Hydroalcoholic Gel Formulation and Method for Obtaining a Hydroalcoholic Gel Formulation

Description

16 Hydroalcoholic Gel Formulation and Method for Obtaining a Hydroalcoholic Gel Formulation Field of invention

[001] The present invention relates to a hydroalcoholic gel formulation with antimicrobial, anti-pilling and flame-retardant effects, for use as a hand and / or surface sanitizer. The invention also relates to a method for obtaining a hydroalcoholic gel formulation. Fundamentals of the invention

[002] Alcohol gel, or hydroalcoholic gel, is a widely used antiseptic for hand hygiene and disease prevention. At concentrations between 60 and 70%, alcohol gel eliminates most germs, bacteria, and viruses, including influenza and Covid-19 viruses (DA CRUZ, Amanda Fermiano et al. Adaptation and validation of a method for evaluating the bactericidal activity of ethyl alcohol in gel format 70%(w / w). Journal of Microbiological Methods, v. 193, p. 106402, 2022). The formula contains substances that prevent skin dryness for deep cleaning without harming the skin. Furthermore, alcohol gel is practical for use in situations where soap and water are unavailable, making it an important item for personal hygiene and public health.

[003] Hydrogel formulations containing alcohols are described in the prior art, such as in BR102018068531-7 A2, BR102020010538-8 A2 and BR102020013604-6 A2.

[004] In BR102018068531-7 A2, a moisturizing alcohol gel formulation containing the polymer carbopol 980, or cross-linked polyacrylic acid, triethanolamine, glycerin, fragrance, and dye was described. A formulation and a method for preparing hand sanitizing gel were disclosed in BR102020010538-8 A2, the formulation having in its composition a 2- to 5-carbon alcohol, conditioning agents, actives with antimicrobial / virucidal action, a sequestering agent, and a non-ionic surfactant. In BR102020013604-6 A2, an alcohol gel based on hydroxyethylcellulose (HEMC) as a gelling agent was presented. Petition 870240108975, dated 12 / 20 / 2024, page 10 / 41 / 16

[005] During the Covid-19 pandemic, there was an uncontrolled increase in the demand for hand sanitizer, causing shortages in the national market. The conventional gelling agent used in the manufacture of hand sanitizer, polyacrylic acid or carbopol, also experienced shortages in the Brazilian and global markets, as well as an abusive price increase. Compounds obtained from cellulose, such as hydroxyethylcellulose and hydroxypropylcellulose, also suffered from shortages and price increases.

[006] One of the problems with alternative gelling agents is pilling or rolling out, which is the formation of clumps from polymer residue left on surfaces, such as hands, after the alcohol evaporates. In addition, alternative gelling agents often exhibit thickener adhesion to the skin, which is undesirable for consumers.

[007] Microfibrillated cellulose (MFC), or cellulose microfibrils, is a sustainable, accessible, and widely available forest-derived product. Cellulose microfibrils do not exhibit toxicity or inflammatory effects on human macrophage cells (VARTIAINEN, Jari et al. Health and environmental safety aspects of friction grinding and spray drying of microfibrillated cellulose. Cellulose, v. 18, p. 775-786, 2011). MFC has been used in cosmetic formulations such as anti-wrinkle creams, BB creams (beauty balms), and sunscreens, showing promising results. In US2018 / 0078484A1, a BB cream formulation based on MFC was developed and tested on 20 women, with no reports of toxicity.

