also shown for crustacean shell-derived chitosan ( Figures 5A - 5D ). In these assays, larger chitosan (150 kDa) could also prevent sperm penetration. However, the chitosan diffusion results ( Figures 1A - 1I and Figure 2 ) clearly showed the poor penetration of larger chitosan (150 kDa) in mucus. Thus, the barrier formed by larger chitosan (150 kDa) was due to a thin cross-linked layer at the mucus gel interface. In the well-controlled conditions of in vitro sperm penetration assays, this thin cross-linked layer could indeed result in a barrier to sperm. However, this thin layer was unlikely to withstand the shear and convective movements common in vivo. Instead, the deeper penetration of chitosan between 20 kDa and 100 kDa would constitute a more robust barrier in vivo. We conclude that the optimal chitosan for enhancing the barrier properties of human ovulatory cervical mucus is in the range of 20 kDa to 100 kDa, as these chitosans combine deep penetration in mucus with their ability to form an effective barrier to sperm.

[0171] For the correct delivery of chitosan to the cervical canal, the chitosan formulation should contain excipients that increase the viscosity of the solution to increase the residence time of the formulation and avoid leakage. It is important that the excipients do not interact with chitosan, thus allowing complete interaction with mucus components. The selected gel excipients should at least be known for their excellent biocompatibility, not have negative charges that can interact with the positive charge changes of chitosan, and not have known interactions with chitosan. The compatibility of hydroxyethyl cellulose with chitosan was tested by measuring the transmittance of the mixture. The absence of a change in transmittance indicated the absence of chitosan precipitation and the excellent compatibility of chitosan with hydroxyethyl cellulose as a thickening agent ( Figure 6 ). The addition of fungal chitosan (Z10, 36.2 kDa) or animal-derived chitosan (CO, 1.4 kDa; 95 / 5, 35 kDa) at 0.5% (w / v) did not change the transmittance, indicating the absence of precipitation and the excellent solubility of chitosan in these formulations. Glycerol and hydroxyethyl cellulose were also combined with chitosan to test for possible changes in chitosan penetration in human ovulatory cervical mucus. The results showed that these excipients did not change the penetration of chitosan into ovulatory cervical mucus ( Figures 7A - 7C ). Figures 7A - 7CThe decrease in fluorescence marks the maximum diffusion distance of chitosan alone and chitosan blended with excipients after 30 minutes of exposure to mucus. The presence of the tested excipients also did not alter the barrier-enhancing effect on ovulatory cervical mucus( Figures 8A - 8C ).

[0172] Example 2

[0173] This example will demonstrate the mucus enhancement of "amino acid monomers". In this example, the penetration of human sperm into human ovulatory cervical mucus that was first exposed to a poly-L-lysine (PLL) solution was tested. Figure 9A and Figure 9B The results are provided in

[0174] and show sperm penetration assays performed on human ovulatory mucus. Sperm counts were evaluated 30 minutes after exposure to undiluted sperm.

[0175] Figure 9A (Left and right panels) show human ovulatory cervical mucus exposed to a solution of low molecular weight poly-L-lysine (wPLL, 1.6 kDa) in 32.5 mM lactate buffer, exposed to lactate buffer (32.5 mM), or unaltered human ovulatory cervical mucus (w / o). Figure 9B (Left and right panels) show human ovulatory cervical mucus exposed to a solution of high molecular weight poly-L-lysine (wPLL, 66 kDa) in 32.5 mM lactate buffer, exposed to lactate buffer (32.5 mM), or unaltered human ovulatory cervical mucus (w / o).

[0176] Results of Example 2

[0177] From the results, it can be inferred that PLL compounds can enhance the barrier of human ovulatory cervical mucus against sperm. Similar to chitosan, low molecular weight PLL has no effect. Only the higher molecular weight can prevent sperm entry. The point where no sperm are observed further into the mucus (for 66 kDa PLL, approximately 3 cm) is similar to some chitosans, such as 7.1 kDa chitosan (approximately 2 cm, Figure 4A ), but further than other chitosans, such as 27.9 kDa and 36.2 kDa (approximately 0.5 cm, Figure 4C and Figure 4D ).

[0178] The present invention will be described below by the following non-limiting items.

