Biodegradable polymeric micro- and nano-particles and use thereof

Abstract

The present invention pertains to the fields of biotechnology and chemistry, specifically to the field of cosmetic formulations, and involves biodegradable polymeric micro- and nano-particles, with or without encapsulated photoprotective agents, and the use of such particles as sunscreens or sun protection enhancers in sunscreen formulations. A number of health experts emphasise the importance of regular use of sunscreen. However, many of these compounds have been found to be carcinogenic and to soak into the skin, entering the body after a certain period of contact. Thus, the present invention mitigates systemic absorption, reduces the deleterious effects associated with long-term use of such photoprotectors and increases the stability of photoprotective compounds, enhancing the photoprotective action, since they combine the chemical protection of the active ingredients with the physical reflectance action of the particles. It also involves a significant environmental advantage, as it is a biodegradable matrix derived from a renewable source with low environmental impact.

Description

BIODEGRADABLE POLYMERIC MICRO AND NANOPARTICLES AND THEIR USE FIELD OF APPLICATION

[0001] The present invention is related to the areas of biotechnology and chemistry, specifically to the areas of cosmetic formulations and polymeric materials, and deals with a class of micro and nanoparticles, produced from biodegradable polymers and which may contain photoprotective actives, applied as sunscreens or sun protection intensifiers in sunscreen formulations. BACKGROUND OF THE INVENTION

[0002] The sunscreen formulations available to consumers are prepared by combining two main components: vehicles and sunscreens (active ingredients).

[0003] Sunscreens are classified as organic or inorganic.

[0004] Organic filters are capable of absorbing UV radiation and transforming it into less harmful radiation through conformational changes in their molecules, emitting radiation with longer wavelengths in the visible light range or releasing energy in the form of heat (FLOR et al, 2007; MANAIA et al, 2013). Inorganic filters, in turn, act primarily through the scattering, reflection, and / or absorption of UV rays that reach the skin's surface. These materials are usually used in particulate form, with dimensions similar to the wavelength of the incident radiation, to achieve maximum scattering (Flor et al, 2007).

[0005] Several health experts emphasize the importance of regularly using active ingredients that protect against sunlight. However, many of these compounds have allergenic and / or carcinogenic effects and permeate the skin, reaching the body after a certain period of contact.

[0006] In this context, one solution being studied to mitigate the harmful effects of these substances and their potential health risks (such as irritation, allergies, and the penetration of these components into the deeper layers of the skin), while preserving their protective action against solar rays, is the use of polymeric particles with potentially synergistic reflectance, intensifying the photoprotective effect of certain cosmetic formulations. These polymeric matrices can also be used to encapsulate photoprotective compounds. Encapsulating photoprotective active ingredients reduces or even prevents contact between these compounds and human tissue, thus mitigating several harmful effects associated with sunscreen use.

[0007] Although polymeric materials are often used as matrices for encapsulating active ingredients, most studies employ non-biodegradable synthetic polymeric materials for this purpose. Although they mitigate the harmful health effects associated with the use of free photoprotective active ingredients, the use of such materials is not advantageous from an environmental perspective, as they continue to cause accumulation of microplastics in nature and bioaccumulation effects of plastic materials throughout the food chain.

[0008] Based on the aforementioned problems, the present invention presents biodegradable polymeric micro and nanoparticles, containing or not encapsulated photoprotective actives, for use as sunscreens or sunscreen intensifiers in sunscreen formulations.

[0009] The process of encapsulating photoprotective compounds in biodegradable polymeric micro and nanoparticles not only mitigates systemic absorption and reduces the harmful effects associated with long-term use of such products, but also increases the stability of photoprotective compounds, enhancing their photoprotective action, as they combine the chemical protection of the active ingredients with the physical reflectance of the particles. Furthermore, it offers a significant environmental advantage, as it is a biodegradable matrix, derived from a renewable source, and has a low environmental impact. STATE OF THE TECHNIQUE

[0010] Brazilian document BR112020000940-7 describes a sunscreen formulation that includes a multistage polymeric particle designed to increase the Sun Protection Factor (SPF). The addition of the polymeric particle aims to enhance UV protection in sunscreens. The polymeric particle composition involves several types of monomers, including monomers that make up the core, inner shell, and outer shell. The average particle size, when dry, ranges from 50 to 1,000 nm, suggesting the use of nanoparticles. The document suggests the use of polyester as a film-forming agent.

