UV absorbing cosmetic compositions that exhibit sun protection factor boosting in the presence of biodegradable cellulose ester microbeads

Abstract

Cosmetic compositions comprising biodegradable microbeads formed from biodegradable mixed cellulose esters are provided. More particularly, cosmetic compositions are provided that contain environmentally friendly cellulose-based microbeads, which can be used in a wide array of cosmetic and personal care applications. The produced microbeads also exhibit enhanced solidity, sphericity, and smoothness.

Description

[0001] UV ABSORBING COSMETIC COMPOSITIONS THAT EXHIBIT SUN PROTECTION FACTOR BOOSTING IN THE PRESENCE OF BIODEGRADABLE CELLULOSE ESTER MICROBEADS

[0002] BACKGROUND

[0003] Microbeads are particles that are less than 1 millimeter (mm) in diameter. These particles are sometimes included in consumer products, such as personal care and cosmetic products. Many of these microbeadcontaining products are designed to be applied and then washed or rinsed from the user’s body. When the microbead-containing products are washed or rinsed from the user’s body, the particles are flushed down the drain and received at municipal water treatment facilities. In the past, many known microbeads had been formed from plastic or polymeric materials, such as polyethylene, polypropylene, polymethyl methacrylate, nylon, polyurethane, and the like. These materials generally have limited biodegradability. In addition, the small size of the particles limits their ability to be captured at the water treatment facilities, such that the particles may be discharged from the facilities and into larger bodies of water (e.g., rivers, seas, and oceans). Once in these larger bodies of water, the plastic or polymeric microbeads may be ingested by wildlife or cause other environmental concerns. Thus, the possibility of producing microbead particles from more environmentally friendly materials has recently been explored. However, consumers tend to have high expectations when it comes to the personal care and / or cosmetic products they use, including those containing microbeads.

[0004] It has been unexpectedly discovered that UV absorbing cosmetic compositions exhibit sun protection factor boosting in the presence of biodegradable cellulose ester microbeads. Thus, it is desirable to develop commercially desirable UV absorbing cosmetic compositions containing biodegradable cellulose ester microbeads that meet the high expectations of everyday consumers. SUMMARY

[0005] The present application discloses a cosmetic composition comprising:

[0006] (1) biodegradable microparticles, wherein the biodegradable microparticles comprise a cellulose ester, wherein:

[0007] (a) the biodegradable microparticles exhibit at least 30 percent biodegradability at 60 days according to at least one of the OECD 301 B, OECD 301 C, or OECD 301 F test methods, and

[0008] (b) the biodegradable particles are formed by mechanical milling; and

[0009] (2) at least one UV filter agent other than the biodegradable microparticles, wherein the cosmetic composition exhibits a sun protection factor (“SPF”) value, and wherein the SPF value is at least 10% higher than a cosmetic composition comprising a UV filter agent without the biodegradable microparticles.

[0010] The present application also discloses a use of biodegradable microparticles as a sun protection factor (“SPF”) booster in a cosmetic composition, wherein:

[0011] (a) the biodegradable microparticles comprise a cellulose ester,

[0012] (b) the biodegradable microparticles exhibit at least 30 percent biodegradability at 60 days according to at least one of the OECD 301 B, OECD 301 C, or OECD 301 F test methods, and

[0013] (c) the biodegradable particles are formed by mechanical milling.

[0014] DETAILED DESCRIPTION

[0015] The present invention may be understood more readily by reference to the following detailed description and the examples provided therein. It is to be understood that this disclosure is not limited to the specific methods, formulations, and conditions described, as such may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects of the disclosed embodiments only and is not intended to be limiting.

[0016] Values may be expressed as “about” or “approximately” a given number. Similarly, ranges may be expressed herein as from “about” one particular value and / or to “about” or another particular value. When such a range is expressed, another aspect includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another aspect.

[0017] As used herein, the terms “a,” “an,” and “the” mean one or more.

[0018] As used herein, the term “and / or,” when used in a list of two or more items, means that any one of the listed items can be employed by itself or any combination of two or more of the listed items can be employed. For example, if a composition is described as containing components A, B, and / or C, the composition can contain A alone; B alone; C alone; A and B in combination; A and C in combination, B and C in combination; or A, B, and C in combination.

[0019] As used herein, the terms “comprising,” “comprises,” and “comprise” are open-ended transition terms used to transition from a subject recited before the term to one or more elements recited after the term, where the element or elements listed after the transition term are not necessarily the only elements that make up the subject.

[0020] As used herein, the terms “having,” “has,” and “have” have the same open-ended meaning as “comprising,” “comprises,” and “comprise” provided above.

[0021] As used herein, the terms “including,” “includes,” and “include” have the same open-ended meaning as “comprising,” “comprises,” and “comprise” provided above.

[0022] As used herein, a “mixed cellulose ester” shall denote a cellulose ester having at least two different ester substituents on a single cellulose ester polymer chain. As used herein, the term "SPF booster" means a material which increases the UV absorption of another material when the two are intermixed in a composition leading to an increase in the SPF value.

[0023] “Degree of Substitution” is used to describe the average substitution level of the substituents per anhydroglucose unit (“AGU”). Generally, conventional cellulose contains three hydroxyl groups in each AGU that can be substituted. Therefore, the DS can have a value between 0 and 3. However, low molecular weight cellulose mixed esters can have a total degree of substitution slightly above 3 from end group contributions. Low molecular weight cellulose mixed esters are discussed in more detail subsequently in this disclosure. Because DS is a statistical mean value, a value of 1 does not assure that every AGU has a single substituent. In some cases, there can be unsubstituted anhydroglucose units, some with two and some with three substituents, and more often than not the value will be a noninteger. Total DS is defined as the average number of all of substituents per anhydroglucose unit. The degree of substitution per AGU can also refer to a particular substituent, such as, for example, hydroxyl, acetyl, butyryl, or propionyl. Additionally, the degree of substitution can specify a given hydroxyl based on the carbon unit of the anhydroglucose unit.

[0024] When the degree of substitution refers to hydroxyl, i.e, DSOH, the reference is to the average hydroxyl groups per anhydroglucose that are not substituted. As a result, DSOH is not used in the calculation of the total degree of substitution.

[0025] The present description uses numerical ranges to quantify certain parameters relating to the invention. It should be understood that when numerical ranges are provided, such ranges are to be construed as providing literal support for claim limitations that only recite the lower value of the range as well as claim limitations that only recite the upper value of the range. For example, a disclosed numerical range of 10 to 100 provides literal support for a claim reciting “greater than 10” (with no upper bounds) and a claim reciting “less than 100” (with no lower bounds). The present description uses specific numerical values to quantify certain parameters relating to the invention, where the specific numerical values are not expressly part of a numerical range. It should be understood that each specific numerical value provided herein is to be construed as providing literal support for a broad, intermediate, and narrow range. The broad range associated with each specific numerical value is the numerical value plus and minus 60 percent of the numerical value, rounded to two significant digits. The intermediate range associated with each specific numerical value is the numerical value plus and minus 30 percent of the numerical value, rounded to two significant digits. The narrow range associated with each specific numerical value is the numerical value plus and minus 15 percent of the numerical value, rounded to two significant digits. For example, if the specification describes a specific temperature of 62 °F, such a description provides literal support for a broad numerical range of 25 °F to 99 °F (62 °F + / - 37 °F), an intermediate numerical range of 43 °F to 81 °F (62 DF + / - 19 °F), and a narrow numerical range of 53 °F to 71 °F (62 °F + / - 9 °F). These broad, intermediate, and narrow numerical ranges should be applied not only to the specific values, but should also be applied to differences between these specific values. Thus, if the specification describes a first pressure of 110 psia and a second pressure of 48 psia (a difference of 62 psi), the broad, intermediate, and narrow ranges for the pressure difference between these two streams would be 25 to 99 psi, 43 to 81 psi, and 53 to 71 psi, respectively.