[008] The present invention relates to a hydroalcoholic gel formulation based on a cellulose derivative, with anti-pilling, flame-retardant and bactericidal effects. The anti-pilling effect provides a smoother and more pleasant sensation on the consumer's skin. In addition, the flame-retardant effect increases safety by reducing the risk of fires and burns. Brief description of the drawings Figure 1 shows scanning electron microscopies (SEM) for MFC produced without enzymatic pretreatment (ab) and with enzymatic pretreatment (cd). Petition 870240108975, dated 12 / 20 / 2024, page 11 / 41 / 16 Figure 2 shows a detailed drawing of the device developed to evaluate pilling (clump formation). Figure 3 shows images of the pilling tests obtained with the device shown in Figure 1. Figure 4 is a detailed drawing of the combustion chamber constructed for the self-extinguishing flame tests. Figure 5 shows images of the formulations after the burning test. Figure 6 shows the results for the pan-burning test. Figure 7 presents the results for the steam ignition test. Figure 8 shows the viscosity for different formulations with microfibrillated cellulose (MFC). Figure 9 shows the viscosity for different formulations with microfibrillated cellulose (MFC) and hydropropyl methylcellulose (HPMC). Figure 10 shows the viscosity for different formulations with microfibrillated cellulose (MFC) and poly(acrylic acid) (PAA). Figure 11 shows the viscosity for different formulations with microfibrillated cellulose (MFC), hydropropyl methyl cellulose (HPMC), and poly(acrylic acid) (PAA). Description of the invention

[009] The present invention relates to a hydroalcoholic gel formulation that has antiseptic properties, as well as greater safety for the consumer. In addition, the formulation meets the safety criteria against accidents involving alcohol-based hand sanitizers.

[0010] The term “formulation”, as used here, is interchangeable with the term “composition”. Petition 870240108975, dated 12 / 20 / 2024, page 12 / 41 / 16

[0011] In a first embodiment, the hydroalcoholic gel formulation contains ethanol, water, and gelling agents. In a preferred embodiment, the ethanol is present in a concentration ranging from 50% to 80%. In a more preferred embodiment, the gelling agents are selected from the group consisting of cellulose microfibrils, carboxymethylcellulose, carboxymethylethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, poly(acrylic acid), and combinations thereof. In a still more preferred embodiment, the gelling agents are selected from the group consisting of cellulose microfibrils, hydroxypropylmethylcellulose, poly(acrylic acid), and combinations thereof.

[0012] In a much more preferred embodiment, the gelling agents are at a concentration between 0.5% and 5.0%. In another much more preferred embodiment, the gelling agent is cellulose microfibrils with a viscosity between 2 and 14 mPa^s. Additionally, much more preferably, the cellulose microfibrils are enzymatically treated.

[0013] The hydroalcoholic gel formulation may also contain a neutralizing agent, emollient, and humectant. Neutralizing agents are bases used to adjust the pH of formulations to a pH close to neutral, whose main function is to modulate the viscosity of gelling agents and emulsify the emollient. Emollients and humectants are skin conditioning agents that help improve friction characteristics and prevent the drying effect on the skin caused by the alcohol present in the formulations.

[0014] Preferably, the neutralizing agent is selected from sodium hydroxide, potassium hydroxide, ethyl amine, diethyl amine, triethyl amine, monoethanol amine, diethanol amine, triethanol amine, and combinations thereof. More preferably, the neutralizing agent is present in a concentration ranging from 0.05% to 0.50%.

[0015] Preferably, the emollient is selected from the group consisting of sodium stearate, stearic acid, sodium laurate, potassium laurate and combinations thereof. More preferably, the emollient is present in a concentration ranging from 0.1% to 2.0%. Petition 870240108975, dated 12 / 20 / 2024, page 13 / 41 / 16

[0016] Preferably, the humectant is selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, glycerin, diglycerin, polyglycerin, urea, trehalose and combinations thereof. More preferably, the humectant is present in a concentration ranging from 0.1% to 5.0%.

[0017] The hydroalcoholic gel formulation as described has a bactericidal, anti-pilling, and flame-reducing effect. The anti-pilling effect refers to the effect of reducing the formation of lumps and / or granules on the skin after rubbing and evaporation of the ethanol.

[0018] The hydroalcoholic gel formulation as described has a viscosity of 500 to 10,000 mPa.s.

[0019] In a second embodiment, the invention relates to a method for obtaining a hydroalcoholic gel formulation comprising the following steps: (a) mixing water and neutralizing agent, under stirring; (b) first adding gelling agent to the mixture obtained in (a); (c) mixing emollient and ethanol, and optionally humectant, under heating and stirring; (d) adding the second gelling agent to the mixture obtained in (c); (e) adding the mixture obtained in (d) to the mixture obtained in (b).

