Process for obtaining nanofibers from a polymeric solution, nanofibers, and uses thereof

Abstract

The present invention relates to a process for obtaining nanofibers from a polymeric solution and an essential oil, having a deodorant and sweat-absorbing action. The nanofibers obtained are used as a polymeric matrix for deodorants and antiperspirants, as well as face masks, foot and hand masks, anti-acne patches, and dressings, containing antibacterial or healing active agents.

Description

[0001] PROCESS FOR OBTAINING NANOFIBERS FROM POLYMERIC SOLUTION, NANOFIBERS AND THEIR USES Field of the invention

[0001] The present invention relates to a process for obtaining nanofibers from a polymeric solution and essential oil, with deodorant and sweat-absorbing action.

[0002] The field of application of the present invention is Cosmetics and Personal Hygiene, more precisely in the area of ​​developing new materials for controlling body odor and perspiration. Fundamentals of the invention

[0003] Deodorants and antiperspirants represent a category of personal hygiene products widely used for controlling body odor and reducing perspiration. While deodorants primarily aim to neutralize odor associated with bacterial activity on the skin, antiperspirants aim to reduce the amount of sweat released by temporarily obstructing the sweat duct. Both products are frequently formulated with active ingredients, which may include antimicrobial agents, fragrances, and antiperspirant agents, aiming to provide protection against odor and / or sweat throughout the day (OLIVEIRA, ECV; SALVADOR, DS; HOLSBACK, VSS et al. Deodorants and antiperspirants: identification of new strategies and perspectives to prevent and control malodor and sweat of the body. International Journal of Dermatology. v.60(5), pp.613-619, 2021; KANLAYAVATTANAKUL, M; LOURITH, N. Body malodours and their topical treatment agents).International Journal of Cosmetic Science, v.33, p.298–311, 2011). .

[0004] Consumer demand for more effective, safe, and sustainable products has been increasing significantly in recent years. The growing popularity of natural deodorants is noteworthy; they avoid the use of controversial ingredients such as parabens, triclosan, and aluminum, in favor of naturally derived ingredients like essential oils and plant extracts (OLIVEIRA, ECV; SALVADOR, DS; HOLSBACK, VSS et al. Deodorants and antiperspirants: identification of new strategies and perspectives to prevent and control malodor and sweat of the body. International Journal of Dermatology. v.60(5), pp.613- 619, 2021). The use of essential oils in deodorants is a field of interest due to the potential antimicrobial and aromatic properties they offer.Monoterpene compounds, such as limonene, carvacrol, linalool, among others, are related to antibacterial activity, and many essential oils have been investigated for their ability to inhibit the growth of bacteria present on the skin (TEERASUMRAN, P.; VELLIOU, E.; BAI, S.; CAI, Q. Deodorants and antiperspirants: New trends in their active agents and testing methods. International Journal of Cosmetic Science. v.45, pp.426-443, 2023; KANLAYAVATTANAKUL, M; LOURITH, N. Malodoros corporals e seus agentes de tratamento topo. .

[0005] There is a growing demand for cosmetic and dermatological products that offer superior performance and safety, which drives the development and introduction of new ingredients, technologies, and / or new ways of delivering active ingredients. In this context, electrospinning proves to be an interesting technique because it is capable of producing fibers with different properties, transporting active ingredients and sustaining their release, as well as protecting them from degradation (RAHMATI, M.; MILLS, DK; URBANSKA, AM; et al. Electrospinning for tissue engineering applications. Progress in Materials Science, v.117, 2021).

[0006] Electrospinning is a technique that allows the production of fibers on a nanometric scale from an electrically charged polymer solution. Nanofibers stand out as a differentiated material because they possess a large surface area, flexibility, high mechanical performance (e.g., stiffness and tensile strength), porosity, and the ability to transport active ingredients within their structure, allowing for increased availability of the active agent to the target site. Such properties make polymeric nanofiber a potential candidate for many applications (LURAGHI, A.; PERI, F.; MORONI, L. Electrospinning for drug delivery applications: A review. Journal of Controlled Release, V.334, p. 463-484, 2021; RAHMATI, M.; MILLS, DK; URBANSKA, AM; et al. Electrospinning for tissue engineering applications. Progress in Materials Science, v.117, 2021;682-712, 2020).

[0007] Among the current applications derived from these materials, there are examples such as filtration membranes with high selectivity, coating of medical prostheses, and the development of dressings and scaffolds for tissue recovery, such as skin, cartilage, and bone. Regarding drug delivery applications, nanofibers offer opportunities as encapsulation and release systems for different active compounds, such as antibiotics, antitumor agents, proteins, and antimicrobial agents (LURAGHI, A.; PERI, F.; MORONI, L. Electrospinning for drug delivery applications: A review. Journal of Controlled Release, V.334, p. 463-484, 2021; RAHMATI, M.; MILLS, DK; URBANSKA, AM; et al. Electrospinning for tissue engineering applications. Progress in Materials Science, v.117, 2021;

[0008] The typical electrospinning apparatus configuration consists of a syringe containing a polymer solution that is placed in an infusion pump, which pushes the syringe plunger in a continuous flow. Simultaneously, as the polymer solution is pumped through the syringe, a high voltage (5-50kV) is applied to the syringe needle. This induces a charge on the surface of the droplet, which becomes electrified. When the amount of charge in the solution is large enough to reach a critical value and overcome the surface tension, the polymer solution is ejected as a jet, which is attracted towards the metal collector due to the potential difference. On the way between the needle and the collector plate, the jet undergoes a stretching process, and the solvent evaporates completely, forming nanometric and micrometric fibers that are deposited on the collector.

[0009] Currently, there are different techniques available for electrospinning, from mono-axial techniques, such as 3D electrospinning, needleless techniques, and one of the most recent, which is portable electrospinning. The portable electrospinning method, in addition to offering greater portability and ease of use, is the only one capable of performing in situ electrospinning (KEIROUZ, A., WANG, Z., REDDY, VS, et al. The History of Electrospinning: Past, Present, and Future Developments. Advanced Materials Technology, v.8(11), 2023).

[0010] Although the operating principle of electrospinning is simple, there are parameters that influence the transformation of polymer solutions into nanofibers, among which we can mention: process parameters (voltage applied in the process, polymer flow rate, collector used, distance between the needle and the collector), solution parameters (solution viscosity, polymer molecular weight, solution concentration, surface tension, conductivity) and environmental parameters (humidity, temperature) (KEIROUZ, A., WANG, Z., REDDY, VS, et al. The History of Electrospinning: Past, Present, and Future Developments. Advanced Materials Technology, v.8(11), 2023;). This demonstrates the need to achieve the appropriate balance of the technique for the success of electrospinning.