[0179] 1. A vaginal contraceptive composition comprising one or more active ingredients and a physiologically acceptable gelling agent, wherein at least one of the one or more active ingredients is a mucoadhesive polymer, wherein the mucoadhesive polymer has a molecular weight between 20,000 Da and 100,000 Da, wherein the mucoadhesive polymer is composed of a plurality of monomer units connected to each other by ether bonds, ester bonds, amide bonds or combinations thereof, wherein the monomer units are selected from C6 sugars, amino-functionalized C6 sugars, amino acids or combinations thereof, and wherein at least 50% of the monomer units contain at least one amino group.

[0180] 2. The vaginal contraceptive composition according to any of the above items, wherein the vaginal contraceptive composition is not a foam.

[0181] 3. The vaginal contraceptive composition according to any of the above items, wherein the mucoadhesive polymer has a molecular weight between 20,000 Da and 90,000 Da.

[0182] 4. The vaginal contraceptive composition according to any of the above items, wherein the mucoadhesive polymer has a molecular weight between 20,000 Da and 75,000 Da.

[0183] 5. The vaginal contraceptive composition according to any of the above items, wherein the mucoadhesive polymer has a molecular weight between 20,000 Da and 60,000 Da.

[0184] 6. The vaginal contraceptive composition according to any of the above items, wherein the mucoadhesive polymer has a molecular weight between 30,000 Da and 50,000 Da.

[0185] 7. The vaginal contraceptive composition according to any of the above items, wherein the mucoadhesive polymer has a molecular weight between 30,000 Da and 40,000 Da.

[0186] 8. The vaginal contraceptive composition according to any of the above items, wherein the mucoadhesive polymer is composed of a plurality of monomer units connected to each other by ether bonds.

[0187] 9. The vaginal contraceptive composition according to any of the above items, wherein at least 55% of the monomer units contain at least one amino group.

[0188] 10. The vaginal contraceptive composition according to any of the above items, wherein at least 60% of the monomer units contain at least one amino group.

[0189] 11. The vaginal contraceptive composition according to any of the above items, wherein at least 65% of the monomer units contain at least one amino group.

[0190] 12. The vaginal contraceptive composition according to any of the above items, wherein at least 70% of the monomer units comprise at least one amino group.

[0191] 13. The vaginal contraceptive composition according to any of the above items, wherein one or more of the at least one amino group are primary amines.

[0192] 14. The vaginal contraceptive composition according to any of the above items, wherein the monomer units are selected from C6 sugars, amino-functionalized C6 sugars, or combinations thereof.

[0193] 15. The vaginal contraceptive composition according to any of the above items, wherein the monomer unit is an amino-functionalized C6 sugar.

[0194] 16. The vaginal contraceptive composition according to any of the above items, wherein the monomer unit is a combination of D-glucosamine and N-acetyl-D-glucosamine.

[0195] 17. The vaginal contraceptive composition according to item 16, wherein at least 50% is D-glucosamine.

[0196] 18. The vaginal contraceptive composition according to any one of items 16 - 17, wherein 50% or less is N-acetyl-D-glucosamine.

[0197] 19. The vaginal contraceptive composition according to any one of items 16 - 18, wherein 50% to 100% is D-glucosamine.

[0198] 20. The vaginal contraceptive composition according to any one of items 16 - 19, wherein 0% to 50% is N-acetyl-D-glucosamine.

[0199] 21. The vaginal contraceptive composition according to any one of items 16 - 20, wherein at least 65% is D-glucosamine.

[0200] 22. The vaginal contraceptive composition according to any one of items 16 - 21, wherein 35% or less is N-acetyl-D-glucosamine.

[0201] 23. The vaginal contraceptive composition according to any one of items 16 - 22, wherein 65% to 100% is D-glucosamine.

[0202] 24. The vaginal contraceptive composition according to any one of items 16 - 23, wherein 0% to 35% is N-acetyl-D-glucosamine.

[0203] 25. The vaginal contraceptive composition according to any one of items 1 - 7, wherein the mucoadhesive polymer is a peptide molecule 180 to 900 amino acids in length, linked by amide bonds.

[0204] 26. The vaginal contraceptive composition according to item 25, wherein the mucoadhesive polymer is a polypeptide of amino acids, and at least 50% of the amino acids are selected from the list consisting of arginine, lysine, histidine, ornithine, and β-alanine.

[0205] 27. The vaginal contraceptive composition according to any one of items 25 - 26, wherein the mucoadhesive polymer comprises polylysine, polyornithine, and / or polyarginine.

[0206] 28. The vaginal contraceptive composition according to item 27, wherein the mucoadhesive polymer comprises polylysine.