[0011] The present invention, however, differs in that it produces particles based on polymers of renewable and biodegradable origin, including polymeric materials based on starch and succinates. The aforementioned document protects a sunscreen formulation containing particles based on acrylic and methacrylic acid, i.e., monomers of non-renewable origin that produce polymers that are not biodegradable. Furthermore, the present invention also involves the production of biodegradable particles containing encapsulated photoprotective active ingredients.

[0012] Document PI0517930-0 discloses an additive for sunscreen preparations aimed at improving sunscreen efficacy and mitigating problems associated with the prior art. One of the issues mentioned is irritation or toxicity caused by UV radiation absorbing agents used in conventional sunscreens. The document discloses the use of empty polymeric particles produced by emulsion polymerization of unsaturated monomers, along with reactive monomers. It is highlighted that such polymeric particles can increase UV radiation absorption, resulting in an increase in the sunscreen's photoprotection factor. Furthermore, the polymeric particles contain chromophores covalently bound to the polymer, which also allows them to absorb UV radiation. It is discussed that the particles can be used to increase sun protection, improve skin texture, and act as viscosity adjusting agents.

[0013] The present invention, however, proposes the use of micro and nanoparticles composed of biodegradable polymeric materials, based on starch and succinates, produced using monomers of renewable origin. Furthermore, such particles can contain encapsulated photoprotective actives, in order to intensify the photoprotection factor presented by the particles, eliminating the need for chromophores to increase sun protection.

[0014] US5932194 presents a sunscreen designed to provide long-lasting protection against ultraviolet (UV) rays, especially under conditions of water exposure. A feature of this invention is the use of non-film-forming polymers in particle form in its formulation. The polymers are used in the formulation to maintain the sunscreen's active properties even when the skin comes into contact with water. These polymers are designed to adhere to the skin and form a barrier that resists removal by water. Furthermore, the invention incorporates emulsifying and thickening agents that improve the stability of the formulation, ensuring that the active components of the sunscreen remain evenly distributed. The use of nanoparticles in the formula helps achieve broad-spectrum protection against UVA and UVB rays.

[0015] The present invention, however, differs from the previous document in that it presents micro and nanoparticles based on biodegradable polymeric matrices, employing starch and polyesters of the succinate class, to guarantee or intensify the sunscreen factor, mitigating the harmful effects associated with the use of free photoprotective active ingredients. Furthermore, the particles of the present invention may contain encapsulated photoprotective active ingredients. It is important to emphasize that, unlike the previously cited invention, which uses non-biodegradable matrices that generate microplastics, the present invention involves the use of sustainable polymeric matrices with low environmental impact.

[0016] The doctoral thesis, entitled "DEVELOPMENT OF A PHOTOPROTECTIVE FORMULATION CONTAINING POLYMERIC NANOPARTICLES WITH SUNSCREEN," aims to create cosmetic sunscreen formulations containing sunscreen nanoparticles (benzophenone-3 (BZ3), avobenzone (AVO), and methylbenzylidene camphor (MBC)) to increase the effectiveness, safety, and quality of these products. The nanoparticles are obtained using the miniemulsion polymerization technique, with the sunscreens encapsulated in situ, that is, during the polymerization process. The process results in nanoparticles with dimensions greater than 100 nm, in which the incorporated active ingredients do not interact with the reaction system and remain dispersed in the polymer matrix. The goal is to use these particles as raw materials in the manufacture of high-quality photoprotective formulations.The specific objectives include encapsulating sunscreens in polymeric resins, characterizing the resulting nanoparticles, and developing photoprotective formulations containing these nanoparticles. The research also includes in vitro and in vivo assays to evaluate the safety and efficacy of the final products.

