CA3208632A1

CA3208632A1 - Bio-based wound closure preparation

Info

Publication number: CA3208632A1
Application number: CA3208632A
Authority: CA
Inventors: Ernesto Rafael OSORIO BLANCO; Sara Schroder
Original assignee: Beiersdorf AG
Current assignee: Beiersdorf AG
Priority date: 2021-02-03
Filing date: 2022-01-12
Publication date: 2022-08-11
Also published as: DE102021200975B4; WO2022167183A1; MX2023009152A; EP4288121A1; DE102021200975A1; AU2022216364A1

Abstract

The present invention relates to a wound closure preparation made of nature-based raw materials, in particular to a sprayable bio-based wound closure preparation.

Description

Bio-based wound closure preparation The present invention relates to a wound closure preparation made from nature-based raw materials, in particular a sprayable bio-based wound closure preparation.
In particular, the invention relates to a specially composed wound closure preparation based on ethyl cellulose in combination with castor oil and glycerol.
Wound closure preparations are mostly liquid agents that are applied to a wound and close it.
The application is usually done with a spatula or brush (wound balms, wound cream, healing ointment) or in a contactless manner by spraying. The contactless application has the advantage that no additional germs get into the wound through the applicator, and large wounds, such as abrasions or burns, can be treated more quickly.
A flexible film (wound closure film) is formed from the liquid wound closure preparation after application and evaporation of the solvent contained in the wound closure preparation.
Commercial wound closure agents are, for example, Hansaplast, Wundmed, GooFix, URGO
spray plaster. They are based on acrylate systems and/or nitrocellulose.
Wound closure preparations and the wound closure films formed therefrom cover the wound without the use of other agents, and promote healing. However, wound closure films are generally not particularly resistant to mechanical stress so that abrasion of the wound closure film can occur, for example, in connection with clothing.
To prevent abrasion or the formation of tears in the wound closure film, it can therefore be advantageous to protect the wound covered with the wound closure preparation by additional measures. Wound coverings such as bandages or plasters, which offer a "mechanical"
protection, are often used for this purpose.
Furthermore, wound closure preparations can contain dispersed or crosslinkable polymers or hydrogels that form a stable film on the wound that cannot so easily be rubbed off and offers reliable protection against the ingress of dirt or microorganisms. In addition, such polymer films can be "adjusted" in such a way that water (vapor) or wound secretions can pass through. This has a positive effect on the healing success.
Film-forming, sprayable polymer solutions for producing a wound dressing (wound dressing spray) are known from DE 2343923 Al. It is a film-forming polymer solution that can be Date Recue/Date Received 2023-07-18

2 sprayed in particular from aerosol containers, which is sprayed in thin layers onto a cut, abrasion or surgical wound to be bandaged or otherwise applied after the solvent has evaporated, forming a thin, coherent film that covers the injury site.
However, the known sprayable wound closure agents only have a covering task/effect. If the wound is contaminated with microorganisms or is even an inflamed wound, a separate antiseptic treatment is required beforehand.
Antimicrobial agents have long been known to those skilled in the art.
Basically, all substances above a certain concentration have a cell-damaging effect and thus also against microbes (e.g., bacteria, fungi), i.e., they are antimicrobial. Antimicrobial agents are characterized by the fact that the cell-damaging effect on microbes is greater than on the cells of higher organisms (humans, mammals, fish, etc.).
A relatively new group of antimicrobial agents are antimicrobial peptides, what are termed AMPs. These are short amino acid chains with 3 to 5 amino acids. Such AMPs are already used in agriculture because, in contrast to classic fungicides/bactericides, they are easily degradable and do not remain to persist in the environment.
From 5E1751277 Al, SE 541313 C2, US Pat. No. 9,085,608 B2 and US Pat. No.
9,556,223 B2, the person skilled in the art is aware of AMPs for use as antimicrobial agents or for inhibiting biofilm formation.
Within the scope of the invention, the terms antimicrobial, antibiotic, and antibacterial are used synonymously. What is always meant is the specific effect against microorganisms, in particular fungi, yeasts and bacteria.
Liquid dressing materials or liquid plasters are usually sold with a propellant in aerosol containers, what are termed wound dressing sprays, from which they can be sprayed onto the wound if necessary by actuating the valve button.
However, it is also known to apply wound closure preparations with a pump sprayer, but this method of application is less uniform owing to the pump strokes than when applying as an aerosol.
Wound closure formulations based on cellulose are already known. In FR 3064488 the cellulose is present in a concentration > 6%, which is very high and expensive.
.. Very high concentrations of cellulose result in wound closure films that are very stiff and poorly adherent to the skin/wound.
Date Recue/Date Received 2023-07-18