[0026] Throughout this application, where patents or publications are referenced, the disclosures of these references in their entireties are intended to be incorporated by reference into this application, to the extent they are not inconsistent with the present invention, in order to more fully describe the state of the art to which the invention pertains. Cosmetic Compositions

[0027] The present application discloses a cosmetic composition comprising: (1) biodegradable microparticles, wherein the biodegradable microparticles comprise a cellulose ester, wherein: (a) the biodegradable microparticles exhibit at least 30 percent biodegradability at 60 days according to at least one of the OECD 301 B, OECD 301 C, or OECD 301 F test methods, and (b) the biodegradable particles are formed by mechanical milling; and (2) at least one UV filter agent other than the biodegradable microparticles, wherein the cosmetic composition exhibits a sun protection factor (“SPF”) value, and wherein the SPF value is at least 10% higher than a cosmetic composition comprising a UV filter agent without the biodegradable microparticles.

[0028] In one embodiment or in combination with any other embodiment, the at least one UV filter agent is an organic UV filter agent, an inorganic UV filter agent, or a combination thereof. In one class of this embodiment, the at least one UV filter agent is an organic UV filter agent. In one class of this embodiment, the at least one UV filter agent is an inorganic UV filter agent. In one class of this embodiment, the at least one UV filter agent is a combination of an organic UV filter agent and an inorganic UV filter agent.

[0029] Examples organic UV filter agents includes but are not limited to dioxybenzone, dihydroxyacetone, menthyl anthranilate, benzophenone-4, benzophenone-4,octocrylene, octylsalicylate, triethanolamine salicylate, cinoxate, oxybenzone, octocrylene, Digalloyl trioleate, p-dimethylacetic acid amyl, octyl methoxycinnamate, diethanolamine p- methoxycinnamate, diethanolamine p-methoxycinnamate, Ethylmethoxycinnamate, p-aminobenzoic acid (“PABA”), glyceryl PABA, ethyldihydroxypropyl PABA, octylmethoxycinnamate, p-aminobenzoic acid, glycerylPABA, 2-phenylbenzimidazole-5-sulphonic acid, octyldimetyl PABA, 2- phenylbenzimidazole-5-sulphonic acid, homosalate, drometrizole, Butylmethoxydibenzoylmethane, octyltriazone, 3-(4-methylbenzylitene)- camphor, butylmethoxydibenzoylmethane, octyltriazone, 3-(4- methylbenzylitene)-camphor, 4-methylbenzylidene camphor, 3- benzylidenecamphor, camphorbenzalkonium, 4-methylbenzylidene camphor, triethoxycaprylylsilane, Sulphobenzylidene camphor, sulphomethylbenzylidene camphor, or combinations thereof.

[0030] Examples of inorganic UV filter agents include but are not limited to titanium dioxide, zinc oxide, iron oxide, zirconium oxide, silicon dioxide, manganese oxide, aluminum oxide, cerium oxide, mica, silica, talc, kaolin, or combinations thereof.

[0031] In one embodiment or in combination with any other embodiment, the cosmetic composition comprises at least 0.1 , at least 0.5, at least 1 , at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10, at least 1 1 , at least 12, at least 13, at least 14, or at least 15 weight percent of the biodegradable microparticles.

[0032] In one embodiment or in combination with any other embodiment, the cosmetic composition comprises less than 99, or less than 90, or less than 80, or less than 70, or less than 60, or less than 50, or less than 40, or less than 30, or less than 25, or less than 20, or less than 15, or less than 10, or less than 5 weight percent of the biodegradable microparticles.

[0033] In one embodiment or in combination with any other embodiment, the cosmetic composition is a foundation, a sunscreen, a lipstick, a lip balm, a chapstick, a mascara, an eye shadow, a lotion, a dry shampoo, a lotion, a hair conditioner, or a skin moisturizer.

[0034] In one embodiment or in combination with any other embodiment, the cosmetic composition comprises at least 1 , at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, or at least 95 weight percent and / or less than 99, less than 95, less than 90, less than 85, less than 80, less than 75, less than 70, less than 65, or less than 60 weight percent of at least one, two, three, four, or five cosmetic additives, wherein the cosmetic additives comprise a colorant, an oil, a wax, a fatty acid, an alcohol, an ester, a hydrocarbon, a silicone oil, a surfactant, a metal soap, a moisturizer, a thickener, a UV absorber, an antioxidant, an oil absorbent, an exfoliant, water, or a combination thereof.

[0035] In one embodiment or in combination with any other embodiment, the mechanical milling is performed by a jet mill, a ball mill, a hammer mill, a pin mill, or a cryogenic mill. In one class of this embodiment, the mechanical milling is performed by a jet mill.

[0036] In one embodiment or in combination with any other embodiment, the cellulose ester comprises: (i) a plurality of acetyl substituents; and (ii) a plurality of hydroxyl substituents, wherein cellulose ester exhibits: (1) an average degree of substitution for acetyl substituents (“DSAC”) in the range of from 0.1 to 2.5, and (2) an average degree of substitution for hydroxyl substituents (“DSOH”) in the range of 0.5 to 2.8.

[0037] In one embodiment or in combination with any other embodiment, the cellulose ester further comprises a plurality of (C3-4)alkyl-CO- substituents, and wherein the cellulose ester further exhibits: (3) an average degree of substitution for (C3-4)alkyl-CO- (“DSAkco”) in the range of from 0.1 to 1.5.

[0038] In one embodiment or in combination with any other embodiment, the cellulose ester is a cellulose acetate, a cellulose acetate propionate, or a cellulose acetate butyrate.

[0039] In one embodiment or in combination with any other embodiment, the DSOH is in the range of from 0.6 to 1 .0.

[0040] In one embodiment or in combination with any other embodiment, the biodegradable microparticles exhibit a monomodal particle size distribution with a span of at least 0.5, at least 0.55, at least 0.60, at least 0.65, at least 0.70, at least 0.75, at least 0.80, at least 0.85, at least 0.9, at least 0.95, at least 1.0, at least 1 .05, at least 1 .1 , at least 1.15, at least 1.2, or at least 1 .25 and / or less than 3.0, less than 2.9, less than 2.8, less than 2.7, less than 2.6, less than 2.5, less than 2.4, less than 2.3, less than 2.2, less than 2.1 , less than 2.0, less than 1 .9, less than 1.8, less than 1 .7, or less than 1 .6, wherein the biodegradable microparticles have a D50 particle size in the range of 1 to 20, or 1 to 18, or 1 to 16, or 1 to 14, or 1 to 12, or 2 to 20, or 2 to 18, or 2 to 16, or 2 to 14, or 2 to 12, or 4 to 20, or 4 to 18, or 4 to 16, or 4 to 14, or 4 to

[0041] 12, or 6 to 20, or 6 to 18, or 6 to 16, or 6 to 14, or 6 to 12, or 8 to 20, or 8 to

[0042] 18, or 8 to 16, or 8 to 14, or 8 to 12 microns.

[0043] In one class of this embodiment, the biodegradable microparticles have a D10 particle size in the range of 1 to 6, or 1 to 5, or 1 to 4, or 2 to 6, or 2 to 5, or 2 to 4, or 2 to 3, or 3 to 6, or 3 to 5, or 3 to 4 microns.