[0017] The present invention, however, differs from the previous document in that it produces biodegradable polymeric micro and nanoparticles of renewable origin. These particles are composed of starch or polysuccinates, rather than methacrylate-type polymers, which are non-biodegradable and fossil-based polymers that result in microplastics with a high potential for bioaccumulation. Starch- and succinate-based materials are biodegradable, their degradation products are non-toxic, and they have no potential for bioaccumulation in the marine environment, thus being considered to have low environmental impact.

[0018] Korean document KR 20180024903 addresses the dispersion and stabilization of organic sunscreen agents against ultraviolet (UV) rays using polymeric nanocomposite particles and presents a method for producing such particles. The process involves encapsulating organic sunscreen agents in amorphous nanoparticles with the aid of an amphiphilic copolymer. The resulting particles, according to the invention, improve dispersion, minimize skin irritation, enhance applicability in cosmetic products, and offer protection against UV rays. The nanoparticles consist of the organic sunscreen agent, the amphiphilic copolymer, and a hydrophobic core-forming polymer, with an average diameter ranging from 10 to 10,000 nanometers. Such particles can be incorporated as active ingredients in cosmetic compositions for UV protection.The invention also mentions the use of polyesters as part of the components used in the production of polymer composites, contributing to the stability and effectiveness of the particles in retaining the sunscreen agent in an amorphous state.

[0019] The present invention, however, differs from the previous document in that it produces micro and nanoparticles based on starch and succinates, such as succinic acid and diethyl succinate, compounds not mentioned in the previous document. The previous document involves the production of nanoparticles based on methoxy poly(ethylene glycol)-b-poly(caprolactone) and materials such as poly(vinyl imidazole), chlorosulfate polyolefins, polyethylene oxide, and their copolymers. Therefore, the polymeric materials cited in the previous invention and presented in the examples are non-biodegradable and of fossil origin, unlike those presented in the present invention.

[0020] Although some of the aforementioned documents highlight the intrinsic advantages of encapsulating active ingredients (such as improved formulation dispersion, reduced skin absorption, and increased stability), it is important to note that all of the aforementioned documents present nanoparticles composed of polymeric materials different from those used in the present invention. In all cases presented, the matrices employed are not biodegradable. In contrast, the present invention is characterized by the production of micro and nanoparticles made with biodegradable matrices, containing or not encapsulated active ingredients, applied in sunscreen formulations. Therefore, the present invention encompasses more natural and low-impact materials, ensuring environmental conservation. SUMMARY OF THE INVENTION

[0021] Regular use of sunscreens is encouraged by many health experts. However, many of these photoprotective compounds have allergenic and / or carcinogenic effects and permeate the skin, reaching the deeper layers after a certain period of contact.

[0022] In this context, the present invention proposes the production of biodegradable polymeric nanoparticles and microparticles, which may or may not contain encapsulated active ingredients, and the use of such particles as sunscreens or sun protection enhancers in sunscreen formulations.

[0023] This combines the reflectance effect of the particles with the chemical effect of chemical photoprotective compounds, increasing the stability of the active ingredients and reducing the concentration of photoprotective active ingredients required to achieve the desired photoprotection factors in formulations, while also ensuring environmental preservation. It is important to emphasize that the present invention is based on the use of sustainable, biodegradable polymers with low environmental impact, which do not result in bioaccumulation or the generation of microplastics.

[0024] The present invention can be better understood through the brief description of the figures presented below.

[0025] Figure 1 shows the characteristic particle size distributions of the polymeric materials produced from the present invention.

[0026] Figure 2 shows micrographs of particles produced according to the methodology presented in example 1: (A) Polyester 1; (B) Polyester 2.

[0027] Figure 3 shows micrographs of particles produced according to the methodology presented in example 2: (A) Polyester 1; (B) Polyester 2.

[0028] Figure 4 shows micrographs of particles produced according to the methodology presented in example 4: (A) Polyester 1; (B) Polyester 2.