[0011] The application of electrospun nanofibers in the field of Regenerative Medicine and Tissue Engineering has been extensively studied, but their use in the cosmetic field has been little explored. Some studies point to their use in the development of facial masks, promoting greater stability of active compounds, protection, and hydration of the skin (FATHI-AZARBAYJANI, A., QUN, L., CHAN, YW; CHAN, SY Novel vitamin and gold-loaded nanofiber facial mask for topical delivery. AAPS PharmSciTech. v.11, n.3, pp.1164–1170, 2010; SMITH, D.; RENEKER, D.; KATAPHINAN, W.; DABNEY, S. Electrospun skin masks and uses thereof. European Patent EP 1 221 927 B1; 2002), but there are no reports in the literature of the use of electrospinning for the development of fibers with deodorant and / or antiperspirant action.

[0012] Over the last few decades, the development, improvement, and dissemination of products intended for deodorant and antiperspirant protection have increased considerably, but the emergence of new forms of presentation is not noticeable, remaining restricted to aerosol, roll-on, and stick (MORDOR INTELLIGENCE. North America Deodorants Market - Segmented by Product Type, Distribution Channel and Geography – Growth, Trends, and Forecast (2020–2025). Technical Report. 2019).

[0013] Currently, products capable of controlling sweat release, antiperspirants, use aluminum salts as an active ingredient. Aluminum salts act by blocking the sweat duct, thus reducing sweat release (BENOHANIAN, Antranik. Antiperspirants and Deodorants. Clinics in Dermatology. v.19, n.4, pp.398–405, 2001), and this class of ingredients is currently the most effective for sweat control. However, its use has been questioned in recent years due to the possibility of it being absorbed through the skin and accumulating in body tissues, causing diseases (DARBRE, PD Aluminium and the human breast. Morphologie. v.100, n.329, pp.65-74, 2016; GORGOGIETAS, VA; TSIALTAS, I.; SOTIRIOU, N. et al. Potential interference of aluminum chlorohydrate with estrogen receptor signaling in breast cancer cells. Journal of molecular biochemistry. v.7, n.1, pp.1-13, 2018).Reviews indicate that studies are inconclusive and that there is no scientific evidence that the use of cosmetic products containing aluminum salts can cause disease (LISZEWSKI, W.; ZAIDI, AJ; FOURNIE, E.; SCHEMAN, A. Review of aluminum, paraben, and sulfate product disclaimers on personal care products. Journal of the American Academy of Dermatology. v.87, n.5, pp.1081 – 1086, 2021; ALLAM, MF Breast cancer and deodorants / antiperspirants: A systematic review. deodorants / antiperspirants ne constitue pas un risque de cancer du sein: The use of deodorants / antiperspirants does not constitute a risk factor for breast cancer).Thus, a new material with a high capacity for sweat absorption and the ability to carry deodorant actives within its structure becomes an interesting and innovative alternative to conventional antiperspirants.

[0014] With the aim of applying them to a deodorant product, some characteristics of nanofibers are proving interesting. Since nanofibers have a very high surface area to volume ratio, they can increase the exposure of the deodorant active ingredient in the armpit, potentially providing greater deodorant efficacy. The porous microstructure has absorption capacity and, considering its application in the armpits, can act as a sweat-absorbing material. This material may have interesting applications in cases of hyperhidrosis, where there is excessive sweat production. The incorporation of essential oils, such as lemongrass oil, into the nanofiber adds functionality to the material, potentially promoting action against odor-causing bacteria, in addition to meeting the demand for the use of naturally derived active ingredients.

[0015] The search for improved performance in cosmetic products using new production and presentation techniques is constant. In this context, electrospinning proves to be an attractive and innovative technique for the development of dermatological and cosmetic products, as it allows the production of nanofibers capable of acting as a cosmetic vehicle, carrying active ingredients with potential for improved performance, in addition to protection against degradation. State of the Art

[0016] The document in the name of FADIL et al., 2021, entitled REVIEW ON ELECTROSPUN NANOFIBER-APPLIED PRODUCTS, is a review article on the electrospinning technique, and presents its possible applications, citing, among them, the cosmetic field. As examples, it mentions a work that developed a facial mask containing vitamins and collagen (not related to the invention proposed here), and the manufacture of membranes containing fragrances which, although not explicitly stated in the document, is believed to be related to applications in deodorants. The use of fragrances in deodorants, antiperspirants, and perfumes is commonplace, and the use of electrospinning to deliver active ingredients, such as fragrances, is, in a way, predictable. The document points out this functionality, but does not indicate the possibility of the material absorbing sweat or reducing the formation of bad odor.However, the aforementioned document does not mention the advantages of using electrospinning for the development of deodorants and antiperspirants, nor does it make any reference to the potential absorptive action of nanofibers, nor to their action against odor-causing bacteria. The document states that the technique can be used for fragrance delivery, limiting itself to this purpose, without pointing out any other benefit or advantage of using this material in deodorants and antiperspirants.

[0017] The document by KAMBLE et al., 2017, entitled "NANOFIBER BASED DRUG DELIVERY SYSTEMS FOR SKIN: A PROMISING THERAPEUTIC APPROACH," reviews advances in the use of electrospun nanofibers in the delivery of pharmaceutical and cosmetic drugs, such as deodorants and antiperspirants, and cites both ethylcellulose and polyvinylpyrrolidone as natural and synthetic polymers for obtaining nanofibers. However, none of the works referenced in the document relate to the purpose proposed in the present invention, since there is no mention that the electrospun membrane could absorb sweat or combat odor-causing bacteria. Furthermore, the document generally mentions the application of electrospinning in the development of cosmetics, citing deodorants and antiperspirants among them. However, it does not reference or cite works that have developed electrospun membranes for this application.

[0018] Regarding the polymers used, it is noted that the related work cites, in a generalized way, some polymers that could be used in the technique, which is expected, since electrospinning presupposes the use of polymeric solutions. However, it does not describe the benefits obtained by combining different polymers in the electrospinning process. In the present invention, two polymers of different polarities were combined and, at the concentrations used, could be solubilized in a single solvent, ethanol, which is permitted for use in cosmetics. Furthermore, the combination made it possible to develop a non-water-soluble material capable of carrying a hydrophobic ingredient, but with sufficient hydrophilicity to absorb aqueous solutions, such as sweat.