[0044] In one class of this embodiment, the biodegradable microparticles have a D90 particle size in the range of 1 to 26, or 1 to 24, or 1 to 22, or 1 to 20, or 1 to 18, or 1 to 16, or 1 to 14, or 2 to 26, or 2 to 24, or 2 to 22, or 2 to 20, or 2 to 18, or 2 to 16, or 2 to 14, or 4 to 26, or 4 to 24, or 4 to 22, or 4 to 20, or 4 to

[0045] 18, or 4 to 16, or 4 to 14, or 6 to 26, or 6 to 24, or 6 to 22, or 6 to 20, or 6 to

[0046] 18, or 6 to 16, or 6 to 14, or 8 to 26, or 8 to 24, or 8 to 22, or 8 to 20, or 8 to

[0047] 18, or 8 to 16, or 8 to 14, or 10 to 26, or 10 to 24, or 10 to 22, or 10 to 20, or

[0048] 10 to 18, or 10 to 16, or 10 to 14, or 12 to 26, or 12 to 24, or 12 to 22, or 12 to

[0049] 20, or 12 to 18, or 12 to 16, or 12 to 14, or 14 to 26, or 14 to 24, or 14 to 22, or

[0050] 14 to 20, or 14 to 18, or 14 to 16, or 16 to 26, or 16 to 24, or 16 to 22, or 16 to

[0051] 20, or 16 to 18, or 18 to 26, or 18 to 24, or 18 to 22, or 18 to 20 microns.

[0052] In one embodiment or in combination with any other embodiment, the biodegradable microparticles have a polydispersity index of less than 0.8, less than 0.7, less than 0.6, less than 0.5, less than 0.4, or less than 0.3.

[0053] In one embodiment or in combination with any other embodiment, the biodegradable microparticles have a sphericity of less than 80, or of less than 75, or of less than 70, or of less than 65, or of less than 60, or of less than 55 percent.

[0054] In one embodiment or in combination with any other embodiment, the biodegradable microparticles have an average smoothness of at least 10, 20, 30, 40, 50, 60, 70, 80, 90, 95, 95, 97, 98, or 99 percent and / or not more than 99, 95, 90, 80, 70, 60, 50, 40, 30, 20, or 10 percent.

[0055] In one embodiment or in combination with any other embodiment, the biodegradable microparticles exhibit an oil absorption of at least 30 mL per 100 g at least 35 mL per 100 g, at least 40 mL per 100 g, at least 45 mL per 100 g, at least 50 mL per 100 g, at least 55 mL per 100 g, or at least 60 mL per 100 g as measured using test method ASTM D281 , wherein mineral oil is used instead of castor oil.

[0056] In one embodiment or in combination with any other embodiment, the biodegradable microparticles have an average BET surface area in the range of 0.1 to 100 m2 / g as measured according to ISO 9277 using a Micromeritics ASAP 2020 instrument and krypton gas.

[0057] In one embodiment or in combination with any other embodiment, the biodegradable microparticles have a butyric acid content of less than 100, less than 50, less than 20, less than 10, less than 7.5, less than 5, less than 2.5, or less than 1 ppmw, wherein the biodegradable microparticles have an acetic acid content of less than 500, less than 300, less than 100, less than 50, less than 20, less than 10, less than 7.5, less than 5, less than 2.5, or less than 1 ppmw.

[0058] In one embodiment or in combination with any other embodiment, the biodegradable microparticles exhibit at least 60 percent biodegradability at 60 days according to at least one of the OECD 301 B, OECD 301 C, or OECD 301 F test methods.

[0059] In one embodiment or in combination with any other embodiment, the biodegradable microparticles further comprise at least one organic acid salt.

[0060] In one class or in combination with any other class in this embodiment, the at least one organic acid salt comprises an alkali metal cation or an alkaline metal cation.

[0061] In one subclass of this class or in combination with any other embodiment, class or subclass, the alkali metal cation is Li+, Na+, or K+, and the alkaline metal cation is Mg2+or Ca2+.

[0062] In one class of this embodiment or in combination with any other embodiment, class, or subclass, the organic acid component of the at least one organic acid salt is derived from a compound of formula wherein: G is a (Ci-8)alkylene, wherein the alkylene is unsubstituted or substituted by 1 to 2 hydroxyl substituents, a (Ci-8)alkenyl, or a phenyl; and n is 0, 1 , or 2.

[0063] In one subclass of this class or in combination with any other embodiment, class, or subclass, the compound of formula I is glutaric acid, pimelic acid, azelaic acid, sebacic acid, suberic acid, adipic acid, succinic acid, citric acid, tartaric acid, fumaric acid, terephthalic acid, isophthalic acid, acetic acid, or propionic acid, or lactic acid. In one sub-subclass of this class, the compound of formula I is succinic acid. In one sub-subclass of this class, the compound of formula I is citric acid. In one sub-subclass of this class, the compound of formula I is lactic acid. In one sub-subclass of this class, the compound of formula I is acetic acid. In one sub-subclass of this class, the compound of formula I is propionic acid. In one sub-subclass of this class, the compound of formula I is tartaric acid. In one sub-subclass of this class, the compound of formula I is glutaric acid. In one sub-subclass of this class, the compound of formula I is adipic acid.

[0064] In one subclass of this class or in combination with any other embodiment, class, or subclass, the organic acid salt is sodium succinate, potassium succinate, magnesium succinate, calcium succinate, sodium citrate, potassium citrate, magnesium citrate, calcium citrate, sodium acetate, potassium acetate, magnesium acetate, calcium acetate, sodium lactate, potassium lactate, magnesium lactate, or calcium lactate.

[0065] In one sub-subclass of this subclass, or in combination with any other embodiment, class, or subclass, the organic acid salt is sodium succinate, potassium succinate, magnesium succinate, or calcium succinate. In one subsubclass of this subclass, or in combination with any other embodiment, class, or subclass, the organic acid salt is sodium succinate. In one sub-subclass of this subclass, or in combination with any other embodiment, class, or subclass, the organic acid salt is potassium succinate. In one sub-subclass of this subclass, or in combination with any other embodiment, class, or subclass, the organic acid salt is magnesium succinate. In one sub-subclass of this subclass, or in combination with any other embodiment, class, or subclass, the organic acid salt is calcium succinate.

[0066] Use of the Biodegradable Microparticles as Sun Protection Factor Boosters The present application also discloses a use of biodegradable microparticles as a sun protection factor (“SPF”) booster in a cosmetic composition, wherein: (a) the biodegradable particles comprise a cellulose ester, (b) the biodegradable microparticles exhibit at least 30 percent biodegradability at 60 days according to at least one of the OECD 301 B, OECD 301 C, or OECD 301 F test methods, and (c) the biodegradable particles are formed by mechanical milling.

[0067] In one embodiment or in combination with any other embodiment, the cellulose ester comprises: (i) a plurality of acetyl substituents; and (ii) a plurality of hydroxyl substituents, wherein cellulose ester exhibits: (1) an average degree of substitution for acetyl substituents (“DSAC”) in the range of from 0.1 to 2.5, and (2) an average degree of substitution for hydroxyl substituents (“DSOH”) in the range of 0.5 to 2.8.

[0068] In one embodiment or in combination with any other embodiment, the cellulose ester further comprises a plurality of (C3-4)alkyl-CO- substituents, and wherein the cellulose ester further exhibits: (3) an average degree of substitution for (C3-4)alkyl-CO- (“DSAkco”) in the range of from 0.1 to 1.5.

[0069] In one embodiment or in combination with any other embodiment, the cellulose ester is a cellulose acetate, a cellulose acetate propionate, or a cellulose acetate butyrate.