[0207] 29. The vaginal contraceptive composition according to any one of items 1 - 7, wherein the mucoadhesive polymer is a peptide molecule having a length of 180 to 900 amino acids, at least 50% of the amino acids having a hydrophobic group, the amino acids being selected from the list consisting of alanine, methionine, cysteine, phenylalanine, leucine, valine, and isoleucine, and the remaining amino acids being optionally selected from the list consisting of glycine, serine, threonine, asparagine, and glutamine.

[0208] 30. The vaginal contraceptive composition according to any one of items 1 - 7, wherein the mucoadhesive polymer comprises amino acids, at least 50% of the amino acids being selected from the group consisting of arginine, lysine, histidine, ornithine, and β-alanine, or 50% of the amino acids having a hydrophobic group and being selected from the group consisting of alanine, methionine, cysteine, phenylalanine, leucine, valine, and isoleucine.

[0209] 31. The vaginal contraceptive composition according to any one of items 1 - 7, wherein the mucoadhesive polymer is a peptide molecule linked by amide bonds, and at least 50% of the amino acids are selected from the list consisting of arginine, lysine, histidine, ornithine, and β-alanine.

[0210] 32. The vaginal contraceptive composition according to item 31, wherein at least 60% of the amino acids are selected from the list consisting of arginine, lysine, histidine, ornithine, and β-alanine.

[0211] 33. The vaginal contraceptive composition according to any one of items 31 - 32, wherein at least 70% of the amino acids are selected from the list consisting of arginine, lysine, histidine, ornithine, and β-alanine.

[0212] 34. The vaginal contraceptive composition according to any one of items 1-7, wherein the mucoadhesive polymer is a peptide molecule, which is connected by amide bonds, and at least 50% of the amino acids are lysine.

[0213] 35. The vaginal contraceptive composition according to item 34, wherein at least 60%, such as at least 70% of the amino acids are lysine.

[0214] 36. The vaginal contraceptive composition according to any one of items 1-7, wherein the mucoadhesive polymer comprises amino acids, and the amino acids are L-lysine.

[0215] 37. The vaginal contraceptive composition according to item 36, wherein the mucoadhesive polymer is poly-L-lysine (PLL).

[0216] 38. The vaginal contraceptive composition according to any of the above items, wherein the physiologically available gelling agent is selected from hydroxyethyl cellulose (HEC), glycerol, hydroxypropyl methyl cellulose (HPMC), hydroxypropyl cellulose, guar gum or a combination thereof.

[0217] 39. The vaginal contraceptive composition according to any of the above items, wherein the mucoadhesive polymer is composed of 40 to 800 monomer units connected to each other by ether bonds, ester bonds, amide bonds or a combination thereof.

[0218] 40. The vaginal contraceptive composition according to any of the above items, wherein the mucoadhesive polymer is composed of 50 to 750 monomer units connected to each other by ether bonds, ester bonds, amide bonds or a combination thereof.

[0219] 41. The vaginal contraceptive composition according to any of the above items, wherein the mucoadhesive polymer is composed of 75 to 700 monomer units connected to each other by ether bonds, ester bonds, amide bonds or a combination thereof.

[0220] 42. The vaginal contraceptive composition according to any of the above items, wherein the mucoadhesive polymer is composed of 100 to 650 monomer units connected to each other by ether bonds, ester bonds, amide bonds or a combination thereof.

[0221] 43. The vaginal contraceptive composition according to any of the above items, wherein the mucoadhesive polymer is composed of 150 to 600 monomer units connected to each other by ether bonds, ester bonds, amide bonds or a combination thereof.

[0222] 44. The vaginal contraceptive composition according to any of the above items, wherein the concentration of the mucoadhesive polymer is 0.05 wt.% to 10.0 wt.% of the total weight of the vaginal contraceptive composition.

[0223] 45. A vaginal contraceptive composition according to any of the above items, wherein the pH of the composition is from 2.0 to 7.0.

[0224] 46. A vaginal contraceptive composition according to any of the above items, wherein the pH of the composition is from 2.5 to 6.5.

[0225] 47. A vaginal contraceptive composition according to any of the above items, wherein the pH of the composition is from 3.0 to 6.0.

[0226] 48. A vaginal contraceptive composition according to any of the above items, wherein the composition is a contraceptive composition.

[0227] 49. Use of a vaginal contraceptive composition according to any one of items 1 - 48 as a contraceptive agent.