3 The invention circumvents this disadvantage because, surprisingly, the addition of glycerol makes it possible to use a lower concentration of cellulose and thus to achieve even higher and longer-lasting adhesive strengths on the skin than with preparations of the prior art.
It was found that the addition of glycerol resulted in a synergistic effect, which resulted in the adhesive strength of the formulation becoming higher and also longer-lasting.
It was not foreseeable for the person skilled in the art - and this represents the invention -that a preparation containing ¨ at least one cellulose or a cellulose derivative, ¨ glycerin, ¨ castor oil, wherein the preparation components are dissolved in a body-compatible solvent so that the solution is low enough in viscosity to be sprayed, the problems listed above are alleviated.
According to the invention, there is also a wound closure film that is produced from the preparation and remains on the wound after the solvent has evaporated/vaporized.
The fact that a smaller amount of cellulose/cellulose derivative is sufficient can be explained by a synergistic effect, by the homogenizing effect of the glycerol in the formulation according to the invention. Due to the significantly higher homogeneous distribution of the film, the flexibility of the film increases, which can also be felt when worn on the skin. A wound closure film according to the invention adapts better to the skin, the film does not stretch as much as a film of the prior art and due to the high flexibility of the film formed according to the invention there are no tears in the film when worn on the skin/wound.
The main task of the preparation according to the invention and the wound closure film formed therefrom is reliable wound closure and optionally antiseptic properties which "clean"
the wound, i.e., kill wound germs, i.e., have a disinfecting effect and thereby promote wound healing.
The first property, "reliable wound closure", is often considered the most important property of a plaster or similar product but is not always achievable. Depending on the liquid absorption capacity of the wound dressing and/or the adhesive mass and the water vapor permeability of the product, perspiration or sweating often lead to undesired premature detachment from the skin.
Date Recue/Date Received 2023-07-18

4 According to the invention, cellulose is preferably used as the natural polymer. Celluloses with a molar mass of 100,000 to 500,000 g/mol are particularly advantageous.
Celluloses with a molar mass of 150,000 to 250,000 g/mol are advantageous.
The cellulose or the cellulose derivative surprisingly ensures that the wound secretion can be absorbed and the film can thereby be hydrated ("hydration" of the wound closure film). This allows water to "diffuse" through the wound closure film. The hydrated film can thus keep the wound moist but not wet, which can support wound healing.
For the purposes of the invention, glycerin is technical glycerin for the pharmaceutical industry and cosmetic applications. It can therefore contain the usual production-related traces of water (maximum 0.5% by weight). Tests have shown that no difference in performance can be achieved with the purest glycerol (analytical quality).
The proportion of castor oil increases the hydrophobic proportion of the formed film, which leads to increased adhesion of the film to the skin surface.
For the purposes of the invention, castor oil is understood to mean purified castor oil as permitted for cosmetic and/or medicinal purposes (density: 0.95-0.97 g/cm3;
viscosity:
approx. 1000 mPas).
It is advantageous according to the invention if the preparation also has a lower content of a second vegetable oil, in particular sunflower oil, in addition to the content of castor oil. This additional vegetable oil ensures even greater water resistance of the film formed on the skin from the preparation.
The total oil content is advantageously not higher than 20% by weight.
The film plaster system is dispersed in classic organic solvents such as ethyl acetate, alcohols and/or alkanes, which are mainly volatile.
The preparation according to the invention contains the classic organic solvents such as ethyl acetate, alcohols and/or alkanes, which are highly volatile. These solvents generally do not pose a hazard to the human body as long as they are applied topically.
When choosing solvents, a balance needs to be struck between the benefit of wound closure and the harm that a solvent might cause. Some solvents - such as ethyl alcohol or isopropyl alcohol -already have an antiseptic effect themselves, which can further increase the benefit of wound closure preparation.
Date Recue/Date Received 2023-07-18 The preparation advantageously has a viscosity in the range of up to 1500 mPas.
Commercial liquid dressing materials or liquid plasters are filled with a propellant in aerosol containers, what are termed the wound dressing sprays, from which they can be sprayed onto the wound as required by actuating the valve button. Spray plaster systems are known,