[0070] In one embodiment or in combination with any other embodiment, the DSOH is in the range of from 0.6 to 1 .0. In one embodiment or in combination with any other embodiment, the biodegradable microparticles exhibit a monomodal particle size distribution with a span of at least 0.5, at least 0.55, at least 0.60, at least 0.65, at least 0.70, at least 0.75, at least 0.80, at least 0.85, at least 0.9, at least 0.95, at least 1.0, at least 1 .05, at least 1 .1 , at least 1.15, at least 1.2, or at least 1 .25 and / or less than 3.0, less than 2.9, less than 2.8, less than 2.7, less than 2.6, less than 2.5, less than 2.4, less than 2.3, less than 2.2, less than 2.1 , less than 2.0, less than 1 .9, less than 1 .8, less than 1 .7, or less than 1 .6, wherein the biodegradable microparticles have a D100 particle size in the range of 1 to 100, 1 to 80, 1 to 70, 1 to 60, 1 to 50, 1 to 40, 1 to 35, 1 to 30, 1 to 25, 1 to 20, 1 to 15, 1 to 10, 5 to 100, 5 to 80, 5 to 70, 5 to 60, 5 to 50, 5 to 40, 5 to 35, 5 to 30, 5 to 25, 5 to 20, 5 to 15, 5 to 10, 10 to 100, 10 to 80, 10 to 70, 10 to 60, 10 to 50, 10 to 40, 10 to 35, 10 to 30, 10 to 25, 10 to 20, 10 to 15, 15 to 100, 15 to 80, 15 to 70, 15 to 60, 15 to 50, 15 to 40, 15 to 35, 15 to 30, 15 to 25, 15 to 20, 20 to 100, 20 to 80, 20 to 70, 20 to 60, 20 to 50, 20 to 40, 20 to 35, 20 to 30, 25 to 100, 25 to 80, 25 to 70, 25 to 60, 25 to 50, 25 to 40, 25 to 35, 25 to 30, 30 to 100, 30 to 80, 30 to 70, 30 to 60, 30 to 50, 30 to 40, or 30 to 35 microns.

[0071] In one embodiment or in combination with any other embodiment, the biodegradable microparticles have a polydispersity index of less than 0.8, less than 0.7, less than 0.6, less than 0.5, less than 0.4, or less than 0.3.

[0072] In one embodiment or in combination with any other embodiment, the biodegradable microparticles have a sphericity of less than 80, or of less than 75, or of less than 70, or of less than 65, or of less than 60, or of less than 55 percent.

[0073] In one embodiment or in combination with any other embodiment, the biodegradable microparticles have an average smoothness of at least 10, 20, 30, 40, 50, 60, 70, 80, 90, 95, 95, 97, 98, or 99 percent and / or not more than 99, 95, 90, 80, 70, 60, 50, 40, 30, 20, or 10 percent.

[0074] In one embodiment or in combination with any other embodiment, the biodegradable microparticles exhibit an oil absorption of at least 30 mL per 100 g at least 35 mL per 100 g, at least 40 mL per 100 g, at least 45 mL per 100 g, at least 50 mL per 100 g, at least 55 mL per 100 g, or at least 60 mL per 100 g as measured using test method ASTM D281 , wherein mineral oil is used instead of castor oil.

[0075] In one embodiment or in combination with any other embodiment, the biodegradable microparticles have an average BET surface area in the range of 0.1 to 100 m2 / g as measured according to ISO 9277 using a Micromeritics ASAP 2020 instrument and krypton gas.

[0076] In one embodiment or in combination with any other embodiment, the biodegradable microparticles have a butyric acid content of less than 100, less than 50, less than 20, less than 10, less than 7.5, less than 5, less than 2.5, or less than 1 ppmw, wherein the biodegradable microparticles have an acetic acid content of less than 500, less than 300, less than 100, less than 50, less than 20, less than 10, less than 7.5, less than 5, less than 2.5, or less than 1 ppmw.

[0077] In one embodiment or in combination with any other embodiment, the biodegradable microparticles exhibit at least 60 percent biodegradability at 60 days according to at least one of the OECD 301 B, OECD 301 C, or OECD 301 F test methods.

[0078] In one embodiment or in combination with any other embodiment, the biodegradable microparticles further comprise at least one organic acid salt.

[0079] In one class or in combination with any other class in this embodiment, the at least one organic acid salt comprises an alkali metal cation or an alkaline metal cation.

[0080] In one subclass of this class or in combination with any other embodiment, class or subclass, the alkali metal cation is Li+, Na+, or K+, and the alkaline metal cation is Mg2+or Ca2+.

[0081] In one class of this embodiment or in combination with any other embodiment, class, or subclass, the organic acid component of the at least one organic acid salt is derived from a compound of formula wherein: G is a (Ci-8)alkylene, wherein the alkylene is unsubstituted or substituted by 1 to 2 hydroxyl substituents, a (Ci-8)alkenyl, or a phenyl; and n is 0, 1 , or 2.

[0082] In one subclass of this class or in combination with any other embodiment, class, or subclass, the compound of formula I is glutaric acid, pimelic acid, azelaic acid, sebacic acid, suberic acid, adipic acid, succinic acid, citric acid, tartaric acid, fumaric acid, terephthalic acid, isophthalic acid, acetic acid, or propionic acid, or lactic acid. In one sub-subclass of this class, the compound of formula I is succinic acid. In one sub-subclass of this class, the compound of formula I is citric acid. In one sub-subclass of this class, the compound of formula I is lactic acid. In one sub-subclass of this class, the compound of formula I is acetic acid. In one sub-subclass of this class, the compound of formula I is propionic acid. In one sub-subclass of this class, the compound of formula I is tartaric acid. In one sub-subclass of this class, the compound of formula I is glutaric acid. In one sub-subclass of this class, the compound of formula I is adipic acid.

[0083] In one subclass of this class or in combination with any other embodiment, class, or subclass, the organic acid salt is sodium succinate, potassium succinate, magnesium succinate, calcium succinate, sodium citrate, potassium citrate, magnesium citrate, calcium citrate, sodium acetate, potassium acetate, magnesium acetate, calcium acetate, sodium lactate, potassium lactate, magnesium lactate, or calcium lactate.

[0084] In one sub-subclass of this subclass, or in combination with any other embodiment, class, or subclass, the organic acid salt is sodium succinate, potassium succinate, magnesium succinate, or calcium succinate. In one subsubclass of this subclass, or in combination with any other embodiment, class, or subclass, the organic acid salt is sodium succinate. In one sub-subclass of this subclass, or in combination with any other embodiment, class, or subclass, the organic acid salt is potassium succinate. In one sub-subclass of this subclass, or in combination with any other embodiment, class, or subclass, the organic acid salt is magnesium succinate. In one sub-subclass of this subclass, or in combination with any other embodiment, class, or subclass, the organic acid salt is calcium succinate.

[0085] Specific Embodiments

[0086] Embodiment 1 . A cosmetic composition comprising: (1 ) biodegradable microparticles, wherein the biodegradable microparticles comprise a cellulose ester, wherein: (a) the biodegradable microparticles exhibit at least 30 percent biodegradability at 60 days according to at least one of the OECD 301 B, OECD 301 C, or OECD 301 F test methods, and (b) the biodegradable particles are formed by mechanical milling; and (2) at least one UV filter agent other than the biodegradable microparticles, wherein the cosmetic composition exhibits a sun protection factor (“SPF”) value, and wherein the SPF value is at least 10% higher than a cosmetic composition comprising a UV filter agent without the biodegradable microparticles.

[0087] Embodiment 2. The cosmetic composition of Embodiment 1 , wherein the at least one UV filter agent is an organic UV filter agent, an inorganic UV filter agent, or a combination thereof.