[0228] 50. A vaginal contraceptive composition for therapy, wherein the vaginal contraceptive composition comprises one or more active ingredients and a physiologically acceptable gelling agent, wherein at least one of the one or more active ingredients is a mucoadhesive polymer, wherein the mucoadhesive polymer has a molecular weight between 20,000 Da and 100,000 Da, wherein the mucoadhesive polymer is composed of a plurality of monomer units connected to each other by ether bonds, ester bonds, amide bonds or combinations thereof, wherein the monomer units are selected from C6 sugars, amino-functionalized C6 sugars, amino acids or combinations thereof, and wherein at least 50% of the monomer units contain at least one amino group.

[0229] 51. A vaginal contraceptive composition for use as a contraceptive drug or agent, wherein the vaginal contraceptive composition comprises one or more active ingredients and a physiologically acceptable gelling agent, wherein at least one of the one or more active ingredients is a mucoadhesive polymer, wherein the mucoadhesive polymer has a molecular weight between 20,000 Da and 100,000 Da, wherein the mucoadhesive polymer is composed of a plurality of monomer units connected to each other by ether bonds, ester bonds, amide bonds or combinations thereof, wherein the monomer units are selected from C6 sugars, amino-functionalized C6 sugars, amino acids or combinations thereof, and wherein at least 50% of the monomer units contain at least one amino group.

[0230] 52. A vaginal contraceptive composition for fertility control or fertility control therapy, wherein the vaginal contraceptive composition comprises one or more active ingredients and a physiologically acceptable gelling agent, wherein at least one of the one or more active ingredients is a mucoadhesive polymer, wherein the mucoadhesive polymer has a molecular weight between 20,000 Da and 100,000 Da, wherein the mucoadhesive polymer is composed of a plurality of monomer units connected to each other by ether bonds, ester bonds, amide bonds or combinations thereof, wherein the monomer units are selected from C6 sugars, amino-functionalized C6 sugars, amino acids or combinations thereof, and wherein at least 50% of the monomer units contain at least one amino group.

[0231] 53. The vaginal contraceptive composition according to item 50 or 51 or 52, wherein the vaginal contraceptive composition is not a foam.

[0232] 54. The vaginal contraceptive composition according to any one of items 50 - 53, wherein the mucoadhesive polymer has a molecular weight between 20,000 Da and 90,000 Da.

[0233] 55. The vaginal contraceptive composition according to any one of items 50 - 54, wherein the mucoadhesive polymer has a molecular weight between 30,000 Da and 75,000 Da.

[0234] 56. The vaginal contraceptive composition according to any one of items 50 - 55, wherein the mucoadhesive polymer has a molecular weight between 30,000 Da and 60,000 Da.

[0235] 57. The vaginal contraceptive composition according to any one of items 50 - 56, wherein the mucoadhesive polymer has a molecular weight between 30,000 Da and 50,000 Da.

[0236] 58. The vaginal contraceptive composition according to any one of items 50 - 57, wherein the mucoadhesive polymer has a molecular weight between 30,000 Da and 40,000 Da.

[0237] 59. The vaginal contraceptive composition according to any one of items 50 - 58, wherein the mucoadhesive polymer is composed of a plurality of monomer units connected to each other by ether bonds.

[0238] 60. The vaginal contraceptive composition according to any one of items 50 - 59, wherein at least 55% of the monomer units contain at least one amino group.

[0239] 61. The vaginal contraceptive composition according to any one of items 50 - 60, wherein at least 60% of the monomer units contain at least one amino group.

[0240] 62. The vaginal contraceptive composition according to any one of items 50 - 61, wherein at least 65% of the monomer units contain at least one amino group.

[0241] 63. The vaginal contraceptive composition according to any one of items 50 - 62, wherein at least 70% of the monomer units contain at least one amino group.

[0242] 64. The vaginal contraceptive composition according to any one of items 50 - 63, wherein at least one amino group is a primary amine.

[0243] 65. The vaginal contraceptive composition according to any one of items 50 - 64, wherein the monomer units are selected from C6 sugars, amino - functionalized C6 sugars, or combinations thereof.

[0244] 66. The vaginal contraceptive composition according to any one of items 50 - 65, wherein the monomer unit is an amino - functionalized C6 sugar.

[0245] 67. The vaginal contraceptive composition according to any one of items 50 - 66, wherein the monomer unit is a combination of D - glucosamine and N - acetyl - D - glucosamine.

[0246] 68. The vaginal contraceptive composition according to item 67, wherein at least 50% is D - glucosamine.