[0020] More preferably, the first gelling agent of step (b) comprises cellulose microfibrils, and the second gelling agent of step (d) comprises hydroxypropyl methylcellulose, poly(acrylic acid) and combinations thereof.

[0021] Even more preferably, in step (a) the neutralizing agent is selected from sodium hydroxide, potassium hydroxide, ethyl amine, diethyl amine, triethyl amine, monoethanol amine, diethanol amine, triethanol amine and combinations thereof.

[0022] In another, even more preferred mode, in step (c), the emollient is selected from the group consisting of sodium stearate, stearic acid, sodium laurate, potassium laurate and combinations thereof, and the humectant is selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, glycerin, diglycerin, polyglycerin, urea, trehalose and combinations thereof. Petition 870240108975, dated 12 / 20 / 2024, page 14 / 41 / 16

[0023] The addition of the second gelling agent aims to prevent the agglomeration of cellulose microfibrils. Cellulose derivatives, which share the same structure as cellulose, can easily adsorb onto the surface of the MFC, resulting in the alignment of the cellulose chains of the MFC with the chains of the cellulose derivatives. This can result in reduced friction and promote sliding between chains, thus minimizing pilling, which is the entanglement of fibrils due to friction and drying of the hydroalcoholic gel that occurs when the product is applied. Therefore, the use of a second gelling agent provides the hydroalcoholic gel formulation with an anti-pilling effect. Examples of embodiments of the invention

[0024] Example 1: Production and characterization of MFC

[0025] The MFC production process is carried out by mechanical defibrillation of cellulose pulp using a Masuko Sangyo Super Masscolloider mill (Masuko, Japan), with variable flow rate and number of passes. The cellulose pulp to be used can come from different types of sources, such as hardwoods (e.g., eucalyptus) and softwoods (e.g., pine), vegetables in general, paper scraps (including corrugated, white, kraft) or recycled paper. The concentration of cellulose pulp to be processed can vary.

[0026] Table 1 presents an exemplary process for the preparation of 2 L of MFC at 1% solids content using a commercial enzyme mix.

[0027] The characterization of MFCs produced without and with the addition of enzyme was performed by scanning electron microscopy. Thus, Figure 1 shows scanning electron microscopies (SEM) for MFC produced without enzymatic pretreatment (ab) and with enzymatic pretreatment (cd). Petition 870240108975, dated 12 / 20 / 2024, page 15 / 41 / 16 Table 1. Process for preparing MFC. Raw Material Quantity Process Deionized water 2 L Charge Ammonium acetate 1.5416 g Add to water while stirring and adjust the pH to 5.5 using acetic acid, thus obtaining a buffer. Buffer 2 L Heat to 25 °C. Cellulose pulp 20 g Chop into small pieces. Buffer 2 L Load into a processor (e.g., food blender) along with the cellulose pulp and process the mixture for 1 min. Enzyme 1 mg / g of dry pulp Load into the mixture and incubate at 25 °C for 49 min. This step is optional. Mill Adjust the flow rate to 0.5 L / min. Mixture Load into the mill and subject to 15 passes, thus obtaining the MFC. MFC Heat above 80 °C for 10 min. for enzyme inactivation. Concentrate the MFC by filtration to the desired concentration (between 4 and 6%).

[0028] MFC without enzymatic pretreatment presented strongly compacted aggregates in the form of sheets (arrows 1) and thicker rods (arrows 2), which form a network structure. On the other hand, MFC with enzymatic pretreatment exhibited a less compacted and much more fibrillar structure, with more open sheet-shaped structures (arrows 3) and thinner rods (arrows 4), suggesting that the enzyme-assisted process had a strong impact on the production of well-dispersed cellulose microfibrils with smaller dimensions. This is corroborated by the viscosity. Petition 870240108975, dated 12 / 20 / 2024, page 16 / 41 / 16 intrinsic to MFCs, which is an indirect measure of molecular weight, where MFCs with and without pretreatment presented values ​​of 4.17 and 9.81 mPa^s, respectively.

[0029] Example 2: Preparation of hydroalcoholic gel formulations.