[0088] Embodiment 3. The cosmetic composition of any one of Embodiments 1 -2, wherein the organic UV filter agent is dioxybenzone, dihydroxyacetone, menthyl anthranilate, benzophenone-4, benzophenone-4,octocrylene, octylsalicylate, triethanolamine salicylate, cinoxate, oxybenzone, octocrylene, Digalloyl trioleate, p-dimethylacetic acid amyl, octyl methoxycinnamate, diethanolamine p-methoxycinnamate, diethanolamine p-methoxycinnamate, Ethylmethoxycinnamate, p-aminobenzoic acid (“PABA”), glyceryl PABA, ethyldihydroxypropyl PABA, octylmethoxycinnamate, p-aminobenzoic acid, glycerylPABA, 2-phenylbenzimidazole-5-sulphonic acid, octyldimetyl PABA, 2- phenylbenzimidazole-5-sulphonic acid, homosalate, drometrizole, Butylmethoxydibenzoylmethane, octyltriazone, 3-(4-methylbenzylitene)- camphor, butylmethoxydibenzoylmethane, octyltriazone, 3-(4- methylbenzylitene)-camphor, 4-methylbenzylidene camphor, 3- benzylidenecamphor, camphorbenzalkonium, 4-methylbenzylidene camphor, triethoxycaprylylsilane, Sulphobenzylidene camphor, sulphomethylbenzylidene camphor, or combinations thereof.

[0089] Embodiment 4. The cosmetic composition of any one of Embodiments 2 or 3, wherein the inorganic UV filter agent is titanium dioxide, zinc oxide, iron oxide, zirconium oxide, silicon dioxide, manganese oxide, aluminum oxide, cerium oxide, mica, silica, talc, kaolin, or combinations thereof.

[0090] Embodiment 5. The cosmetic composition of any one of Embodiments 1 -4, wherein the cosmetic composition comprises at least 0.1 , at least 0.5, at least 1 , at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10, at least 11 , at least 12, at least 13, at least 14, or at least 15 weight percent of the biodegradable microparticles.

[0091] Embodiment 6. The cosmetic composition of any one of Embodiments 1 -5, wherein the cosmetic composition comprises less than 99, or less than 90, or less than 80, or less than 70, or less than 60, or less than 50, or less than 40, or less than 30, or less than 25, or less than 20, or less than 15, or less than 10, or less than 5 weight percent of the biodegradable microparticles.

[0092] Embodiment 7. The cosmetic composition of any one of Embodiments 1 -6, wherein the cosmetic composition is a foundation, a sunscreen, a lipstick, a lip balm, a chapstick, a mascara, an eye shadow, a lotion, a dry shampoo, a lotion, a hair conditioner, or a skin moisturizer.

[0093] Embodiment 8. The cosmetic composition according to any one of Embodiments 1 -7, wherein the cosmetic composition comprises at least 1 , at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, or at least 95 weight percent and / or less than 99, less than 95, less than 90, less than 85, less than 80, less than 75, less than 70, less than 65, or less than 60 weight percent of at least one, two, three, four, or five cosmetic additives, wherein the cosmetic additives comprise a colorant, an oil, a wax, a fatty acid, an alcohol, an ester, a hydrocarbon, a silicone oil, a surfactant, a metal soap, a moisturizer, a thickener, a UV absorber, an antioxidant, an oil absorbent, an exfoliant, water, or a combination thereof.

[0094] Embodiment 9. Use of biodegradable microparticles as a sun protection factor (“SPF”) booster in a cosmetic composition, wherein:

[0095] (a) the biodegradable particles comprise a cellulose ester,

[0096] (b) the biodegradable microparticles exhibit at least 30 percent biodegradability at 60 days according to at least one of the OECD 301 B, OECD 301 C, or OECD 301 F test methods, and

[0097] (c) the biodegradable particles are formed by mechanical milling.

[0098] Embodiment 10. The cosmetic composition or use of any one of Embodiments 1 -9, wherein the mechanical milling is performed by a jet mill.

[0099] Embodiment 1 1 . The cosmetic composition or use of any one of Embodiments 1 -10, wherein the cellulose ester comprises: (i) a plurality of acetyl substituents; and (ii) a plurality of hydroxyl substituents, wherein cellulose ester exhibits: (1 ) an average degree of substitution for acetyl substituents (“DSAC”) in the range of from 0.1 to 2.5, and (2) an average degree of substitution for hydroxyl substituents (“DSOH”) in the range of 0.5 to 2.8.

[0100] Embodiment 12. The cosmetic composition or use of Embodiment 11 , wherein the cellulose ester further comprises a plurality of (C3-4)alkyl-CO- substituents, and wherein the cellulose ester further exhibits: (3) an average degree of substitution for (C3-4)alkyl-CO- (“DSAkco”) in the range of from 0.1 to 1.5.

[0101] Embodiment 13. The cosmetic composition or use of any one of Embodiments 1 -12, wherein the cellulose ester is a cellulose acetate, a cellulose acetate propionate, or a cellulose acetate butyrate. Embodiment 14. The cosmetic composition or use of any one of Embodiments 11 -13, wherein the DSOH is in the range of from 0.6 to 1.0.

[0102] Embodiment 15. The cosmetic composition or use of any one of Embodiments 1 -14, wherein the biodegradable microparticles exhibit a monomodal particle size distribution with a span of at least 0.5, at least 0.55, at least 0.60, at least 0.65, at least 0.70, at least 0.75, at least 0.80, at least 0.85, at least 0.9, at least 0.95, at least 1 .0, at least 1 .05, at least 1 .1 , at least 1 .15, at least 1 .2, or at least 1.25 and / or less than 3.0, less than 2.9, less than 2.8, less than 2.7, less than 2.6, less than 2.5, less than 2.4, less than 2.3, less than 2.2, less than 2.1 , less than 2.0, less than 1 .9, less than 1 .8, less than 1 .7, or less than 1.6, and wherein the biodegradable microparticles have a D50 particle size in the range of 1 to 20, or 1 to 18, or 1 to 16, or 1 to 14, or 1 to 12, or 2 to 20, or 2 to 18, or 2 to 16, or 2 to 14, or 2 to 12, or 4 to 20, or 4 to 18, or 4 to 16, or 4 to 14, or 4 to 12, or 6 to 20, or 6 to 18, or 6 to 16, or 6 to 14, or 6 to 12, or 8 to 20, or 8 to 18, or 8 to 16, or 8 to 14, or 8 to 12 microns.

[0103] Embodiment 16. The cosmetic composition or use of any one of Embodiments 1 -15, wherein the biodegradable microparticles have a polydispersity index of less than 0.8, less than 0.7, less than 0.6, less than 0.5, less than 0.4, or less than 0.3.

[0104] Embodiment 17. The cosmetic composition or use of any one of Embodiments 1 -16, wherein the biodegradable microparticles have a sphericity of less than 80, or of less than 75, or of less than 70, or of less than 65, or of less than 60, or of less than 55 percent.

[0105] Embodiment 18. The cosmetic composition or use of any one of Embodiments 1 -17, wherein the biodegradable microparticles have an average smoothness of at least 10, 20, 30, 40, 50, 60, 70, 80, 90, 95, 95, 97, 98, or 99 percent and / or not more than 99, 95, 90, 80, 70, 60, 50, 40, 30, 20, or 10 percent.

[0106] Embodiment 19. The cosmetic composition or use of any one of Embodiments 1 -18, wherein the biodegradable microparticles exhibit an oil absorption of at least 30 mL per 100 g at least 35 mL per 100 g, at least 40 mL per 100 g, at least 45 mL per 100 g, at least 50 mL per 100 g, at least 55 mL per 100 g, or at least 60 mL per 100 g as measured using test method ASTM D281 , wherein mineral oil is used instead of castor oil.

[0107] Embodiment 20. The cosmetic composition or use of any one of Embodiments 1 -19, wherein the biodegradable microparticles have an average BET surface area in the range of 0.1 to 100 m2 / g as measured according to ISO 9277 using a Micromeritics ASAP 2020 instrument and krypton gas.