5 such as are described in patent specifications DE 2343923, DE 2924042 and B1. With the new formulation named here in combination with cellulose and/or other ingredients such as glycerin, the film can also be formed by a pump spray, which means that the use of propellants will no longer be necessary.
The system according to the invention also provides a carrier for antimicrobial agents. Active ingredients that can otherwise only be released in aqueous systems can be used in the cellulose structure, such as biodegradable active ingredients, AMP systems (antimicrobial peptides), proteins, enzymes, and biguanide systems. This is of particular interest as such active ingredients typically require aqueous systems such as hydrogels to function as an antiseptic active ingredient. These antimicrobial agents can then be used for the antiseptic treatment of wounds as well as the preservation of the preparation.
However, classic antiseptic active ingredients, in particular octenidine or its compatible salts, particularly preferably octenidine dihydrochloride, can also be used with outstanding results in the preparation according to the invention.
Active ingredients can also be added to the formulation according to the invention to covalently bind different antimicrobial components such as biodegradable active ingredients, proteins, enzymes, peptides, and/or small molecules to the polymer. These can then be used for, but not limited to, the antiseptic treatment of wounds as well as the antiseptic preservation of formulations.
Biodegradable active ingredients are mostly characterized by their positive charges. These can interact with the membrane of microorganisms through different mechanisms and often "destroy" these microorganisms. The length of the active ingredients and their flexibility play an important role here. AMPs are particularly interesting. These are sometimes more stable than proteins and enzymes to solvent and pH of the medium. In addition, AMPs are characterized by their rapid effect. In research, combinations of positively charged amino acids, such as lysine or arginine, and long, lipophilic amino acids, such as phenylalanine or tryptophan, have proven to be very effective. There is also a large number of different AMPs that consist of either short peptide sequences (2-8 amino acids) or long peptide sequences (10 to 40) and show different efficiency.
Date Recue/Date Received 2023-07-18

6 The shorter the AMP, the more important it is that it has a cationic and sterically demanding structure. Tripeptides which have shown an antimicrobial effect preferably consist of a combination of arginine, tryptophan, and/or phenylalanine and preferably have a structure with the following sequence: positively charged amino acid - hydrophobic and sterically demanding amino acid - positively charged amino acid. It is also known that modifications, for example by the attachment of protective groups, even at unusual sites, such as multiple tert-butylations on the aromatic ring of tryptophan, have a positive effect on the antimicrobial properties of such AMPs.
According to the invention, it is also conceivable to use longer peptides than AMPs for this invention. An example of this could be the palmitoyl tripeptide-3/5, which, in addition to a low antimicrobial effect, also contains the naturally occurring thrombospondin-1 (TSP-1 sequence: Pal-Lys-Val-Lys; SYNO-COLL), which in turn promotes the formation of collagen and which also supports wound healing. Longer peptides such as the RRP9W4N
from Red Glead Discovery AB also showed good antimicrobial properties and can also be used for this invention, as well as AMPs of the LL-37 families, defensin peptides and bacterial permeabilizing proteins (BPI). Longer peptides from the same amino acid can also be used for this invention, such as e-poly-L-lysine.
For example, biodegradable active ingredients, AMP systems (antimicrobial peptides), proteins or enzymes are preferably used as antiseptic active ingredients.
AMPs are particularly preferred as antimicrobial agents.
Examples The effect of the preparation according to the invention is illustrated by the following examples. In general, a template (6 cm x 2 cm) was used to be able to apply all films in the same size. To simulate the water resistance of the film on the skin, the films were applied to the forearm and washes were performed. Washing procedure: films were rubbed with soap under warm water (36 C) for 5 minutes per wash to simulate hand washing.
Table 1 shows, by way of example, three preparations from the prior art with different concentrations of ethyl cellulose and different concentrations of glycerol and castor oil.
Here and in the foregoing and below, the wt% data relate to the weight of the amounts of the ingredient used in relation to the total weight of the formulation.
Date Recue/Date Received 2023-07-18

7 Table 1 Formula Ethyl Oil Glycerin Adhesion to Flexibility Water resistance of No cellulose (wt%) wt (%) the skin (tears, the film on the skin (wt%) (hours) strained, (frequency of flexible) washing) 1 10 13 1 4 Strained 2 2 10 13 0 4 Strained 2 3* 10 13 6 ¨ ¨ ¨
4 5 5 1 3 Flexible 2 5 6.5 3 3 Flexible 2 6* 5 5 5 ¨ ¨ ¨
7 2 13 3 12 Flexible 4