[0029] Figure 5 illustrates the visual appearance of particulate latexes made from poly(butylene succinate) in the absence and presence of photoprotective actives when exposed to UV light. The white-appearing latex demonstrates the physical effect of the particles in the absence of actives, while the black-appearing latex confirms the encapsulation of the photoprotective actives through radiation absorption. DETAILED DESCRIPTION OF THE INVENTION

[0030] The invention can be better understood through the detailed description presented below, in line with the figures already presented.

[0031] The present invention describes a sustainable product, with low environmental impact, in the form of biodegradable polymeric micro or nanoparticles, which may or may not contain photoprotective active ingredients and the use of such particles as sunscreens or sun protection intensifiers in sunscreen formulations.

[0032] The proposed micro- or nanoparticles consist of at least one polymer or copolymer, which may or may not be cross-linked. Such particles can be produced in heterogeneous media, dispersed in an aqueous or oily medium, and may or may not be dried after production, allowing the original suspension to be used in the composition of the photoprotective formulation. Optionally, the micro- or nanoparticles may comprise at least one encapsulated photoprotective active ingredient.

[0033] The polymer or copolymer has the function of promoting the reflectance of solar rays and protecting the active ingredient, increasing the sun protection factor, and has a concentration in the range of 20 to 80% m / m, preferably in the range of 40 to 75% m / m to avoid agglomeration and to increase productivity and efficiency of storage and transportation.

[0034] Polymers or copolymers, whether loaded with active ingredients or not, have a critical wavelength above 350 nm, preferably in the range of 375 to 395 nm, to ensure the absorption of the most harmful ultraviolet radiation for health.

[0035] Polymers or copolymers, loaded or not with active ingredients, are presented in particulate form, preferably with characteristic diameters in the ranges of 100 nm to 100 µm, to enhance interactions with electromagnetic radiation that makes up the ultraviolet and visible regions.

[0036] The polymer or copolymer is preferably selected from the group comprising: starch, carrageenan, gelatin, chitosan, cross-linked or not with glutaraldehyde, glycerol, glucose, or a combination thereof, and polyester, being poly(ethylene succinate) (PES), poly(propylene succinate) (PPS), poly(butylene succinate) (PBS), poly(butylene succinate-co-adipate) (PBSA), poly(butylene succinate-co-tartrate) (PBSTar) and poly(butylene succinate-co-glutamate) (PBSGlu), copolymers containing succinic acid, adipic acid, lactic acid and glutamic acid, as reactant acids, and ethylene glycol, propylene glycol and / or butanediol, as reactant alcohols, or a combination thereof, preferably being poly(ethylene succinate), poly(butylene succinate-co-adipate) and poly(butylene succinate). It is worth noting that the choice of polymer or copolymer is not limited to the mentioned group.

[0037] Non-crosslinked polymers must be soluble in solvents such as water, ethanol, dimethyl sulfoxide, or ionic liquids for the encapsulation process to be carried out. This also allows the use of the aforementioned compounds to crosslink the polymer chains and render them insoluble, forming particles.

[0038] The protective active ingredient absorbs ultraviolet rays and blue light and must be present in concentrations of 1 to 50% w / w, preferably 1 to 30% w / w, to maximize the efficiency of its use without compromising particle integrity and preventing unwanted release into the environment. The protective active ingredient is preferably selected from the group comprising: andiroba oil, copaiba oil, passion fruit oil, tonka bean oil, buriti oil, jojoba oil, 1-(4-methoxyphenol)-3-(4-tert-butylphenyl)propane-1,3-dione (INCI: avobenzone), octyl methoxycinnamate, 2-ethylhexyl-2-cyano-3,3-diphenyl-2-propenoate (INCI: octocrylene), triazines, octyl salicylate, homosalate, benzoate, benzophenones, or a combination thereof. It is worth noting that the choice of asset is not limited to the group mentioned.

[0039] Biodegradable polymeric micro- and nanoparticles can be produced using various particle production techniques that utilize pre-synthesized polymer, such as spraying, solvent evaporation, microfluidics, and supercritical CO2 dispersion. In all cases, a polymer solution is used to produce the particles, which can be separated from the dispersed medium by various methods, such as filtration, drying, or centrifugation. Generally, biodegradable polymeric micro- and nanoparticles are produced using one of the following processes: micro- or nanoprecipitation; and in situ encapsulation.