[0108] Embodiment 21 . The cosmetic composition or use of any one of Embodiments 1 -20, wherein the biodegradable microparticles have a butyric acid content of less than 100, less than 50, less than 20, less than 10, less than 7.5, less than 5, less than 2.5, or less than 1 ppmw, wherein the biodegradable microparticles have an acetic acid content of less than 500, less than 300, less than 100, less than 50, less than 20, less than 10, less than 7.5, less than 5, less than 2.5, or less than 1 ppmw.

[0109] Embodiment 22. The cosmetic composition or use of to any one of Embodiments 1 -21 , wherein the biodegradable microparticles exhibit at least 60 percent biodegradability at 60 days according to at least one of the OECD 301 B, OECD 301 C, or OECD 301 F test methods.

[0110] Embodiment 23. The cosmetic composition or use of any one of Embodiments 1 -22, wherein the biodegradable microparticles further comprise at least one organic acid salt.

[0111] Embodiment 24. The cosmetic composition of Embodiment 23, wherein the at least one organic acid salt comprises an alkali metal cation or an alkaline metal cation.

[0112] Embodiment 25. The cosmetic composition of Embodiment 24, wherein the alkali metal cation is Li+, Na+, or K+, and the alkaline metal cation is Mg2+or Ca2+.

[0113] Embodiment 26. The composition of any one of Embodiments 23-25, wherein the organic acid component of the at least one organic acid salt is derived from a compound of formula I wherein: G is a (Ci-

[0114] 8)alkylene, wherein the alkylene is unsubstituted or substituted by 1 to 2 hydroxyl substituents, a (Ci-8)alkenyl, or a phenyl; and n is 0, 1 , or 2.

[0115] Embodiment 27. The cosmetic composition of any one of Embodiments 23-26, wherein the compound of formula I is glutaric acid, pimelic acid, azelaic acid, sebacic acid, suberic acid, adipic acid, succinic acid, citric acid, tartaric acid, fumaric acid, terephthalic acid, isophthalic acid, acetic acid, or propionic acid, or lactic acid.

[0116] Embodiment 28. The cosmetic composition or use of any one of Embodiments 23-27, wherein the organic acid salt is sodium succinate, potassium succinate, magnesium succinate, calcium succinate, sodium citrate, potassium citrate, magnesium citrate, calcium citrate, sodium acetate, potassium acetate, magnesium acetate, calcium acetate, sodium lactate, potassium lactate, magnesium lactate, or calcium lactate.

[0117] Embodiment 29. The cosmetic composition or use of any one of Embodiments 23-28, wherein the organic acid salt is sodium succinate, potassium succinate, magnesium succinate, or calcium succinate

[0118] EXPERIMENTS

[0119] Abbreviations

[0120] Ex is example(s), F is Formulation, BuOH is butyric acid, Mg(OAc)2 is magnesium acetate, BuC>2 is butyric anhydride, AC2O is acetic anhydrice, AcOH is acetic acid, RPM is revolutions per minute; min is minute(s),

[0121] General Procedure for Preparation of Cellulose Esters

[0122] Cellulose mixture [cellulose and AcOH] (“Cellulose Mixture”) and sulfuric acid, AC2O and BU2O (“Acylation Solution”) was cooled to 30°C in an agitated reactor, and the reaction mixture cooled to around 7°C with agitation. Additional sulfuric acid was added to a target amount, and the resulting reaction mixture, while stirring, was warmed to 45 °C - 65°C until the acylation was complete and the desired molecular weight was attained. The reaction mixture treated with aqueous AcOH and BuOH (“Hydrolysis Solution”) and stirred at 68°C under the Hydrolysis Conditions. Then, the reaction mixture was then quenched, neutralized, precipitated, washed and dried by common methods.

[0123] Ex A and Ex B were synthesized using the conditions and reagents shown in Table 1 .

[0124] Table 1.

[0125] Table 2 provides several cellulose mixed esters used to prepare microbeads. Ex 1 is obtained by blending Ex A and Ex B to achieve a MW of 81 ,000.

[0126] Table 2.

[0127] Degree of Substitution

[0128] The degree of substitution for the substituents on the cellulose ester backbone is calculated using proton nuclear magnetic resonance spectroscopy. Gel permeation chromatography is performed on cellulose esters in stabilized tetrahydrofuran. The instrument is an Agilent 1260 which consists of a degasser, isocratic pump with a flow rate of 1 .0 milliliters per minute, autosampler with an injection volume of 25 microliters, a column oven set at 28°C and a refractive index detector at 28°C. The column set consists of an Agilent PLgel 5 micron guard, Mixed-C and Oligopore in series. The system is calibrated with monodisperse polystyrene standard ranging from approximately 4 million to 162 molecular weight. The sample is prepared by weighing approximately 25 milligrams of sample in 10 milliliters of solvent with the addition of 10 microliters of toluene to be used as a flow rate marker, add a stir bar into an 8-dram screw cap vial and stir until dissolution.

[0129] Molecular Weight

[0130] The molecular weight is determined by gel permeation chromatography. Gel permeation chromatography is performed on cellulose esters in stabilized tetrahydrofuran. The instrument is an Agilent 1260 which consists of a degasser, isocratic pump with a flow rate of 1 .0 milliliters per minute, autosampler with an injection volume of 25 microliters, a column oven set at 28°C and a refractive index detector at 28°C. The column set consists of an Agilent PLgel 5 micron guard, Mixed-C and Oligopore in series. The system is calibrated with monodisperse polystyrene standard ranging from approximately 4 million to 162 molecular weight. The sample is prepared by weighing approximately 25 milligrams of sample in 10 milliliters of solvent with the addition of 10 microliters of toluene to be used as a flow rate marker, add a stir bar into an 8-dram screw cap vial and stir until dissolution.

[0131] JET MILLED CE MICROPARTICLES

[0132] The CE microparticles of the present application can also be prepared by jet milling. There are multiple jet-milling configurations that can be used to reduce the size of particles. Such configurations are discussed in A. Chamayou and J. A. Dodds, Air Jet Milling, Handbook of Powder Technology, volume 12, Chapter 8, 2007 (“Chamayou”). Fig. 7 of Chamayou provides an example of a fluidized bed opposed jet mill that can be used to reduce the size of the cellulose ester particles described below in Table 3. The jet-milling process was used to reduce cellulose ester average particle size from 300- 900 pm to ~10pm. Fluidized bed opposed jet mills operates as follows: The cellulose ester is placed into a hopper and introduced into the top of the mill (“FEED IN”) typically though a double valve arrangement (or through an injector). The cellulose ester particles fall by gravity to the bottom of the mill where they are swept up into one of three high pressure air streams that are geometrically oriented towards one another thus forming the so-called “pulverizing zone.” Within the pulverizing zone, the cellulose ester particles are size reduced via interparticle collisions. The size-reduced particles are then conveyed upwards by mass transport in the vertical airstream (fluidized bed) ultimately carrying them into the classifier. The classifier allows particles below the desired minimum size to be removed from the mill (“FINE OUT”). Particles that are above the maximum size are excluded from the classifier and returned to the fluidized bed eventually falling back down into the pulverizing zone for further size reduction. Particles that fall within the desired size range are ejected from the classifier into an appropriate product container. Many control parameters exist for optimizing productivity, particle size and particle size distribution shape, including but not necessarily limited to, classifier rotor speed, air nozzle pressure, and bed level. United State Patent Application No. 63 / 491626 which is hereby incorporated by reference further provides further details for preparing jet milled microparticles.

[0133] Example 1-1

[0134] Using a jet mill, Ex 1-1 is produced starting from Ex 1. The particle size distribution of Ex 1-1 is as follows, a D(10) of 3.0 microns, a D(50) of 9.5 microns, and a D(90) of 17.7 microns, average particle size is 11.2 microns, BET Surface Area is 3.18 m2 / g, Oil Absorption (Olive Oil) is 108 g / 100g.