[0030] The components used to prepare the hydroalcoholic gel formulations are listed in Table 2. Table 2. Components of the hydroalcoholic gel formulation. Material Quantity (%) Ethanol 60 - 70 Stearic acid 0.25 Glycerin 1.00 Cellulose microfibrils (CMF) 0.50 - 1.30 Hydroxypropyl methylcellulose (HPMC) 0.05 - 1.00 Poly(acrylic acid) (PAA) 0.05 - 0.30 Water qsp Triethanolamine (TEA) 0.13 Total 100.00

[0031] The preparation of the formulations was carried out as follows: (a) mix water and triethanolamine, under stirring; (b) add MFC to the mixture obtained in (a) and set aside; (c) mix ethanol with stearic acid and, optionally, glycerin, under stirring and Petition 870240108975, dated 12 / 20 / 2024, page 17 / 41 / 16 heating until dissolution; (d) add HPMC and / or PAA to the mixture obtained in (c); (e) add the mixture obtained in (b) to the mixture obtained in (d), under agitation.

[0032] Example 3: Evaluation of the anti-pilling effect.

[0033] The evaluation of the anti-pilling effect (reduction in the formation of lumps or granules upon application of the product) was carried out on formulations with different components and with MFC with and without enzymatic pretreatment. For this, 0.1 mL of each formulation was used, applied in a transverse line to a sheet of EVA - poly(ethylene-co-vinyl acetate), which is affixed to the drawer of the device shown in Figure 2. A lid with an EVA affixed to its underside rests on the drawer. The device is then turned on for 15 s, during which the drawer performs a back-and-forth movement, simulating friction between the hands. Afterwards, the EVA sheets are photographed and the length of the lumps is measured using ImageJ software. The sample size used is greater than 150 and the results are expressed as mean and standard deviation. The visual results are presented in Figure 3.

[0034] Table 3 presents the pilling results. Identical superscript letters indicate that there were no statistically significant differences, according to the analysis of variance (ANOVA).

[0035] The results presented show that the use of HPMC significantly reduces the formation of clumps / granules (pilling). Thus, hydroalcoholic gel formulations with MFC and HPMC exhibit an anti-pilling effect when compared to other formulations.

[0036] Example 4: Self-extinguishing flame test Self-extinguishing flame tests were performed in a standardized combustion chamber as shown in Figure 4. Petition 870240108975, dated 12 / 20 / 2024, page 18 / 41 / 16 Table 3. Pilling test results. Sample MFC without enzyme 1% MFC 1% / MFC 1% / HPMC 0.1% / PAA 0.1% MFC with enzyme 1% / PAA 0.1% HPMC 0.1% Length (pm) 747 ±1306A 657 ±1652 A 238 ± 167 B 1224 ± 2131 C 325±221 B Length variation (pm) 90-12780 60-19140 50-1400 60-13950 30-1110

[0037] The tests were performed in triplicate, where samples were placed on metal plates 53 mm in diameter and 10 mm high. The surface of the samples was leveled using a ruler, and they were then burned. Images were recorded on video during the burning process, and the surfaces were photographed after burning. Figure 5 shows images of some formulations that exhibited flame self-extinguishing. As can be observed, a film forms on the surface of the samples, which is responsible for flame self-extinguishing, isolating the fuel from the oxidizer.

[0038] Table 4 shows some exemplary formulations with their respective burning times.

[0039] The results obtained show that depending on the co-gelling agents used as well as their proportions, the time for flame extinction may vary from a few seconds to a few minutes.