[0040] In process (a), polymeric micro- or nanoparticles are produced using the micro- or nanoprecipitation technique, respectively. To achieve this, a polymer solution is prepared by diluting the polymer or copolymer in a solvent. For polymers such as starch, carrageenan, gelatin, and chitosan, water, ionic liquids, or other similar polar compounds are used as the solvent. For polymers derived from succinic acid, solvents such as chloroform, dichloromethane, or dimethyl sulfoxide are used. The mixture is heated to temperatures between 25-80°C for 1 hour with continuous stirring until the polymer is completely dissolved. Subsequently, the polymer solution is slowly added to a non-solvent, with or without dissolved surfactant, at room temperature. For polymers such as starch, carrageenan, gelatin, and chitosan, non-solvents such as vegetable oil, mineral oil, or silicone oil are used.For polymers derived from succinic acid, water is used as the non-solvent. The mixture containing the non-solvent is subjected to a high-shear process using equipment such as a sonicator, high-speed disperser, or homogenizer. The resulting emulsion is then subjected to controlled agitation at a speed of 100 to 900 rpm, depending on the system's characteristics, to produce particles of the desired size. Finally, the resulting particles are separated by filtration or kept in suspension for later use.

[0041] To perform the in-situ encapsulation of the photoprotective active ingredient according to process (b), the active ingredient with sunscreen action is solubilized in the polymer solution. The polymer solution containing the active ingredient is then slowly added to a non-solvent at temperatures between 25°C and 80°C. For polymers such as starch, carrageenan, gelatin, and chitosan, non-solvents such as vegetable oil, mineral oil, or silicone oil are used. For polymers derived from succinic acid, water is used as the non-solvent. The mixture is subjected to controlled agitation at a speed of 100 to 900 rpm, depending on the system's characteristics, to produce particles of the desired size. Finally, the resulting particles are separated by filtration or kept in suspension for later use.

[0042] Micro- or nanoparticles can be used as sunscreens or sunscreen enhancers in the production of sunscreens or multifunctional products, which have other functions with UV protection benefits. Multifunctional products are understood to be any cosmetic formulation whose UV protection is an additional, non-primary benefit, such as lipsticks and styling creams, but not limited to these products.

[0043] The invention will be elucidated with the examples shown below, without being limited to or by them. Examples

[0044] Example 1: Production of PBS and PBSA particles with photoprotective action

[0045] Biodegradable polymeric particles based on poly(butylene succinate) (PBS) and poly(butylene succinate-co-adipate) (PBSA) copolymer were produced by non-solvent precipitation methodology. Thus, the polymeric material was previously solubilized in chloroform at a concentration of 10% w / m and poured into an aqueous solution containing polyvinyl alcohol (PVA) at a concentration of 2% w / m. Both phases were subjected to high shear stresses under sonication at 30% amplitude for 5 min. Subsequently, this emulsion was poured back into an aqueous solution with a PVA concentration of 0.5% w / m. The described system was kept under constant stirring at 900 rpm for 24 h, resulting in particles with an average diameter of approximately 400 nm. The produced particles had a critical wavelength of 387 nm and an in vitro sun protection factor of 5.

[0046] The particles exhibited broad size distributions, with diameters ranging from 100 nm to 10 µm, as shown in Figure 1.

[0047] The PBS and PBSA particles in the absence of active ingredients presented spherical morphology with a smooth surface, as can be seen in Figure 2.