[0247] 69. The vaginal contraceptive composition according to any one of items 67 - 68, wherein 50% or less is N - acetyl - D - glucosamine.

[0248] 70. The vaginal contraceptive composition according to any one of items 67 - 69, wherein 50% to 100% is D - glucosamine.

[0249] 71. The vaginal contraceptive composition according to any one of items 67 - 70, wherein 0% to 50% is N - acetyl - D - glucosamine.

[0250] 72. The vaginal contraceptive composition according to any one of items 67 - 71, wherein at least 65% is D - glucosamine.

[0251] 73. The vaginal contraceptive composition according to any one of items 67 - 72, wherein 35% or less is N - acetyl - D - glucosamine.

[0252] 74. The vaginal contraceptive composition according to any one of items 67 - 73, wherein 65% to 100% is D - glucosamine.

[0253] 75. The vaginal contraceptive composition according to any one of items 67 - 74, wherein 0% to 35% is N-acetyl-D-glucosamine.

[0254] 76. The vaginal contraceptive composition according to any one of items 50 - 59, wherein the mucoadhesive polymer is a peptide molecule having a length of 180 to 900 amino acids, which is linked by an amide bond.

[0255] 77. The vaginal contraceptive composition according to item 76, wherein the mucoadhesive polymer is a polypeptide of amino acids, wherein at least 50% of the amino acids are selected from the list consisting of arginine, lysine, histidine, ornithine, and β-alanine.

[0256] 78. The vaginal contraceptive composition according to any one of items 76 - 77, wherein the mucoadhesive polymer comprises polylysine, polyornithine, and / or polyarginine.

[0257] 79. The vaginal contraceptive composition according to item 78, wherein the mucoadhesive polymer comprises polylysine.

[0258] 80. The vaginal contraceptive composition according to any one of items 50 - 59, wherein the mucoadhesive polymer is a peptide molecule having a length of 180 to 900 amino acids, wherein at least 50% of the amino acids have a hydrophobic group, and the amino acids are selected from the list consisting of: alanine, methionine, cysteine, phenylalanine, leucine, valine, and isoleucine, and wherein the remaining amino acids may be selected from the list consisting of: glycine, serine, threonine, asparagine, and glutamine.

[0259] 81. The vaginal contraceptive composition according to any one of items 50 - 59, wherein the mucoadhesive polymer comprises amino acids, wherein at least 50% of the amino acids are selected from the group consisting of arginine, lysine, histidine, ornithine, and β-alanine, or 50% of the amino acids have a hydrophobic group and are selected from the group consisting of alanine, methionine, cysteine, phenylalanine, leucine, valine, and isoleucine.

[0260] 82. The vaginal contraceptive composition according to any one of items 50 - 15, wherein the mucoadhesive polymer is a peptide molecule which is linked by an amide bond, wherein at least 50% of the amino acids are selected from the list consisting of arginine, lysine, histidine, ornithine, and β-alanine.

[0261] 83. The vaginal contraceptive composition according to item 82, wherein at least 60% of the amino acids are selected from the list consisting of arginine, lysine, histidine, ornithine, and β-alanine.

[0262] 84. The vaginal contraceptive composition according to any one of items 82 - 83, wherein at least 70% of said amino acids are selected from the list consisting of arginine, lysine, histidine, ornithine, and β-alanine.

[0263] 85. The vaginal contraceptive composition according to any one of items 50 - 59, wherein said mucoadhesive polymer is a peptide molecule which is linked by amide bonds, and at least 50% of said amino acids are lysine.

[0264] 86. The vaginal contraceptive composition according to item 85, wherein at least 60%, such as at least 70% of said amino acids are lysine.

[0265] 87. The vaginal contraceptive composition according to any one of items 50 - 59, wherein said mucoadhesive polymer comprises an amino acid which is L-lysine.

[0266] 88. The vaginal contraceptive composition according to item 87, wherein said mucoadhesive polymer is poly-L-lysine (PLL).

[0267] 89. The vaginal contraceptive composition according to any one of items 50 - 88, wherein said physiologically acceptable gelling agent is selected from hydroxyethyl cellulose (HEC), glycerol, hydroxypropyl methylcellulose (HPMC), hydroxypropyl cellulose, guar gum, or a combination thereof.

[0268] 90. The vaginal contraceptive composition according to any one of items 50 - 89, wherein said mucoadhesive polymer is composed of 40 to 800 monomer units which are linked to each other by ether bonds, ester bonds, amide bonds, or a combination thereof.