[0040] Example 5: Security tests

[0041] Safety tests of hydroalcoholic gels (alcohol gels) were carried out in accordance with the flammability testing protocol for alcohol-based hand sanitizers. Petition 870240108975, dated 12 / 20 / 2024, p. 19 / 41 / 16 of alcohol from the US Department of Transportation and the Federal Aviation Administration (CAVAGE, William M. Flammability Test of Alcohol-Based Hand Sanitizer. US Department of Transportation Federal Aviation Administration, 2010). Table 4. Results of self-extinguishing flame tests Formulations (% of gelling agents) Burning time (s) MFC 0.6 84±23 MFC 0.8 86±78 MFC 1.0 74±102 MFC 1.1 68±71 MFC 0.9 / HPMC 0.1 42±34 MFC 0.8 / HPMC 0.2 45±38 MFC 0.7 / HPMC 0.3 39±34 MFC 0.5 / HPMC 0.5 50±35 MFC 1.0 / HPMC 0.9 21±9 MFC 1.0 / HPMC 1.0 32±31 MFC 1.1 / HPMC 0.8 19±3 MFC 1.1 / HPMC 1.0 22±11 MFC 1.3 / HPMC 0.6 19±2 MFC 1.3 / HPMC 0.8 23±4 MFC 0.8 / CBP 0.2 427±103 MFC 1.0 / CBP 0.2 166±75 MFC 1.0 / CBP 0.3 272±93 MFC 0.6 / HPMC 0.4 / CBP 0.1 89±35 MFC 0.8 / HPMC 0.4 / CBP 0.1 136±82 MFC 0.9 / HPMC 0.1 - gly 101±47 MFC 0.8 / HPMC 0.2 - gly 113±49 MFC 0.7 / HPMC 0.3 - gly 170±85 MFC 0.6 / HPMC 0.4 - gly 327±92 Petition 870240108975, dated 12 / 20 / 2024, p. 20 / 41 / 16

[0042] In this trial, three exemplary formulations were selected, namely: MFC 0.9% / HPMC 0.1% at 60% ethanol, MFC 0.9% / HPMC 0.1% at 70% ethanol, and MFC 0.8% / HPMC 0.1% / PAA 0.15% at 70% ethanol. Liquid ethanol at 70% and alcohol gel with PAA at 70% were used as controls.

[0043] Figure 6 shows the results for the pan burn test, which consists of burning 60 mL of sanitizer in a 16.5 x 16.5 cm metal container.

[0044] Liquid ethanol (Fig. 6a), among all sanitizers, exhibited the most intense flames, with wide flames exceeding 50 cm in height and an extremely fast burning time (2:36 min.). Next, the sanitizer with the highest intensity was 70 °INPM alcohol gel with PAA (Fig. 6b). The flames reached approximately 45 cm in height and were slightly narrower than liquid alcohol, with a burning time of 4:40 min. The MFC / HPMC / PAA (0.8:0.1:0.15) and MFC / HPMC (0.9:0.1:0) formulations, both 70 °INPM, showed burning times of 12:45 and 7:27 min., respectively; and the maximum flame intensity had similar results, being narrow and with a height of around 30 cm. Finally, MFC / HPMC (0.9:0.1) 60 °INPM presented the smallest flames, with a height of around 18 cm and a burning time of 8:20 min.

[0045] Without being limited by any theory, the short burn time and flame intensity of liquid ethanol result from its high volatility. When ethanol is in gel form, such as 70° INPM alcohol gel with PAA, a lower flame intensity and increased burn time are observed, resulting from hydrogen bonds between the ethanol and the PAA and glycerin system, which reduces the evaporation rate (JIAN, Yukun et al. Antifreezing and Stretchable Organohydrogels as Soft Actuators. Research, v. 13, 2019). Along these lines, it can be assumed that systems with MFC and co-gelling agents, due to the large number of hydroxyl groups available, in addition to the fact that cellulose exhibits strong ethanol sorption (BOSSU et al., 2018), further decrease the evaporation rate.

[0046] In addition, the height and intensity of the flames are parameters related to heat transfer, which poses a risk to objects distant from the sources of Petition 870240108975, dated 12 / 20 / 2024, p. 21 / 41 / 16 fire. The larger the flames, the greater the heat transfer, and therefore the greater the risk of fire (GUO et al., 2023; SUN; ZHANG; HUANG, 2024). Furthermore, smaller flames are easier to extinguish (CAVAGE, 2010). Thus, it is evident that alcoholic sanitizers in gel form are safer regarding the risk of fire, especially formulations using MFC. Although the burning time is longer than liquid ethanol.

[0047] Figure 7 shows the results for the vapor ignition test, which consists of heating 60 mL of sanitizer on a heating plate at 200 °C for 3 min. A 5 L bottomless container is placed on top of the heated sanitizer to capture the vapors. In the vapor ignition test, images were captured at the moment of the explosion (images above) and after the flame stabilized (images below).