8 10 13 3 48 Flexible 26

9 1.9 2.6 0.5 48 Flexible 26 2.3 3 0.7 48 Flexible 24 * Phase separation of the formulation, form was not stable enough to be applied to the skin.
It is found that only formulations with castor oil and glycerol in a defined ratio (ratio of castor oil to glycerol between 2.1 and 5; a ratio of 4.0 and 4.8 being preferred) have a surprisingly 5 positive effect on the adhesive strength of the formulation.
In addition, it was observed that formulations with ethyl cellulose in a defined ratio to glycerol (ratio of ethyl cellulose to glycerol is 3.3) in connection with the preferred ratio of castor oil and glycerol (4.8), have a further positive effect on the properties and performance of the films (e.g., example formula 8). This effect is only seen in formulations with ethyl cellulose

10 and not in formulations with for example hydroxypropyl cellulose and could be used to reduce the amounts of solids in the formulation without observing a performance loss of the film (formula 9 and formula 10).
Also the amount and type of vegetable oil is very specific for a synergistic effect (formula 11 to 13). Further experiments in which some of the oils listed below were mixed with castor oil (formula 14 to 17) also showed no improvement in film performance when the castor oil to glycerol ratio was outside of 2.1 and 5.
Table 2 shows formulations made from ethyl cellulose, a selection of different vegetable oils and glycerin, and their performance (as a film) on the skin.
Date Recue/Date Received 2023-07-18 The preparations in Table 2 are not claimed and only serve to compare the effect of the oil on the performance of the wound closure film formed.
Compared with preparations 9 and 10 in table 1, these preparations not according to the invention in Table 2 show a much poorer performance (water resistance and adhesion to the skin).
Table 2 Form I N Ethyl Oil (wt%) Glycerin Adhesion Flexibility Water cellulose in (wt%) to the skin (tears, resistance of the (wt%) (hours) strained, film on the skin flexible) (frequency of washing)

11 10 Macadamia 3 0.5 Strained 1 oil (13)

12 10 Avocado oil 3 1 Flexible 0

(13) 13 Rapeseed 3 3.2 Strained 3 oil (13)

14 10 Coconut oil 3 4 Flexible 4 (6.5) Castor oil (6.5) 10 Rapeseed 3 14 Flexible 5 oil (6.5) Castor oil (6.5) 16 10 Sunflower 3 18 Flexible 8 oil (3) Castor oil (10) 17 10 Sunflower 3 32 Flexible 20 oil (5) Castor oil (13) Date Recue/Date Received 2023-07-18 The invention addresses this problem with a specifically composed adhesive. A
first and general subject matter of the invention is an adhesive for gluing the wound:
Adhesion to the skin was determined as follows:
The films were applied to the forearm using a template (6 cm x 2 cm). How well a film adhered to the skin was determined by the time the film stayed on the skin before it came off on its own.
The water resistance was determined as follows:
The water resistance of the films was determined using washing processes. The film was subjected to laundering operations until it broke and/or separated from the skin.
Table 3 shows the excellent effectiveness of a preparation according to the invention as an aerosol with the active ingredient octenidine against various pathogens. The tests are carried out according to ISO 22196:2011 with the following microorganisms:
Staphylococcus aureus (DSM 799) Pseudomonas aeruginosa (DSM 939) Escherichia coli (DSM 1576) Enterococcus hirae (DSM 3320) Candida albicans (DSM 1386) A preparation formed the basis:
ethylcellulose (1.9%), propane/butane (50%), glycerin (0.5%), castor oil (2.6%), ethanol (45%) To compensate for the addition of octenidine, the ethanol content was always adjusted, example:
ethylcellulose (1.9%), propane/butane (50%), glycerin (0.5%), castor oil (2.6%), ethanol (44.9%), octenidine (0.1%) Date Recue/Date Received 2023-07-18 Table 3 S. aureus P. aeruginosa E. coli E. hirae C.
albicans Base formula No reduction No reduction No No No reduction Reduction Reduction Formula with 0.05% > 99.99% 95.84% > 99.99% 99.85% > 99.99%
Octenidine > log 4 log 1.38 > log 4 log 2.81 > log 4 Formula with 0.1% > 99.99% > 99.99% > 99.99% > 99.99% > 99.99%
Octenidine > log 4 > log 4 > log 4 > log 4 > log 4 Formula with 0.2% > 99.99% > 99.99% > 99.99% > 99.99% > 99.99%
Octenidine > log 4 > log 4 > log 4 > log 4 > log 4 Date Recue/Date Received 2023-07-18

Claims

1. A preparation containing ¨ 1 to 4 wt% cellulose and/or cellulose derivative, ¨ 2 to 15 wt% castor oil, ¨ 0.5 to 1.5 wt% glycerin, wherein the preparation components are dissolved in a body-compatible solvent so that the solution is low enough in viscosity to be sprayed.