[0019] The document in the name of QOSIM et al., 2024, entitled HYDROPHILIC AND HYDROPHOBIC DRUG RELEASE FROM CORE (POLYVINYLPYRROLIDONE)-SHEATH (ETHYL CELLULOSE) PRESSURE-SPUN FIBERS, reports polyvinylpyrrolidone and ethylcellulose-based fibers produced by pressure spinning, useful for loading hydrophilic or hydrophobic drugs into controlled drug delivery systems. Furthermore, the document details the development of a core-shell type membrane for drug delivery. The polymers used are, in fact, the same as those in the present invention (EC and PVP), but differ in polymer concentration, solvent used, and technique employed. The main difference with respect to the present invention is that the material developed in the related document is intended for delivering active pharmaceutical ingredients, and its potential to absorb liquids is neither mentioned nor evaluated.The present invention has a different, and not obvious, purpose, since ethylcellulose is hydrophobic.

[0020] Nevertheless, it appears that the material developed in the related document fulfills the purpose of the research, which was to carry and release the active ingredients. However, it would not be possible for the developed polymer solution to be electrospun directly onto the skin due to the solvents used, which can be irritating to the skin.

[0021] The document by TEERASUMRAN et al., 2023, entitled "DEODORANTS AND ANTIPERSPIRANTS: NEW TRENDS IN THEIR ACTIVE AGENTS AND TESTING METHODS," presents a systematic review of recent progress in the development of new alcohol-free, paraben-free, and naturally derived antiperspirant and deodorant active ingredients. Among other things, it mentions the use of electrospun nanofibers, as well as bacterial extracts, plant extracts, essential oils, and synthetic compounds as alternatives to conventional deodorant and antiperspirant active ingredients. The document states that electrospinning can be used to produce nanofibers capable of neutralizing odor. Considering nanofibers as carriers of active ingredients, it is expected that the addition of antibacterial agents to nanofibers will enable the control of the growth of odor-causing bacteria.However, the document makes no mention of the absorptive potential of nanofibers (which is related to the material's composition), as in the present invention. Furthermore, the document cites studies evaluating essential oils with antibacterial action, but in some of these studies, the bacteria evaluated are not related to the formation of bad odor resulting from perspiration. Additionally, the article does not suggest possible alternatives to aluminum salts for sweat control.

[0022] The document by YU et al., 2012, entitled ELECTROSPUN BIPHASIC DRUG RELEASE POLYVINYLPYRROLIDONE / ETHYL CELLULOSE CORE / SHEATH NANOFIBERS, describes the production of a "core-shell" type nanofiber for drug delivery. The difference lies in the fact that the material presented in this document has the sole purpose of delivering the active ingredient, and it is neither mentioned nor expected that the material will exhibit absorptive properties. Furthermore, the related work produced a "core-shell" type nanofiber, that is, it used coaxial equipment, which allows two different solutions to be electrospun, while the present invention used the monoaxial electrospinning technique, starting from a single solution of ethylcellulose and PVP to produce the nanofiber (even with different polarities). Nevertheless, the developed material appears to fulfill the purpose of the research, which was to carry and release the active ingredient.However, there is no mention of its potential to absorb liquids, such as sweat. Furthermore, the document does not mention the possibility of performing electrospinning directly on the skin.

[0023] The document in the name of GODAKANDA et al., 2019, entitled TUNABLE DRUG RELEASE FROM BLEND POLY(VINYL PYRROLIDONE)-ETHYL CELLULOSE NANOFIBERS, presents the development of a nanofiber that can be used as a dressing, delivering an anti-inflammatory active ingredient in a sustained manner. The polymers and solvent used are the same as in the present invention, but in different concentrations. The main difference lies in the fact that the material developed in the related document is intended to deliver the anti-inflammatory active ingredient, and its potential to absorb liquids or sweat has not been investigated. The present invention has a different, and not obvious, purpose: to absorb sweat and, at the same time, control bacterial growth.

[0024] In this way, unlike the prior art, the present invention is innovative in proposing the use of nanofiber as a sweat-absorbing material, while simultaneously combating odor-causing bacteria. More than just carrying and delivering the active ingredient (essential oil), the material of our invention has the ability to absorb sweat. This characteristic is unexpected and innovative because ethylcellulose (the main polymer of the present invention) is hydrophobic, and therefore, it is not expected to have an affinity for aqueous solutions, such as sweat. This dual action of absorbing and releasing the active ingredients proves to be a major differentiating factor. Thus, our invention can act as both a deodorant and a sweat absorber. Fundamentals of the invention

[0025] The present invention relates to a process for obtaining nanofibers by means of electrospinning of a polymer solution comprising the following steps: (a) Preparation of the polymer solution; (b) Addition of active ingredients, mainly essential oil, extract and antibacterial active ingredient; preferably essential oil; and (c) Electrospinning of the polymer solution containing active ingredients, mainly essential oils, extracts, and antibacterial active ingredients.

[0026] Additionally, the present invention relates to nanofibers obtained by the previously defined process that will be used as a polymeric matrix for deodorants and antiperspirants, as well as facial masks, foot and hand masks, anti-acne fibers or dressings, containing antibacterial or healing active ingredients. Brief description of the figures

[0027] Figure 1 shows photographs of the EC / PVP Nanofiber, in a) being removed from the collector plate; and b) in situ application.

[0028] Figure 2 shows photographs of the appearance of EC+PVP nanofibers produced in the laboratory, being a) with 0% OEL; b) with 1% OEL; and c) with 5% OEL.

[0029] Figure 3 shows scanning electron microscopy of EC+PVP nanofibers with a) 0% OEL; b) 1% OEL; c) 5% OEL.

[0030] Figure 4 shows the respective histograms of nanofiber diameter distribution that were determined from the SEM micrographs shown in Figure 3.

[0031] Figure 5 shows the thermogravimetric (TGA) and derivative thermogravimetric (DTG) analysis curves of membranes (a) OEL 0%; (b) OEL 1%; (c) OEL 5%, when subjected to heating at temperatures ranging from 25 to 600ºC under a nitrogen atmosphere.

[0032] Figure 6 shows a graph of the liquid absorption performance of electrospun nanofibers.