[0048] Concerning the explosion, the highest intensity was observed for liquid ethanol, followed, apparently, by MFC / HPMC / PAA (0.8:0.1:0.15). The others were very similar to each other.

[0049] After the flames stabilized, the burning intensity in descending order was: liquid ethanol > PAA > MFC / HPMC / PAA (0.8:0.1:0.15) > MFC / HPMC (0.9:0.1:0) 70 °INPM > MFC / HPMC (0.9:0.1:0) 60 °INPM.

[0050] The results obtained in the vapor ignition test were consistent with those obtained in the pan burning test, where the formulations with MFC showed greater safety. Except for MFC / HPMC / PAA (0.8:0.1:0.15), which showed a higher explosion intensity.

[0051] In fact, it can be observed that liquid ethanol represents the greatest risk of accidents and fires, followed by 70° INPM alcohol gel with PAA, with regard to the ignition of their non-volatile components. On the other hand, alcohol gels with MFC proved to be safer, with more controlled flames, less explosion due to vapor ignition, and longer burn times. Petition 870240108975, dated 12 / 20 / 2024, p. 22 / 41 / 16

[0052] Example 6: Concentration, polymer association and viscosity and use of humectant / emollient

[0053] The viscosity of the formulations depends on the concentrations of MFC and other added gelling agents (co-gelling agents) used, their combination, as well as the use of humectant / emollient.

[0054] Figures 8 to 11 show the results obtained. Figure 8 shows the viscosity gains with increasing MFC concentration. As can be observed, MFC exhibits a linear increase in viscosity as its concentration increases. The viscosity gain for each 0.1% increase is around 400 mPa^s.

[0055] Figure 9 shows the viscosities of formulations with 1.0% MFC in association with HPMC at concentrations ranging from 0.4% to 1.0%. As can be seen, there is a linear increase in viscosity, with an average gain of 870 mPa·s for each 0.1% increase in HPMC.

[0056] Figure 10 shows the viscosities of formulations with MFC at concentrations ranging from 0.6% to 1.0% and PAA at concentrations ranging from 0.0% to 0.3%. At low concentrations such as 0.1%, PAA promotes an increase in MFC viscosity of 22% to 70% depending on the MFC concentration. At higher concentrations, such as 0.3% PAA, there is an increase in viscosity greater than 800% at a concentration of 0.6% MFC.

[0057] Figure 11 shows the viscosities resulting from the combination of MFC, HPMC, and PAA, as well as the effect of using glycerin or stearic acid. MFC was used at 0.7% and 0.8%; HPMC at 0.1% and 0.15%; and PAA at 0.15%. A 0.1% increase in MFC / HPMC results in a 16% increase in the viscosity of the formulations when using stearic acid. A 0.5% increase in HPMC leads to a 13% increase in viscosity when using stearic acid. Using glycerin instead of stearic acid results in a viscosity difference ranging from 49% to 74%, depending on the concentrations of MFC and HPMC used. This effect of stearic acid on viscosity is probably due to the carboxylic groups of PAA being less ionized in its presence. Petition 870240108975, dated 12 / 20 / 2024, p. 23 / 41 / 16

[0058] Example 7: Bactericidal efficacy tests

[0059] Bactericidal efficacy assays were performed in accordance with prEN 12054. The following test strains were used: E. coli ATCC 25922, S. aureus ATCC 6538 and P. aeruginosa ATCC 27853. The test strains were cultured on tryptone soy agar (TSA) for 24 ha at 37 °C; after which, 3 to 4 colonies were transferred to a tube with sterile saline solution and their turbidity adjusted to 0.5 on the McFarland scale. In this experiment, 3 exemplary formulations were selected, namely: MFC 0.9% / HPMC 0.1% at 60% ethanol, MFC 0.9% / HPMC 0.1% at 70% ethanol, and MFC 0.8% / HPMC 0.1% / PAA 0.15% at 70% ethanol.