[0048] Example 2: Production of PBS and PBSA particles containing encapsulated photoprotective active

[0049] Biodegradable polymeric particles based on poly(butylene succinate) (PBS) and poly(butylene succinate-co-adipate) (PBSA) copolymer were produced by non-solvent precipitation methodology. The polymeric material (10% w / w), photoprotective actives such as avobenzone (2% w / w), octocrylene (2% w / w) and octyl methoxycinnamate (1% w / w) were previously solubilized in chloroform and poured into an aqueous solution containing PVA (2% w / w). The two phases were subjected to high shear stresses under sonication with an amplitude of 30% for 5 min. Then, the resulting emulsion was poured into an aqueous solution with a PVA concentration of 0.5% w / w. As in Example 1, the system described was subjected to constant stirring at 900 rpm for 24 hours, resulting in particles with an average diameter of approximately 800 nm.The particles produced have a critical wavelength of 384 nm and an in vitro sun protection factor between 20 and 130, depending on the particle concentration used.

[0050] The particles exhibited broad size distributions, with diameters ranging from 100 nm to 10 µm, as shown in Figure 1.

[0051] The PBS and PBSA particles containing the photoprotective actives presented a mostly spherical morphology with the presence of some agglomerates, as can be seen in Figure 3.

[0052] The latexes of the poly(butylene succinate)-based particles containing the photoprotective actives were subjected to UV light, as shown in Figure 4. The white-appearing latex shows the physical effect of the particles in the absence of actives, and the black-appearing latex confirms the encapsulation of the photoprotective actives through radiation absorption.

[0053] Example 3: Production of PES particles containing encapsulated photoprotective active ingredient

[0054] Biodegradable polymeric particles based on poly(ethylene succinate) (PES) were produced by the non-solvent precipitation methodology. The polymeric material (10% w / w) and photoprotective actives such as avobenzone (2% w / w), octocrylene (2% w / w), and octyl methoxycinnamate (1% w / w) were previously solubilized in chloroform and poured into an aqueous PVA solution (2% w / w). The two phases were subjected to high shear stresses under sonication at 30% amplitude for 5 min. Subsequently, the resulting emulsion was poured into an aqueous solution with a PVA concentration of 0.5% w / w. As in Example 2, the described system was subjected to constant stirring at 900 rpm for 24 h, resulting in particles with an average diameter of approximately 800 nm. The particles produced have a critical wavelength of 386 nm and an in vitro sun protection factor above 80, depending on the particle concentration used.

[0055] Example 4: Production of starch particles containing encapsulated photoprotective active ingredient

[0056] Natural and biodegradable starch-based polymeric microparticles were produced by the in situ encapsulation methodology. Starch (2.4% w / w), a solution of the photoprotective active ingredients ensulizole and benzophenone-4 (21.1% w / w), and glycerol (0.9% w / w) were previously solubilized in water (0.6% w / w) and poured into an oil solution containing sorbitan monooleate (3.8% w / w). The two phases were subjected to high shear stresses, with sonication at 20% amplitude for 5 min. Then, the resulting emulsion (W / O) was poured into a reactor maintained under constant stirring and heated to 80°C for 5 h, for solvent evaporation and chain crosslinking. The particles produced were washed with acetone and separated from the oily medium by filtration, resulting in particles with an average diameter of approximately 70 µm.The particles produced had a critical wavelength of 370 nm and an in vitro sun protection factor of approximately 5, depending on the particle concentration used.

[0057] Example 5: Cosmetic formulation containing PBS particles

[0058] Biodegradable polymeric particles based on poly(butylene succinate) containing photoprotective active ingredients such as avobenzone, octocrylene, and octylmethoxycinnamate were added to a base formulation at a concentration of 18%, and the photoprotection factor (SPF) of this formulation was evaluated. An in vitro SPF of 23 ± 5 was obtained, while for a formulation containing the same concentration of filters, but in free form, an SPF of 5 ± 0.5 was obtained. Thus, the effectiveness of one of the products originating from this invention is proven.

[0059] The present invention has been disclosed in this descriptive report in terms of its preferred embodiment. However, other modifications and variations are possible from the present description, still being within the scope of the invention disclosed herein. BIBLIOGRAPHICAL REFERENCES

[0060] FLOR, J.; DAVOLOS, MR; CORREA, MA Sunscreens. Química Nova, v. 30, p. 153–158, Feb. 2007.