[0033] Figure 7 shows the percentage of mass loss of the electrospun nanofibers.

[0034] Figure 8 shows the average absorbance readings of the solutions, obtained in the optical density test. Higher values ​​indicate higher concentrations of bacteria. Detailed description of the invention.

[0035] The present invention relates to a process for obtaining nanofibers by means of electrospinning a polymer solution, which has absorption capacity and bactericidal action, and can be used, but is not limited to, the absorption of sweat and control of odors resulting from perspiration. The process comprises the following steps: (a) Preparation of the polymer solution; (b) Addition of active ingredients, mainly essential oil, extract and antibacterial active ingredient; preferably essential oil selected from the group consisting of lemongrass, melaleuca, sage, lavender, citronella, mint essential oil and / or plant extract of propolis, ginger, sage, aloe vera, witch hazel, peppermint, more preferably lemongrass essential oil, and optionally melaleuca essential oil; and (c) Electrospinning of the polymer solution containing active ingredients, mainly essential oils, extracts and antibacterial active ingredients.

[0036] Different combinations and concentrations of polymers and solvents were tested (Table 1) to define the appropriate solution and process parameters for material production. The solutions were prepared as follows: the solvent was added to an Erlenmeyer flask, followed by the slow addition of the polymer or polymer combination. The solution was magnetically stirred for 12 to 24 hours until the polymer was completely solubilized. Subsequently, 3 to 5 mL of the solution was added to a syringe, and the syringe needle (0.55 mm in diameter) was electrically charged using an electrode. The polymer solution was attracted by the electrical potential difference to a copper collector covered with aluminum foil, forming nanofibers. The electrospinning parameters used for each solution are described in Table 1.

[0037] To choose the polymer solution to be used, the following parameters were considered: i) ease of electrospinning; ii) formation of continuous and visible fibers on the collector; iii) insolubility in water; iv) possibility of using less toxic solvents, aiming at an in situ application; v) amenability to be electrospun using portable electrospinning equipment. Table 1. Polymers, solvents and electrospinning parameters that were tested. - HPC: hydroxypropylcellulose; PVP: polyvinylpyrrolidone; EC: ethylcellulose; PCL: polycaprolactone; EO: essential oil;

[0038] Among the polymeric solutions tested, the one selected consisted of 10% Ethylcellulose (EC) + Polyvinylpyrrolidone (PVP) (8:2) solubilized in absolute ethanol. This choice was mainly due to the following reasons: - Polymeric combination composed mostly of non-water-soluble polymer. Aiming at future application in a humid environment (armpits), there is a need to obtain a material with hydrophobic characteristics to maintain its structural properties during use. The combination of EC, which is a hydrophobic polymer, with PVP, which is a hydrophilic polymer, in the defined proportions, facilitated the electrospinning process and formed resistant and homogeneous fibers. In the tests carried out, it was verified that a solution composed only of EC was not able to produce fibers of quality. - Possibility of using only ethanol as a solvent.Ethanol is a permitted ingredient for use in cosmetic products, allowing for electrospinning and direct application of the product to the skin. Although the technique involves complete solvent evaporation for fiber formation, there may be residual solvent at the time of application. The polymers are inert, non-toxic, and biocompatible, making them versatile excipients for both conventional formulations and new delivery systems. They form visible, uniform fibers without flaws, easily removed from the collector, as shown in a) of Figure 1. The solvent has good compatibility with a wide variety of active ingredients, such as essential oils, extracts, and antibacterial agents, making it possible to prepare homogeneous solutions suitable for the electrospinning process. Nanofibers can be produced using portable electrospinning equipment, allowing for in situ application, as shown in b) of Figure 1.

[0039] To be added to the solution, active ingredients are used that have action against bacteria present in the axillary microbiota, such as Corynebacterium, Staphylococcus, and Cutibacterium, preferably against Staphylococcus hominis and Corynebacterium xerosis. Thus, essential oils and plant extracts can be used, but are not limited to, preferably essential oils rich in monoterpene derivatives, volatile components of low molecular weight, with bactericidal and antifungal properties described in the literature (BOROTOVÁ, P.; GALOVIˇCOVÁ, L.; VUKOVIC, NL; et al. Chemical and Biological Characterization of Melaleuca alternifolia Essential Oil. Plants. v.11, n.4, p.558, 2022; KAIREY, L.; AGNEW, T.; BOWLES, EJ et al. CHOUDHARY, S.; KHAN, MA et al.Lemongrass Essential Oil Components with Antimicrobial and Anticancer Activities. Antioxidants. v.11, n.20, 2022). .

[0040] In choosing the pure essential oils to be added, the following oils were tested: lemongrass essential oil (LEO) (Cymbopogon schoenanthus) and melaleuca essential oil (MEO) (Melaleuca alternifolia).

[0041] The strains of microorganisms used were preferentially: Staphylococcus epidermidis ATCC12228, Staphylococcus hominis ATCC27844 and Corynebacterium xerosis ATCC373 because they are bacteria that are present in the armpits and are related to the generation of axillary odor (FREDRICH, E.; BARZANTNY, H.; BRUNE, I.; TAUCH, A. Daily battle against body odor: towards the activity of the axillary microbiota. DANIEL BAWDON, DIANA S. COX, DAVID ASHFORD, A. Gordon James, Gavin H. Thomas, Identification of axillary Staphylococcus sp. involved in the production of the malodorous thioalcohol 3-methyl-3-sulfonylhexan-1-ol. GOWER, KT HOLLAND.British Journal of Dermatology. V.124, n.6, 1991). .

[0042] The chemical composition of the essential oils was determined by gas chromatography coupled to mass spectrometry.

[0043] Table 2 shows the characterization of volatile compounds present in the OEL samples. Eighteen compounds were identified, with the three major components being: geraniol (57.25%), geranyl acetate (16.21%), and citral (8.55%). The literature indicates that the composition of OEL can vary considerably depending on the region where it is produced, with reports indicating that oil from Brazil contains predominantly monoterpenes, such as geraniol. This component is related to the antibacterial activity of the oil (KATIKI, LM; CHAGAS, ACS; BIZZO, HR et al. Anthelmintic activity of Cymbopogon martinii, Cymbopogon schoenanthus and Mentha piperita essential oils evaluated in four different in vitro tests, Veterinary Parasitology, v.183, n.1–2, p.103-108, 2011; BUTZGE, JC; PIVOTTO, C.; MEZZOMO, L. et al. Antifungal Properties of Essential Oils Derived from the Genus Cymbopogon: A Systematic Review. Table 2.Volatile compounds present in lemongrass essential oil (Cymbopogon schoenanthus) identified by gas chromatography coupled to mass spectrometry (GC-MS). CAS: the substance's registry number in the Chemical Abstracts Service database.