[0135] Example 1-2

[0136] A 1.4 wt% aqueous magnesium succinate solution (35.7 g) is added to Ex 1-1 (14.3 g) to make a slurry (50 g). The slurry is then dried in an oil-jacketed sigma-blade mixer with stirring (50 rpm, 75°C, 400 mmHg) for 16 h to yield Ex 1-2 with a calculated magnesium succinate content of 10,000 ppm.

[0137] Oil Absorption Method

[0138] Oil absorption was measured using an ASTM D281 standard test method to determine the oil absorption capacity of microparticles. In this method a known amount of microbeads was weighed in a glass vial and olive oil was carefully added drop by drop to the absorbing microparticle with a plastic pipette. The powder was thoroughly mixed with oil after addition of every other droplet by rubbing with a sharp-edged steel spatula. The test is complete when exactly enough oil has been incorporated with the particle to produce very stiff putty-like paste which does not break and separate. The dropping bottle containing oil is accurately weighed. The oil absorption capability or uptake of the microbeads is calculated by the following equation: where A = initial weight of the dropping bottle with oil, B = final weight of the dropping bottle with oil, and W = weight of the microbead sample in grams. Oil Absorption (g / g) = (A - B) / W.

[0139] BET Surface Area

[0140] Gas Adsorption BET Method - ISO 9277 was used to determine the BET surface area. The instrument used is Micromeritics ASAP 2020 instrument. A summary of the procedure follows: 1 . 0.5-1 gram samples are degassed at 60C overnight. If degassing is not sufficient, temperature will raise 10°C higher, but lower than 100°C to avoid irreversible change of the surface. 2. Sample mass is collected by the weight difference of the empty sample tube and the sample tube filled with sample after degassing. 3. Krypton adsorption at 77K is used for the specific surface area analysis. 4. Seven relative pressures from 0.06 to 0.20 are collected and fitted for BET specific surface area analysis. Note: The amount of sample is dependent on specific need and the level of moisture in them. In-vitro SPF Testing:

[0141] In-vitro SPF test of sunscreen formulations were conducted at an external lab, IMS, FL. In vitro test protocols all generally involve applying a layer of sunscreen to an artificial substrate, VITRO-SKIN exposing it to UVR from a solar simulator and measuring the UVR transmittance through the product and film by spectrophotometry (Labsphere in-vitro sunscreen analyzer).

[0142] Test Formulations Control and test formulations used for SPF testing are shown in Table

[0143] 3. The control formulation contains zinc oxide as an inorganic UV filter. SPF boosting efficacy was tested for Ex 1-1 , Nylon-12 (Kobo SP-10), PMMA (Kobo MSP-822) and silica (AGC Solesphere H-53 or Sunsphere H-53), each added to the control formulation at a 3wt% level.

[0144] Table 3. Formulation details Formulation Preparation

[0145] Combine phase B (oil phase) and mix with overhead stirrer using a large dissolver at 400 RPM. Heat oil phase to 50°C. Combine phase C (water phase) and stir with magnetic stir bar until mixed well. Add Zinc Oxide dispersion (phase A) to oil phase. Once phase A is mixed well into Phase B, transfer to Silverson Mixer and mix at 5K RPM for 5 minutes. Slowly add phase C-D to phase A-B while mixing with Silverson (10K RPM). Homogenize for 10 minutes at 10K RPM. Post-add phase E (microparticles) while mixing with Silverson at 10K RPM.

[0146] SPF Measurement Procedure

[0147] SPF measurement involved spreading the sunscreen product (2 mg / cm2) on VitroSkin artificial substrate, which mimics surface properties of human skin. The product was spread evenly onto the VitroSkin and allowed to dry for 15 min before measuring the UVR transmittance through the product and film with the Labsphere UV-1000 (Ultraviolet Transmittance Analyzer) and the sun protection factor (SPF) value was recorded. Two pieces of VitroSkin and five scans per skin were made, for a total of ten measurements.

[0148] Results

[0149] Ex 1-1 was tested in a sunscreen formulation containing an inorganic UV filter, ZnO and were found to enhance SPF by 65% compared to the same sunscreen formulation but without Ex 1-1 . Also, Ex 1-1 offered dramatically higher SPF boosting compared to Nylon-12, PMMA and silica microparticles as shown in Table 4.

[0150] Table 4.

[0151] The microparticles were added to two commercial sunscreens to determine whether the sunscreens would exhibit SPF boosting. Blue Lizard Mineral Suncreen (“CS1”) is formulated with titanium dioxide (8wt%) and zinc oxide (10wt%). Jack Black Double-Duty Face Moisturizer (“CS2”) is formulated with avobenzone (2.2wt%) and octinoxate (7.5wt%). The micropowders were formulated into the commercial suncreens at 3wt% to asses the SPF boosting efficacy of the micropowders. Table 5 shows that the samples including either Ex 1-1 or Ex 1-2 exhibited at least a 25% increase in

[0152] SPF relative to those without the micropowders.

[0153] Table 5.

Claims

What is claimed is:1 . A cosmetic composition comprising:(1 ) biodegradable microparticles, wherein the biodegradable microparticles comprise a cellulose ester, wherein:(a) the biodegradable microparticles exhibit at least 30 percent biodegradability at 60 days according to at least one of the OECD 301 B, OECD 301 C, or OECD 301 F test methods, and(b) the biodegradable particles are formed by mechanical milling; and(2) at least one UV filter agent other than the biodegradable microparticles, wherein the cosmetic composition exhibits a sun protection factor (“SPF”) value, and wherein the SPF value is at least 10% higher than a cosmetic composition comprising a UV filter agent without the biodegradable microparticles.

2. The cosmetic composition of claim 1 , wherein the at least one UV filter agent is an organic UV filter agent, an inorganic UV filter agent, or a combination thereof.

3. The cosmetic composition of any one of claims 1 -2, wherein the organic UV filter agent is dioxybenzone, di hydroxyacetone, menthyl anthranilate, benzophenone-4, benzophenone-4,octocrylene, octylsalicylate, triethanolamine salicylate, cinoxate, oxybenzone, octocrylene, Digalloyl trioleate, p-dimethylacetic acid amyl, octyl methoxycinnamate, diethanolamine p-methoxycinnamate, diethanolamine p-methoxycinnamate, Ethylmethoxycinnamate, p-aminobenzoic acid (“PABA”), glyceryl PABA, ethyldihydroxypropyl PABA, octylmethoxycinnamate, p-aminobenzoic acid, glycerylPABA, 2-phenylbenzimidazole-5-sulphonic acid, octyldimetyl PABA, 2- phenylbenzimidazole-5-sulphonic acid, homosalate, drometrizole, Butylmethoxydibenzoylmethane, octyltriazone, 3-(4-methylbenzylitene)-camphor, butylmethoxydibenzoylmethane, octyltriazone, 3-(4- methylbenzylitene)-camphor, 4-methylbenzylidene camphor, 3- benzylidenecamphor, camphorbenzalkonium, 4-methylbenzylidene camphor, triethoxycaprylylsilane, Sulphobenzylidene camphor, sulphomethylbenzylidene camphor, or combinations thereof.

4. The cosmetic composition of any one of claims 2 or 3, wherein the inorganic UV filter agent is titanium dioxide, zinc oxide, iron oxide, zirconium oxide, silicon dioxide, manganese oxide, aluminum oxide, cerium oxide, mica, silica, talc, kaolin, or combinations thereof.

5. The cosmetic composition of any one of claims 1 -4, wherein the cosmetic composition comprises at least 0.1 , at least 0.5, at least 1 , at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10, at least 11 , at least 12, at least 13, at least 14, or at least 15 weight percent of the biodegradable microparticles.