[0269] 91. The vaginal contraceptive composition according to any one of items 50 - 90, wherein said mucoadhesive polymer is composed of 50 to 750 monomer units which are linked to each other by ether bonds, ester bonds, amide bonds, or a combination thereof.

[0270] 92. The vaginal contraceptive composition according to any one of items 50 - 91, wherein said mucoadhesive polymer is composed of 75 to 700 monomer units which are linked to each other by ether bonds, ester bonds, amide bonds, or a combination thereof.

[0271] 93. The vaginal contraceptive composition according to any one of items 50 - 92, wherein said mucoadhesive polymer is composed of 100 to 650 monomer units which are linked to each other by ether bonds, ester bonds, amide bonds, or a combination thereof.

[0272] 94. The vaginal contraceptive composition according to any one of items 50 - 93, wherein said mucoadhesive polymer is composed of 150 to 600 monomer units which are linked to each other by ether bonds, ester bonds, amide bonds, or a combination thereof.

[0273] 95. The vaginal contraceptive composition according to any one of Items 50 - 94, wherein the concentration of the mucoadhesive polymer is 0.05 wt.% to 10.0 wt.% of the total weight of the vaginal contraceptive composition.

[0274] 96. The vaginal contraceptive composition according to any one of Items 50 - 95, wherein the pH of the composition is 2.0 to 7.0.

[0275] 97. The vaginal contraceptive composition according to any one of Items 50 - 96, wherein the pH of the composition is 2.5 to 6.5.

[0276] 98. The vaginal contraceptive composition according to any one of Items 50 - 97, wherein the pH of the composition is 3.0 to 6.0.

Claims

1. A vaginal contraceptive composition comprising one or more active ingredients and a physiologically acceptable gelling agent, wherein at least one of the one or more active ingredients is a mucoadhesive polymer, wherein the mucoadhesive polymer has a molecular weight between 20,000 Da and 100,000 Da, wherein the mucoadhesive polymer is chitosan composed of a plurality of monomer units linked to each other, and wherein at least 50% of the monomer units contain at least one amino group.

2. The vaginal contraceptive composition according to claim 1, wherein the vaginal contraceptive composition is not a foam.

3. The vaginal contraceptive composition according to claim 1 or 2, wherein the molecular weight of the mucoadhesive polymer is from 30,000 Da to 75,000 Da.

4. The vaginal contraceptive composition according to claim 3, wherein the molecular weight of the mucoadhesive polymer is from 30,000 Da to 60,000 Da.

5. The vaginal contraceptive composition according to claim 1 or 2, wherein at least 55% of the monomer units contain at least one amino group.

6. The vaginal contraceptive composition according to claim 5, wherein at least 65% of the monomer units contain at least one amino group.

7. The vaginal contraceptive composition according to claim 1 or 2, wherein the monomer units are a combination of D-glucosamine and N-acetyl-D-glucosamine.

8. The vaginal contraceptive composition according to claim 7, wherein at least 50% is D-glucosamine and 50% or less is N-acetyl-D-glucosamine.

9. The vaginal contraceptive composition according to claim 8, wherein at least 65% is D-glucosamine and 35% or less is N-acetyl-D-glucosamine.

10. The vaginal contraceptive composition according to claim 1 or 2, wherein the physiologically acceptable gelling agent is selected from hydroxyethyl cellulose (HEC), glycerol, hydroxypropyl methyl cellulose (HPMC), hydroxypropyl cellulose, guar gum or a combination thereof.

11. The vaginal contraceptive composition according to claim 1 or 2, wherein the concentration of the mucoadhesive polymer is from 0.05 wt.% to 10.0 wt.% of the total weight of the vaginal contraceptive composition.

12. The vaginal contraceptive composition according to claim 1 or 2, wherein the pH of the composition is from 2.0 to 7.

0.

13. The vaginal contraceptive composition according to claim 12, wherein the pH of the composition is from 3.0 to 6.

0.

14. Use of the vaginal contraceptive composition defined in any one of claims 1 - 13 for the production of a contraceptive agent.

15. A vaginal contraceptive composition for use in therapy, wherein the vaginal contraceptive composition is the vaginal contraceptive composition defined in any one of claims 1 - 13.

16. A vaginal contraceptive composition for use in birth control or birth control therapy, wherein the vaginal contraceptive composition is the vaginal contraceptive composition defined in any one of claims 1 - 13.

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