[0060] Furthermore, for comparison purposes, a commercial formulation based on PAA with 70% ethanol was tested. For the tests, 9 mL of each formulation were mixed with 1 mL of the bacterial suspension. After 30 s of application, 1 mL of the mixture was transferred to a tube with 9 mL of saline solution and allowed to stand for 5 min. Then, a serial dilution was performed, with 0.1 mL of each being plated on TSA using the spread plate method, incubated at 37 °C for 48 h, and the colony-forming units (CFUs) count was performed.

[0061] Bacterial reduction was calculated as the difference in viable counts before and after the application time. For compliance with prEN 12054, the minimum requirement for bactericidal activity is a 10⁵-fold reduction in 1 min.

[0062] The results were expressed as a logarithmic reduction factor, according to the equation: FR = Log N0 - Log Nx, where FR is the reduction factor, Log N0 is the initial count and Log Nx is the count after contact with the sanitizer.

[0063] The results for the Logarithmic Reduction Factor (FR) are presented in Table 5.

[0064] In accordance with prEN 12054, all formulations tested here, as well as commercial alcohol gel, exceeded a 105-fold reduction of all ATCC strains in 30 s. FR values ​​are not expressed using standard deviation. Alternatively, for greater clarity of the data, Table 6 presents the results as a power of 10. Petition 870240108975, dated 12 / 20 / 2024, page 24 / 41 / 16 Table 5. Logarithmic Reduction Factor (FR). Formulations Tested Strains E. coli S. aureus P. aeruginosa MFC / HPMC 0.9 / 0.1 - 60% EtOH 7.19 6.88 8.00 MFC / HPMC 0.9 / 0.1 - 70% EtOH 7.19 8.03 8.00 MFC / HPMC / PAA 0.8 / 0.1 / 0.15 - 70% EtOH 7.19 6.88 8.00 Commercial EtOH gel 8.00 8.03 8.00 Table 6. Results as a power of base 10. Formulations Tested Strain - E. coli No(1O6) Nx(106) R (106) R (%) MFC / HPMC 0.9 / 0.1 - 60% EtOH 15.60±1.30 0±00 15.60±1.30 99.99 MFC / HPMC 0.9 / 0.1 - 70% EtOH 15.60±1.30 0±00 15.60±1.30 99.99 MFC / HPMC / PAA 0.8 / 0.1 / 0.15 - 70% 15.60±1.30 0±00 15.60±1.30 99.99 Commercial EtOH 99.00±6.00 0±00 99.00±6.00 99.99 Formulations Tested Strain - S. aureus No(1O6) Nx(106) R (106) R (%) MFC / HPMC 0.9 / 0.1 - 60% EtOH 7.55±0.21 0 ±0 7.55±0.21 99.99 MFC / HPMC 0.9 / 0.1 - 70% EtOH 108.00±15.00 0 ±0 108.00±15.00 99.99 MFC / HPMC / PAA 0.8 / 0.1 / 0.15 - 70% 7.55±0.21 0 ±0 7.55±0.21 99.99 Commercial EtOH 108.00±15.00 0 ±0 108.00±15.00 99.99 Formulations Tested strain - P. aeruginosa No(1O6) Nx(1O6) R (1O6) R (%) MFC / HPMC 0.9 / 0.1 - 60% EtOH 101.00±20.00 0±00 101.00±20.00 99.99 MFC / HPMC 0.9 / 0.1 - 70% EtOH 101.00±20.00 0±00 101.00±20.00 99.99 MFC / HPMC / PAA 0.8 / 0.1 / 0.15 - 70% 101.00±20.00 0±00 101.00±20.00 99.99 Commercial EtOH 101.00±20.00 0±00 101.00±20.00 99.99 Note: No - initial count; Nx - count after contact with the sanitizer; R - reduction; R (%) - percentage reduction. Petition 870240108975, dated 12 / 20 / 2024, page 25 / 41

Claims

1 / 4 CLAIMS 1. HYDROALCOHOLIC GEL FORMULATION, characterized by containing ethanol, water and gelling agents.

2. A hydroalcoholic gel formulation, according to claim 1, characterized in that ethanol is present in a concentration ranging from 50% to 80%.

3. A hydroalcoholic gel formulation according to claim 1, characterized in that the gelling agents are selected from the group consisting of cellulose microfibrils, carboxymethylcellulose, carboxymethylethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, poly(acrylic acid) and combinations thereof.