[0044] Seventeen volatile compounds were identified in the OEM, listed in Table 3. The three major components are terpinen-4-ol (45.53%), γ-terpinene (17.72%), and terpinolene (8.25%). ISO 4730:2017 (International Organization for Standardization (ISO). ISO 4730:2017(en Essential oil of Melaleuca, terpinen-4-ol type (Tea Tree oil). 3rd ed. Vernier, Geneva, Switzerland: ISO Copyright Office, 2017)) defined minimum and maximum concentrations for some components of essential oils (EOIs) to ensure the quality of this oil, with terpinen-4-ol being the primary active constituent, comprising 35% to 48% of the melaleuca oil. The oil used in this research contains the recommended concentration of this component. Terpinen-4-ol has already been associated with promising antibacterial activity against S. aureus (CORDEIRO, L.; FIGUEIREDO, P.; SOUZA, H. et al. Terpinen-4-ol as an antibacterial and antibiofilm agent against Staphylococcus aureus. International Journal of Molecular Sciences).Table 3. Volatile compounds present in tea tree essential oil (Melaleuca alternifolia) identified by gas chromatography coupled to mass spectrometry (GC-MS). CAS: the substance's registry number in the Chemical Abstracts Service database.

[0045] To evaluate the in vitro antibacterial activity of essential oils and / or plant extracts and / or active ingredients exhibiting antibacterial action against odor-causing bacteria, such as, but not limited to, *S. hominis*, *C. xerosis*, and *S. epidermidis*, primarily essential oils, Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays were performed. The MIC was evaluated using the microdilution test according to M7A6 NCCLS 2003. Ten microliters of the essential oil concentrations studied in the MIC, from which no visible growth occurred, were removed and transferred to a Petri dish with nutrient agar. The plates were incubated at 30°C for 72 hours. The lowest concentration of essential oil that remained without bacterial growth was considered the MBC. The essential oil with the lowest MIC and MB values ​​was selected for incorporation into the Ethylcellulose (EC) + Polyvinylpyrrolidone (PVP) nanofibers.

[0046] The test demonstrated that both oils are effective against the tested bacteria. The MIC values ​​obtained for lemongrass essential oil (LEO) were 1.25 μL / mL for the three tested bacteria. The MIC values ​​for melaleuca essential oil (MEO) were 20.00 μL / mL for S. epidermidis, 80.00 μL / mL for S. hominis, and 1.25 μL / mL for C. xerosis. After the bactericidal action test, it was determined that the minimum concentrations required for effective action against the tested bacteria were 5.00 μL / mL for LEO and 80.00 μL / mL for MEO.

[0047] Thus, due to presenting a lower CMI and CIB value in the tests performed, lemongrass essential oil was selected to be incorporated into Ethylcellulose (EC) + Polyvinylpyrrolidone (PVP) nanofibers.

[0048] Nanofibers with essential oil were produced following this process: a polymer solution of up to 10% ethylcellulose and polyvinylpyrrolidone in an 8:2 (w / w) ratio was prepared by solubilization in 20 mL of absolute ethanol at room temperature and left for 24 hours under magnetic stirring. After this period, 5 mL aliquots of the solution were separated, and 1%, 5%, and 10% lemongrass essential oil (LEO) were added and magnetically stirred for 20 minutes for homogenization. 3 mL of the polymer solution was added to a 5 mL syringe, and the syringe needle (0.55 mm in diameter) was electrically charged using an electrode. A flow rate of 1 to 2 mL / hour and a voltage of 9 kV were used. The polymer solution was attracted by the electrical potential difference to a collector located 7 to 12 cm away from the needle, forming the nanofibers.The electrospun samples were collected on a metal plate covered with aluminum foil to allow for subsequent analysis, but it is possible that an in situ application, i.e., directly onto the skin, could be performed.

[0049] Absolute ethanol as a solvent proved efficient for dissolving the EC+PVP combination in an 8:2 ratio, allowing the dissolution of up to 10% (w / w) of the polymeric combination. Lemongrass essential oil (LEO) was successfully incorporated into the polymeric solution at concentrations of 1% and 5%. It was not possible to solubilize 10% of the essential oil in the polymeric solution.

[0050] Thus, three solutions were electrospun: (a) 0% OEL; (b) 1% OEL; (c) 5% OEL. During the electrospinning of solutions (a) and (b), the process remained stable, and there was no need for numerous interruptions for cleaning and unclogging the needle tip, since these solutions did not solidify frequently and produced visible, continuous, smooth, and regular fibers consistently on the collector plate. Solution (c), containing 5% essential oil, however, presented considerable difficulty in the electrospinning process, even when adjustments to the parameters were tested, such as a lower flow rate and a smaller needle / collector distance. This solution was electrospun for 2 hours, and regular fibers were not formed; instead, a thin and sparse film was formed on the collector plate, indicating that the addition of 5% OEL to the polymer solution impairs the production of nanofibers.

[0051] Figure 2 depicts the appearance of EC + PVP nanofibers at 10% (w / w) with different OEL concentrations, produced using portable electrospinning equipment. Characterization of the produced nanofibers.

[0052] The morphological characteristics of isolated nanofibers, such as average diameter, pores on the fiber surface, presence of beads, and thermal stability, are properties that must be evaluated as they influence the fiber's functionality. For sample characterization, the following analyses were performed: scanning electron microscopy, thermogravimetric analysis, liquid absorption capacity, mass loss, and evaluation of antibacterial activity. Scanning Electron Microscopy (SEM)

[0053] Samples of the developed membranes were analyzed by SEM in order to understand the morphology and distribution of the obtained fibers, their diameter, their variation, and the presence of defects and beads.

[0054] The assay was performed using a scanning electron microscope. The sample was fixed to aluminum strips using double-sided carbon adhesive tape and then coated with a layer of gold using a K450 sputter coater. The average fiber diameters were measured by image analysis using ImageJ software. The average fiber diameter was determined by performing 100 random measurements from different regions of the sample. Statistical evaluation of fiber diameter variation was performed using one-way analysis of variance (ANOVA), followed by Tukey's test, using Jamovi software. Results with p < 0.05 were considered statistically significant.