6. The cosmetic composition of any one of claims 1 -5, wherein the cosmetic composition comprises less than 99, or less than 90, or less than 80, or less than 70, or less than 60, or less than 50, or less than 40, or less than 30, or less than 25, or less than 20, or less than 15, or less than 10, or less than 5 weight percent of the biodegradable microparticles.

7. The cosmetic composition of any one of claims 1 -6, wherein the cosmetic composition is a foundation, a sunscreen, a lipstick, a lip balm, a chapstick, a mascara, an eye shadow, a lotion, a dry shampoo, a lotion, a hair conditioner, or a skin moisturizer.

8. The cosmetic composition according to any one of claims 1-7, wherein the cosmetic composition comprises at least 1 , at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, or at least 95 weight percent and / or less than 99, less than 95, less than 90, less than 85, less than 80, less than 75, less than 70, less than 65, or less than 60 weight percent of at least one, two, three, four, or five cosmetic additives, wherein the cosmetic additives comprise a colorant, an oil, a wax, a fatty acid, an alcohol, an ester, a hydrocarbon, a silicone oil, a surfactant, a metal soap, a moisturizer, a thickener, a UV absorber, an antioxidant, an oil absorbent, an exfoliant, water, or a combination thereof.

9. Use of biodegradable microparticles as a sun protection factor (“SPF”) booster in a cosmetic composition, wherein:(a) the biodegradable microparticles comprise a cellulose ester,(b) the biodegradable microparticles exhibit at least 30 percent biodegradability at 60 days according to at least one of the OECD 301 B, OECD 301 C, or OECD 301 F test methods, and(c) the biodegradable particles are formed by mechanical milling.

10. The cosmetic composition or use of any one of claims 1 -9, wherein the mechanical milling is performed by a jet mill.11 . The cosmetic composition or use of any one of claims 1-10, wherein the cellulose ester comprises:(i) a plurality of acetyl substituents; and(ii) a plurality of hydroxyl substituents, wherein cellulose ester exhibits:(1) an average degree of substitution for acetyl substituents (“DSAC”) in the range of from 0.1 to 2.5, and(2) an average degree of substitution for hydroxyl substituents (“DSOH”) in the range of 0.5 to 2.8.

12. The cosmetic composition or use of claim 11 , wherein the cellulose ester further comprises a plurality of (C3-4)alkyl-CO- substituents, and wherein the cellulose ester further exhibits: (3) an average degree of substitution for (C3- 4)alkyl-CO- (“DSAkco”) in the range of from 0.1 to 1.5.

13. The cosmetic composition or use of any one of claims 1 -12, wherein the cellulose ester is a cellulose acetate, a cellulose acetate propionate, or a cellulose acetate butyrate.

14. The cosmetic composition or use of any one of claims 10-13, wherein the DSOH is in the range of from 0.6 to 1 .0.

15. The cosmetic composition or use of any one of claims 1 -14, wherein the biodegradable microparticles exhibit a monomodal particle size distribution with a span of at least 0.5, at least 0.55, at least 0.60, at least 0.65, at least 0.70, at least 0.75, at least 0.80, at least 0.85, at least 0.9, at least 0.95, at least 1.0, at least 1 .05, at least 1 .1 , at least 1.15, at least 1.2, or at least 1 .25 and / or less than 3.0, less than 2.9, less than 2.8, less than 2.7, less than 2.6, less than 2.5, less than 2.4, less than 2.3, less than 2.2, less than 2.1 , less than 2.0, less than 1 .9, less than 1 .8, less than 1 .7, or less than 1 .6, and wherein the biodegradable microparticles have a D50 particle size in the range of 1 to 20, or 1 to 18, or 1 to 16, or 1 to 14, or 1 to 12, or 2 to 20, or 2 to18, or 2 to 16, or 2 to 14, or 2 to 12, or 4 to 20, or 4 to 18, or 4 to 16, or 4 to14, or 4 to 12, or 6 to 20, or 6 to 18, or 6 to 16, or 6 to 14, or 6 to 12, or 8 to20, or 8 to 18, or 8 to 16, or 8 to 14, or 8 to 12 microns.

16. The cosmetic composition or use of any one of claims 1 -15, wherein the biodegradable microparticles have a polydispersity index of less than 0.8, less than 0.7, less than 0.6, less than 0.5, less than 0.4, or less than 0.3.

17. The cosmetic composition or use of any one of claims 1-16, wherein the biodegradable microparticles have a sphericity of less than 80, or of less than 75, or of less than 70, or of less than 65, or of less than 60, or of less than 55 percent.

18. The cosmetic composition or use of any one of claims 1-17, wherein the biodegradable microparticles have an average smoothness of at least 10, 20, 30, 40, 50, 60, 70, 80, 90, 95, 95, 97, 98, or 99 percent and / or not more than 99, 95, 90, 80, 70, 60, 50, 40, 30, 20, or 10 percent.

19. The cosmetic composition or use of any one of claims 1 -18, wherein the biodegradable microparticles exhibit an oil absorption of at least 30 mL per100 g at least 35 mL per 100 g, at least 40 mL per 100 g, at least 45 mL per 100 g, at least 50 mL per 100 g, at least 55 mL per 100 g, or at least 60 mL per 100 g as measured using test method ASTM D281 , wherein mineral oil is used instead of castor oil.

20. The cosmetic composition or use of any one of claims 1 -19, wherein the biodegradable microparticles have an average BET surface area in the range of 0.1 to 100 m2 / g as measured according to ISO 9277 using a Micromeritics ASAP 2020 instrument and krypton gas.21 . The cosmetic composition or use of any one of claims 1-20, wherein the biodegradable microparticles have a butyric acid content of less than 100, less than 50, less than 20, less than 10, less than 7.5, less than 5, less than 2.5, or less than 1 ppmw, wherein the biodegradable microparticles have an acetic acid content of less than 500, less than 300, less than 100, less than 50, less than 20, less than 10, less than 7.5, less than 5, less than 2.5, or less than 1 ppmw.

22. The cosmetic composition or use of any one of claims 1 -21 , wherein the biodegradable microparticles exhibit at least 60 percent biodegradability at 60 days according to at least one of the OECD 301 B, OECD 301 C, or OECD 301 F test methods.

23. The cosmetic composition or use of any one of claims 1 -22, wherein the biodegradable microparticles further comprise at least one organic acid salt.

24. The cosmetic composition of claim 23, wherein the at least one organic acid salt comprises an alkali metal cation or an alkaline metal cation.

25. The cosmetic composition of claim 24, wherein the alkali metal cation is Li+, Na+, or K+, and the alkaline metal cation is Mg2+or Ca2+.

26. The composition of any one of claims 23-25, wherein the organic acid component of the at least one organic acid salt is derived from a compound of formula I:wherein:G is a (Ci-8)alkylene, wherein the alkylene is unsubstituted or substituted by 1 to 2 hydroxyl substituents, a (Ci-8)alkenyl, or a phenyl; and n is 0, 1 , or 2.

27. The cosmetic composition of any one of claims 23-26, wherein the compound of formula I is glutaric acid, pimelic acid, azelaic acid, sebacic acid, suberic acid, adipic acid, succinic acid, citric acid, tartaric acid, fumaric acid, terephthalic acid, isophthalic acid, acetic acid, or propionic acid, or lactic acid.

28. The cosmetic composition or use of any one of claims 23-27, wherein the organic acid salt is sodium succinate, potassium succinate, magnesium succinate, calcium succinate, sodium citrate, potassium citrate, magnesium citrate, calcium citrate, sodium acetate, potassium acetate, magnesium acetate, calcium acetate, sodium lactate, potassium lactate, magnesium lactate, or calcium lactate.

29. The cosmetic composition or use of any one of claims 23-28, wherein the organic acid salt is sodium succinate, potassium succinate, magnesium succinate, or calcium succinate.

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