[0061] HUBER, U.; SCHEHLMANN, V.; HOTZ, J.; SPRENGER, D. ADDITIVE FOR UV SUNSCREEN PREPARATIONS. Applicant: DSM IP Assets BV PI 0517930-0 A. Deposit: October 26, 2005. Granted: October 21, 2008.

[0062] LEE, SH; SHIM, WS; BONG, HJ; HWAN, YM; KANG, NG Nanoparticles composed of stably suspended polymers containing organic sunscreen agents and method for the preparation thereof. KR20180024903A. Deposit: Aug. 31, 2016. Grant: Mar. 8, 2018

[0063] LORCA, BSES Development of Photoprotective Formulation Containing Polymeric Nanoparticles with Sunscreen. PhD—Rio de Janeiro: Federal University of Rio de Janeiro, 2012.

[0064] MANAIA, EB; KAMINSKI, RCK; CORRÊA, MA; CHIAVACCI, LA Inorganic UV filters. Brazilian Journal of Pharmaceutical Sciences, v. 49, p. 201–209, jun. 2013.

[0065] PLESSIX, H.; MONDET, J.; DE, RJ UV-Photoprotective cosmetic compositions comprising polymer particles / fatty phases having unique refractive indices. Depositor: L'Oreal SA. US5932194A. Deposit: 4 Mar. 1998. Concession: 3 Aug. 1999

[0066] XU, W.; ZENG, F.; YEZER, B.; CHEN, L.; SCHMIDT, D.C.; SHULMAN, I. SUNSCREEN FORMULATION. Applicant: DOW GLOBAL TECHNOLOGIES and ROHM AND HAAS COMPANY. BR 112020000940-7 A2. Filing: June 28, 2018. Granted: July 21, 2020

Claims

Biodegradable polymeric micro and nanoparticles, CHARACTERIZED by the fact that they comprise a cross-linked or non-cross-linked polymer or copolymer, which may or may not contain one or more encapsulated photoprotective active ingredients. Biodegradable polymeric micro and nanoparticles, according to claim 1, CHARACTERIZED by the fact that the polymer or copolymer is selected from the group comprising: starch, carrageenan, gelatin, chitosan, cross-linked or not with glutaraldehyde, glycerol, glucose, or a combination thereof, and polyester, being poly(ethylene succinate) (PES), poly(propylene succinate) (PPS), poly(butylene succinate) (PBS), poly(butylene succinate-co-adipate) (PBSA), poly(butylene succinate-co-tartrate) (PBSTar) and poly(butylene succinate-co-glutamate) (PBSGlu), copolymers containing succinic acid, adipic acid, lactic acid and glutamic acid, as reagent acids, and ethylene glycol, propylene glycol and / or butanediol, as alcohols reagents, or a combination thereof, preferably poly(ethylene succinate), poly(butylene succinate-co-adipate) and poly(butylene succinate). Biodegradable polymeric micro and nanoparticles, according to any one of claims 1 and 2, CHARACTERIZED by the fact that the polymer or copolymer has a concentration in the range of 20 to 80% m / m, preferably 40 to 75% m / m. Biodegradable polymeric micro and nanoparticles, according to claim 1, CHARACTERIZED by the fact that the photoprotective active is preferably selected from the group comprising: andiroba oil, copaiba oil, passion fruit oil, cumaru oil, buriti oil, jojoba oil, 1-(4-methoxyphenol)-3-(4-tertbutylphenyl)propane-1,3-dione (INCI: avobenzone), octyl methoxycinnamate, 2-ethylhexyl-2-cyano-3, 3-diphenyl-2-propenoate (INCI: octocrylene), triazines, octyl salicylate, homosalate, benzoate, benzophenones or a combination thereof. Biodegradable polymeric micro and nanoparticles, according to claims 1 and 4, CHARACTERIZED by the fact that the protective active ingredient has a concentration in the range of 1 to 50% m / m, preferably 1 to 30% m / m. Use of biodegradable polymeric micro and nanoparticles, as defined in claims 1 to 5, CHARACTERIZED for being used as sunscreens or sun protection enhancers in sunscreen formulations or multifunctional cosmetic products.

Images