[0055] The morphology of the three membranes produced, (a) OEL 0%; (b) OEL 1%; (c) OEL 5%, was analyzed by SEM. Figure 3 shows the images obtained confirming the formation of nanofibrous membranes containing continuous, thin, and cylindrical structures for samples (a) and (b). The presence of a few defects such as beads / granules can be observed in membrane (b). This event has already been described in the literature and is undesirable because the beads can affect the uniformity and quality of the nanofibers and retain portions of the active ingredient. This event can occur due to the decrease in conductivity and surface tension of the polymer solution (FONG, H.; CHUN, I.; RENEKER, DH Beaded nanofibers formed during electrospinning. Polymer. v.40, n.16, pp.4585-4592, 1999; RAMAKRISHNA, S.; FUJIHARA, K.; TEO, W.; LIM, T.; MA, Z. Electrospinning Process. In: An Introduction to Electrospinning and Nanofibers; World Scientific: Singapore, v.3, p.(90-154, 2005), and it is possible to solve this problem by adjusting the electrospinning parameters, adding another polymer to the solution, or altering the polymer concentration of the solution (THOMPSON, CJ; CHASE, GG; YARIN, AL; RENEKER, DH Effects of parameters on nanofiber diameter determined from electrospinning model. Polymer. v.48, n.23, pp. 6913– 6922, 2007).

[0056] The micrograph of the sample with 5% OEL, shown in c) of Figure 3, indicates a coalescence of the fibers, with thick, irregular structures, granule formation, and a large variation in diameter, reinforcing the suspicion that the addition of 5% OEL alters the solution parameters and the electrospinning process, impairing the formation of nanofibers.

[0057] This can occur due to changes in the solvent evaporation rate in situations containing a higher amount of EO. In this case, the distance between the needle and the collector was probably too small to allow complete solvent evaporation. If the fibers are still wet when they reach the collector, they inevitably coalesce. Another hypothesis is that the addition of EO alters the surface tension of the solution, which is a factor that also impacts the electrospinning process and, consequently, the formation of fibers (MAVER, T., KUREČIČ, M., PIVEC, T. et al. Needleless electrospun carboxymethyl cellulose / polyethylene oxide mats with medicinal plant extracts for advanced wound care applications. Cellulose.v.27, p.4487–4508, 2020). Figure 4 shows the histograms of fiber diameter distribution that were determined from SEM micrographs. It can be seen that the incorporation of 1% OEL did not affect the fiber diameter when compared to fibers without OEL.The average diameters of EC / PVP nanofibers with 0% OEL and 1% OEL were between 262 and 436 nm, preferably 349 nm, and between 263 and 433 nm, preferably 348 nm, respectively. The fiber with 5% OEL, however, presented a quite irregular structure, with an average diameter of 761 ± 278 nm.

[0058] Statistical analysis confirms that there is no significant difference between the diameters of 0% and 1% OEL fibers, indicating that it is possible to incorporate 1% OEL into EC / PVP nanofibers without harming the fiber morphology. However, it was found that the addition of higher OEL concentrations, such as 5%, can impair the formation and structure of the nanofiber. Thermogravimetric Analysis (TGA)

[0059] Thermogravimetric analysis is defined as a continuous process that involves measuring the change in mass of a sample as a function of temperature, or time at a constant temperature. The technique was used to verify the thermal stability of the fibers.

[0060] The fiber sample was removed from the aluminum foil using a metal microspatula and metal tweezers. It was then transferred to alumina crucibles (70 µL) and these were placed in the equipment for analysis. A Thermogravimetric Analyzer was used. TGA curves were obtained with a heating rate of 10°C / min, under an inert nitrogen atmosphere, in the range of 25 to 600°C.

[0061] The thermogravimetric analysis (TGA) and derivative thermogravimetric analysis (DTG) curves of membranes (a) OEL 0%; (b) OEL 1%; (c) OEL 5%, when subjected to heating at temperatures ranging from 25 to 600ºC under a nitrogen atmosphere are shown in Figure 5.

[0062] As illustrated in Figure 5, the result of this analysis shows three stages of degradation for the sample without OEL (a), and four stages of degradation for the samples with OEL (b) and (c). The first stage, almost imperceptible, and common to all three samples, occurs between 32 and 35ºC, and must be related to the volatilization of residual ethanol from the fibers, since mass loss also occurred for the sample without OE. There is a degradation stage present only in the nanofibers containing OEL, in the temperature range between 100-140ºC, which may be related to the loss of OEL, since this peak is not present in sample (a). It is described that the volatilization temperature of OEL begins at room temperature and ends around 164ºC (MARTINS MARTINEZ, P.; SBAITE, P.; BENITES, C.; MACIEL, M. Thermal Characterization of Orange, Lemongrass and Basil Essential Oils. Chemical Engineering Transactions. v.24, pp.463-468, 2011), therefore it is possible that the polymeric nanostructure, forming interconnected and continuous networks, trapped the OEL, protecting it from volatilization and degradation at lower temperatures. Finally, two peaks appear in the three samples at higher temperatures, one at approximately 360ºC and another at 430ºC. At these temperatures, a large mass loss occurs, which is related to the degradation of the polymers.

[0063] Thus, it was verified that the EC / PVP nanofiber possesses good thermal stability, and its degradation occurs at a temperature well above the expected operating temperature of the material. Absorption capacity

[0064] The absorption capacity of the fibers was determined in vitro using a synthetic sweat solution. The synthetic sweat was prepared according to ISO 105-E04:2014 (ABNT. NBR ISO 105-E04: Textiles - Color fastness tests - Part E04: Color fastness to sweat. Rio de Janeiro: ABNT, 2014). Nanofiber samples measuring 3.0 cm² were initially weighed to determine the dry mass. They were then immersed in 40 mL of synthetic sweat solution and stored at 37 ± 0.1°C, simulating body temperature, for 24 hours. After this period, the samples were removed from the solution and weighed again. The test was performed in triplicate and the liquid absorption capacity (A) was calculated according to Eq. (1), where Mu is the mass of the wet sample and Ms is the mass of the dry sample. ^ (%) = (^^ ^^ −^^ ^^ ) ^^ ^^ ^^ 100 Eq. (1)

[0065] The results of the experiments were expressed as mean ± standard deviation. Statistical evaluation of the data was performed using one-way analysis of variance (ANOVA), followed by Tukey's test. Results with p < 0.05 were considered statistically significant.