4. A hydroalcoholic gel formulation according to claim 3, characterized in that the gelling agents are selected from the group consisting of cellulose microfibrils, hydroxypropyl methylcellulose, poly(acrylic acid) and combinations thereof.

5. HYDROALCOHOLIC GEL FORMULATION, according to any one of claims 3 and 4, characterized in that the gelling agents are in a concentration between 0.5% and 5.0%.

6. HYDROALCOHOLIC GEL FORMULATION, according to any one of claims 3 to 5, characterized in that the gelling agent is cellulose microfibrils with a viscosity between 2 and 14 mPa^s.

7. HYDROALCOHOLIC GEL FORMULATION, according to claim 6, characterized in that the cellulose microfibrils are enzymatically treated. Petition 870240108975, dated 12 / 20 / 2024, page 26 / 41 2 / 4 8. HYDROALCOHOLIC GEL FORMULATION, according to any one of claims 1 to 7, characterized by also containing a neutralizing, emollient and humectant agent.

9. A hydroalcoholic gel formulation according to claim 8, characterized in that the neutralizing agent is selected from sodium hydroxide, potassium hydroxide, ethyl amine, diethyl amine, triethyl amine, monoethanol amine, diethanol amine, triethanol amine, and combinations thereof.

10. A hydroalcoholic gel formulation according to claim 9, characterized in that the neutralizing agent is present in a concentration ranging from 0.05% to 0.50%.

11. A hydroalcoholic gel formulation according to claim 8, characterized in that the emollient is selected from the group consisting of sodium stearate, stearic acid, sodium laurate, potassium laurate, and combinations thereof.

12. HYDROALCOHOLIC GEL FORMULATION, according to claim 11, characterized in that the emollient is present in a concentration ranging from 0.1% to 2.0%.

13. HYDROALCOHOLIC GEL FORMULATION, according to claim 8, characterized in that the humectant is selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, glycerin, diglycerin, polyglycerin, urea, trehalose and combinations thereof.

14. HYDROALCOHOLIC GEL FORMULATION, according to claim 13, characterized in that the humectant is present in a concentration ranging from 0.1% to 5.0%. Petition 870240108975, dated 12 / 20 / 2024, page 27 / 41 3 / 4 15. HYDROALCOHOLIC GEL FORMULATION, according to any one of claims 1 to 14, characterized by having bactericidal, anti-pilling and flame-reducing effects.

16. HYDROALCOHOLIC GEL FORMULATION, according to any one of claims 1 to 15, characterized by having a viscosity of 500 to 10,000 mPa.s.

17. METHOD FOR OBTAINING A HYDROALCOHOLIC GEL FORMULATION, defined in any one of claims 1 to 16, characterized by comprising the following steps: (a) Mixing water and neutralizing agent, under stirring; (b) Adding first gelling agent to the mixture obtained in (a); (c) Mixing emollient and ethanol, and optionally humectant, under heating and stirring; (d) Adding second gelling agent to the mixture obtained in (c); (e) Adding mixture obtained in (d) to the mixture obtained in (b).

18. METHOD FOR OBTAINING A HYDROALCOHOLIC GEL FORMULATION, according to claim 17, characterized in that the first gelling agent of step (b) comprises cellulose microfibrils, and the second gelling agent of step (d) comprises hydroxypropyl-methyl-cellulose, poly(acrylic acid) and combinations thereof.

19. METHOD FOR OBTAINING A HYDROALCOHOLIC GEL FORMULATION, according to any one of claims 17 and 18, characterized in that in step (a) the neutralizing agent is selected from sodium hydroxide, potassium hydroxide, ethyl amine, diethyl amine, triethyl amine, monoethanol amine, diethanol amine, triethanol amine and combinations thereof.

20. METHOD FOR OBTAINING A HYDROALCOHOLIC GEL FORMULATION, according to any one of claims 17 to 19, characterized in that in step (c) the emollient is the group consisting of sodium stearate, stearic acid, sodium laurate, potassium laurate and combinations thereof, and the humectant is selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, glycerin, diglycerin, polyglycerin, urea, trehalose and combinations thereof. 29 / 41

Images