2. The preparation according to claim 1, containing ¨ 1 to 4 wt% cellulose and/or cellulose derivative, ¨ 2 to 4 wt% castor oil, ¨ 0.5 to 1.5 wt% glycerin, wherein the preparation components are dissolved in a body-compatible solvent so that the solution is low enough in viscosity to be sprayed.

3. A preparation containing ¨ 1 to 4 wt% cellulose and/or cellulose derivative, ¨ 10 to 15 wt% castor oil, ¨ 3 to 7 wt% of a vegetable oil other than castor oil, ¨ 0.5 to 1.5 wt% glycerin, wherein the preparation components are dissolved in a body-compatible solvent so that the solution is low enough in viscosity to be sprayed.

4. The preparation according to claim 1, characterized in that the vegetable oil other than castor oil is sunflower oil.

5. The preparation according to at least one of the preceding claims, characterized in that the cellulose and/or cellulose derivative is exclusively ethyl cellulose.

6. The preparation according to at least one of the preceding claims, characterized in Date Recue/Date Received 2023-07-18 that the ratio of castor oil to glycerol is between 2.1 and 5; preferably from 4.3 to 4.8.

7. The preparation according to at least one of the preceding claims, characterized in that the ratio of ethyl cellulose to glycerol is 3.0 to 3.5, preferably 3.3

8. The preparation according to at least one of the preceding claims, characterized in that it contains an antiseptic agent.

9. The preparation according to at least one of the preceding claims, characterized in that the antiseptic agent is chosen from the group of bisguanidines or from the group of polyam ides.

10. The preparation according to at least one of the preceding claims, characterized in that the antiseptic agent is at least one polyhexanide.

11. The preparation according to at least one of the preceding claims, characterized in that the antiseptic agent is at least one AMP.

12. The preparation according to claim 11, characterized in that the AMP
has at least one of the amino acids from the group consisting of arginine, tryptophan and phenylalanine.

13. The preparation according to at least one of the preceding claims, characterized in that the antiseptic agent is chosen from the group of bacteria-permeabilizing proteins (BPI).

14. The preparation according to at least one of the preceding claims, characterized in that the antiseptic agent is a peptide.

15. The preparation according to claim 14, characterized in that the antiseptic active ingredient comes, for example, from the LL-37 family or from defensin peptides.

16. The preparation according to claim 14, characterized in that the peptide consists of arginine, lysine or histidine as the cationic amino acid and phenylalanine and/or tryptophan as the demanding amino acid.

17. The preparation according to claims 14 through 16, characterized in that the peptide is made up of three to thirty amino acid units, in particular has three to 5 amino acid units.

18. The preparation according to at least one of the preceding claims, characterized in that the antiseptic active ingredient is octenidine and/or octenidine hydrochloride.

19. The preparation according to at least one of the preceding claims, characterized in that the body-compatible solvent is selected from the group of alcohols.
Date Recue/Date Received 2023-07-18

20. The preparation according to claim 19, characterized in that the body-compatible solvent is ethanol.

21. The preparation according to at least one of the preceding claims, characterized in that the body-compatible solvent is ethyl acetate.

22. The preparation according to at least one of the preceding claims, characterized in that the cellulose and/or cellulose derivative has a molar mass of 150,000 to 250,000 g/mol.

23. A pump spray comprising a preparation according to at least one of the preceding claims, characterized in that it has the following contents: 2.3% ethyl cellulose, 3.2% castor oil, 0.7% glycerin, 93.8% ethyl acetate.

24. An aerosol spray comprising a preparation according to at least one of the preceding claims, characterized in that it has the following contents: 1.9% ethyl cellulose, 2.6% castor oil, 0.5% glycerin, 45% ethyl acetate dissolved in propane/butane 40/60.

25. A liquid plaster comprising a preparation according to at least one of the preceding claims, characterized in that it has the following contents: 10% ethyl cellulose, 13% castor oil, .. 5% sunflower oil, 3% glycerin, 69% ethyl acetate.

26. A wound closure film formed from a preparation according to at least one of the preceding claims, characterized in that the preparation is applied to a wound and the substance contained in the preparation has largely evaporated.
Date Recue/Date Received 2023-07-18