[0066] The absorption of synthetic sweat, evaluated under simulated physiological conditions at a temperature between 35 and 39°C, preferably 37°C, and a pH between 4 and 7, preferably 5.5, reached an average of 464% by weight (m / m) for the nanofiber without OEL and 551% for the nanofiber containing 1% OEL (Figure 6). There is no statistical difference between the formulations. The test demonstrates the sweat absorption capacity of the produced fibers, which is extremely relevant considering the proposed use of this material. Furthermore, it was verified that the incorporation of OEL into the fiber does not decrease the absorption rate of the membrane, allowing the application of active ingredients to the nanofiber without compromising its absorptive properties. Mass loss

[0067] In vitro mass loss percentage tests allow verification of the potential for degradation, which is related to the degree of hydration of the system and is important to verify if the material exhibits structural stability during the active ingredient release period (VAN DEN MOOTER, G.; SAMYN, C.; KINGET, R. Characterization of colon-specific azo polymers: A study of the swelling properties and the permeability of isolated polymer films. International Journal of Pharmaceuticals). The analysis played an important role in the research because it allowed us to assess whether the material's structure is able to remain stable under simulated use conditions.

[0068] The in vitro mass loss study was performed in a petri dish containing synthetic sweat, which was prepared according to ISO 105-E04:2014 (ABNT. NBR ISO 105-E04: Textiles - Color fastness tests - Part E04: Color fastness to sweat. Rio de Janeiro: ABNT, 2014). Samples with known weights were placed in the dish containing 40 mL of synthetic sweat and kept at 37 ± 0.1°C for 24 hours. After this period, the samples were removed, washed with 10 mL of distilled water and dried at room temperature for 24 hours. The test was performed in triplicate and the mass loss (M) was calculated using Eq. (2), where Mi is the initial weight and Mf is the final weight: 100 Eq. (2)

[0069] The results of the experiments were expressed as mean ± standard deviation. Statistical evaluation of the data was performed using one-way analysis of variance (ANOVA), followed by Tukey's test. Results with p < 0.05 were considered statistically significant.

[0070] The percentage of mass loss is shown in Figure 7. There was a mass loss of approximately 12% in the nanofiber without OEL and 13% in the nanofiber with 1% OEL, and there is no statistical difference between the samples (n = 3, Tukey test, p < 0.05). The mass loss was expected, since PVP is a water-soluble polymer and synthetic sweat contains mostly water in its composition. However, it was found that the nanofiber structure was not compromised, since ethylcellulose was used in greater quantity for the production of the nanofibers. These results indicate that the material could be used in humid environments, such as armpits, without considerable compromise to its structure, maintaining its absorbent properties. Antibacterial activity of nanofibers

[0071] To evaluate the in vitro antibacterial activity of the nanofibers, an optical density test was performed. This method is based on measuring the turbidity or opacity of a bacterial solution. Absorbance is measured using a spectrophotometer, which quantifies the amount of light absorbed by the solution at a given wavelength. Thus, it is possible to infer that the higher the optical density (or absorbance), the higher the concentration of bacteria in the solution.

[0072] The test was performed with the bacterial strains Staphylococcus epidermidis ATCC12228 and Staphylococcus hominis ATCC27844, as these species are present in the axillary microbiota. The procedure was performed in a laminar flow hood, and all materials used, except for the nanofibers, were sterilized at 121ºC for 15 minutes, followed by ultraviolet radiation for 30 minutes before starting the experiment. The experiment used two 12-well plates, with one plate used for each bacterium tested.

[0073] Samples of 2.0 cm² of nanofiber were incubated in 0.2 mL of bacterial suspension (concentration: 10⁷ CFU / mL) and 1.8 mL of Nutrient Broth culture medium containing 5% Tween 80 for 48 hours at 37°C. After this period, the absorbance of each well of the plate was measured using a Spectrostar Nano spectrophotometer at a wavelength of 625 nm. The culture medium with added Tween 80 was used as a blank, and the culture medium, Tween 80, and bacterial inoculum were used as a positive control. In each plate, 3 wells were used for analysis of nanofiber without essential oil (EO), 3 wells for nanofibers with 1% EO, 2 wells containing the blank control, and 1 well containing the positive control.

[0074] Spectrophotometric absorption readings were conducted for the following samples: blank control, positive control, nanofiber with 1% OEL, and nanofiber without OEL. The values ​​obtained in the positive control samples and in the nanofibers were corrected by subtracting the average of the values ​​obtained in the reading of the blank sample. Subsequently, these corrected results were compared for each bacterium tested. This approach allows us to evaluate the impact of nanofibers with and without OEL on inhibiting bacterial growth compared to the positive control, providing important information about the potential of these materials to act as antimicrobial agents.

[0075] The axillary microbiota plays an important role in the generation of odor-causing compounds. It is described that the resident flora in the human axilla is mainly composed of Corynebacterium, Staphylococcus, and Cutibacterium, with some species, such as S. hominis and C. xerosis, being able to metabolize odorless compounds present in sweat, generating malodorous compounds (FREDRICH, E.; BARZANTNY, H.; BRUNE, I.; TAUCH, A. Daily battle against body odor: towards the activity of the axillary microbiota. Trends in Microbiology. v.21, n.6, pp. 305-312, 2013; MINHAS, GS; BAWDON, D.; HERMAN, R. et al. Structural basis of malodour precursor transport in the human axilla. ELife, 7:e34995, 2018; DANIEL BAWDON, DIANA S. COX, DAVID ASHFORD, A. Gordon James, Gavin H. Thomas, Identification of axillary Staphylococcus sp. involved in the production of the malodorous thioalcohol 3-methyl-3-sufanylhexan-1-ol. HOLLAND.In vitro and in-vivo studies of human axillary odor and the cutaneous microflora. British Journal of Dermatology. V.124, n.6, 1991) .

[0076] Human underarm odor is composed of a mixture of volatile organic compounds, such as volatile fatty acids and thioalcohols. Thioalcohols, despite being present in small quantities, are the most pungent volatiles. S. hominis has been identified as a bacterium capable of producing 3-methyl-3-sulfanyl-hexan-1-ol (3M3SH), which is one of the main components of body odor in qualitative terms (RUDDEN, M.; HERMAN, R.; ROSE, M. et al. The molecular basis of thioalcohol production in human body odor. Science Report. vol. 10 (12500). 2020).

[0077] Staphylococcus epidermidis is an abundant bacterium on the skin, and has recently been recognized as an important bacterium for maintaining skin health. Its presence contributes to the balance of the microbiota and helps strengthen the skin barrier and defenses against pathogens (EISENSTEIN, M. The skin microbiome. Nature. v. 588, n.209, 2020). Studies indicate that in cases of atopic dermatitis and sensitive skin, there is a decrease in S. epidermidis in the cutaneous microbiota (ZHENG, Y.; LIANG, H.; LI, Z. et al. Skin microbiome in sensitive skin: The decrease of Staphylococcus epidermidis seems to be related to female lactic acid sting test sensitive skin. Journal of Dermatological Science. v. 97, n.3, pp. 225-228, 2020; BYRD, AL; DEMING, C.; CASSIDY, SKB et al.).Furthermore, even though it is present in large quantities in the skin of the armpits, it does not appear to be related to the formation of odor-causing compounds (RUDDEN, M.; HERMAN, R.; ROSE, M. et al. The molecular basis of thioalcohol production in human body odor. Science Report. vol. 10 (12500). 2020).

[0078] Thus, the research sought a bacterial control method targeting S. hominis bacteria, with minimal impact on S. epidermidis, aiming for a bacterial control focused on the species responsible for the formation of the bad odor.

[0079] The optical density test was used to evaluate the antibacterial potential of the nanofiber samples. Figure 8 shows the average absorbance values ​​obtained in the test after 48 hours of incubation of the nanofibers with bacterial inocula at 37°C. The higher the absorbance value, the higher the bacterial concentration in the solution. The test indicated that the nanofiber containing OEL showed, on average, greater antibacterial activity against S. hominis, a bacterium capable of forming 3M3SH. Similar absorbance values ​​were also obtained for S. epidermidis; however, in this case, this behavior is interesting, given that the bacterium plays an important role in the axillary microbiota and is not related to the formation of bad odor.

[0080] The test showed a reduction in the growth of S. hominis after contact with the nanofiber containing OEL versus the nanofiber without OE and the positive control, and considering that this bacterium is important in the development pathway of 3M3SH, controlling its growth could have a considerable impact on body odor.

[0081] Thus, electrospinning proves to be an interesting technique and an effective strategy for preserving the properties of active ingredients, potentially serving biomedical, pharmaceutical, or cosmetic purposes. In the cosmetic and dermatological field, nanofibers present themselves as an innovative and versatile material, capable of delivering active ingredients with different purposes, such as antioxidant, moisturizing, healing, and anti-inflammatory properties, among others. The three-dimensional structure, with a high surface area, allowing for prolonged release of the ingredient to the skin, and protection against degradation are the main advantages compared to other conventional cosmetic forms.

[0082] The present invention demonstrates that it is possible to develop an ethylcellulose and polyvinylpyrrolidone nanofiber containing lemongrass essential oil in its structure, for deodorant application. The developed fiber exhibits absorbent activity, being able to retain more than 500% of its weight in synthetic sweat, showing applicability for the intended function, being quite interesting in cases of hyperhidrosis, where there is excessive sweat production. Furthermore, the polymeric matrix did not show significant alterations after 24 hours in contact with synthetic sweat, losing 0 to 20%, preferably 10-15%, more preferably 13% of its initial mass, maintaining its conformation and membranous aspect. Thermal stability proved adequate, considering the expected usage temperature for this type of material, in addition to providing protection of the essential oil against degradation and / or volatilization. The action against S.Hominis, a bacterium capable of synthesizing odor-causing compounds, shows promising potential for application as a novel deodorant.

Claims

1. 1 / 3 CLAIMS 1. Process for obtaining nanofibers characterized by the fact that it comprises the following steps: (a) Preparation of the polymer solution; (b) Addition of active ingredients, mainly essential oil, extract and antibacterial active ingredient; preferably essential oil; and (c) Electrospinning of the polymer solution containing essential oil; - wherein the polymer solution comprises 8% to 10%, preferably 10% of Ethylcellulose (EC) + Polyvinylpyrrolidone (PVP) in an 8:2 ratio solubilized in absolute ethanol; and - wherein the active ingredient comprises plant extracts, mainly essential oil of lemongrass, tea tree, sage, lavender, citronella, mint and / or plant extract of propolis, ginger, sage, aloe vera, witch hazel, peppermint, preferably comprising lemongrass essential oil, and optionally tea tree essential oil, at concentrations of 1% and 5%, preferably 1%. 2.Process according to claim 1, characterized in that the lemongrass essential oil has a minimum inhibitory concentration of 1.25 μL / mL and a minimum bactericidal concentration of 5.00 μL / mL against S. hominis.

3. Process according to claim 1, characterized in that the electrospinning is carried out in... 2 / 3 conventional or portable electrospinning equipment, using a flow rate of 1 to 2 mL / hour, a voltage of 9 kV, and attracting the polymer solution by electrical potential difference to a collector at a distance of 7 to 12 cm from the needle, the polymer in the form of nanofibers being collected on a metal plate or directly on the skin.

4. Nanofibers characterized by being obtained according to the process described in claims 1 to 3 and comprising a polymer solution of 8% to 10%, preferably 10% Ethylcellulose (EC) + Polyvinylpyrrolidone (PVP) in an 8:2 ratio solubilized in absolute ethanol and preferably 1% lemongrass essential oil.

5. Nanofibers, according to claim 4, characterized by having an average diameter between 263 and 433 nm, preferably 348 nm.

6. Nanofibers, according to claim 4, characterized in that they exhibit degradation stages between 32°C and 430°C. 7.Nanofibers, according to claim 4, characterized in that they have the ability to absorb synthetic sweat, where the following physiological conditions are considered: temperature between 35 and 39 °C, preferably 37 °C, at pH between 4 and 7, preferably 8. Nanofibers, according to claim 4, characterized in that they have from 0 to 20%... 3 / 3 preferably 10-15%, more preferably 13% mass loss using synthetic sweat, where the following physiological conditions are considered: temperature between 35 and 39 °C, preferably 37 °C, at pH between 4 and 7, preferably 5.

5.

9. Use of nanofibers according to claims 4 to 8, characterized by being a polymeric matrix for deodorants and antiperspirants.

10. Use, according to claim 9, characterized by being also for facial masks, foot and hand masks, anti-acne fiber or dressings, containing antibacterial or healing actives.

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