Water-soluble zinc hydroxychloride compositions and methods of making the same

Abstract

A personal care composition may include a water-soluble zinc hydroxychloride having a chemical formula Zn(OH)2-xClx, where x is from 0.67 to 1.89. The personal care composition may further include glycine. The personal care composition may be an antiperspirant or a deodorant. The water-soluble zinc hydroxychloride may be made by a method including reacting zinc chloride with a base to form a reaction product comprising the water-soluble zinc hydroxychloride. The water-soluble zinc hydroxychloride may also be made by a method including reacting zinc oxide or a water-insoluble zinc hydroxide with an acid to form a reaction product comprising the water-soluble zinc hydroxychloride.

Description

GULBRA 3.4-013WATER-SOLUBLE ZINC HYDROXYCHLORIDE COMPOSITIONS AND METHODS OF MAKING THE SAME CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority to United States Provisional Patent Application No.63 / 739,874, filed on December 30, 2024, the disclosure of which is incorporated herein by reference in its entirety.TECHNICAL FIELD

[0002] The present disclosure is directed to water-soluble zinc hydroxychloride compositions and methods of making the same. The water-soluble zinc hydroxychloride compositions may have deodorizing and sweat reduction properties.BACKGROUND

[0003] The skin microbiome is the cause of body odor, and deodorants are designed to reduce or prevent underarm odor. Deodorants may use various active ingredients that employ different mechanisms of action. For example, odor absorbers can either bind or eliminate volatile odor components while odor-covering agents simply cover odor. Antimicrobial agents and enzyme inhibitors directly influence the bacteria and prevent the degradation of the organic body products. Antiperspirants, on the other hand, reduce the formation of moisture by temporarily blocking the sweat glands. Conventional Al and ALZr based antiperspirants tend to be acidic in an aqueous solution, which makes them effective as antimicrobial agents, thereby providing a deodorant benefit.

[0004] The safety of aluminum salts in deodorants has been discussed controversially. Although there is no scientific evidence of negative health impacts caused by the absorption of aluminum from deodorants into the body, consumers remain skeptical about aluminum salts in deodorants. As a result, the demand for aluminum-free deodorants is growing.

[0005] In the deodorant sector, there is an increasing demand for natural ingredients. Although plant extracts and essential oils can both act as antimicrobial agents and provide a pleasing smell, those ingredients may not suit individuals with strong body odor or hyperhidrosis patients. Moreover, the use of plant extracts and essential oils in deodorant or antiperspirant products might be limited by their country / region of origin and their availability. While some plant extract or essential oil deodorizing agents may have shown excellent antimicrobial activity towards human natural microflora, it is crucial for those ingredients to be compared to commercially available products and be subjected to a sensory assessment, as the one of the aims of deodorants and antiperspirant products is to reduce the axilla odor intensity. It should be noted that a large-scale production of deodorant with plant extracts or essential oils can be a challenging and costly process. Extraction processes often require a large volume of solvent and long extraction time. Lastly, the general concerns of most antimicrobials are that they can lead to resistant bacterial strains being developed, making the product less effective over a long period.

[0006] The use of zinc in deodorants plays an important role in many different biological processes. Elemental zinc and its salts have long been used in topical preparations for therapeutic purposes and their anti-GULBRA 3.4-013inflammatory and wound-healing properties have been confirmed in many different studies. Zinc salts are also popular ingredients for daily-use skin care products because of their skin-conditioning and soothing effects.

[0007] Besides the properties mentioned above, zinc salts are also known to have an antimicrobial effect which makes them likely candidates as active ingredients for deodorants. Zinc salts are already known to act as odor absorbers and are used in this function in deodorants to obtain a longer-lasting effect. Organic zinc salts are usually used for this application. The odor absorbing effect may be the result of the high reactivity of the zinc ion with sulfur and amine groups in the low-molecular- weight organic compounds that are produced by the bacteria.

[0008] Water-insoluble zinc compounds such as zinc hydroxy chloride, zinc oxide, and zinc polycarboxylic acids can be used as deodorants through odor absorbing mechanisms. The chemical formula of the waterinsoluble zinc hydroxy chloride is commonly represented as Zm OHjsCb- H2O. It is a type of basic zinc chloride salt as it contains both hydroxide (OH ) and chloride (CH) ions. It appears as a white or pale-yellow crystalline powder and is categorized as a basic zinc salt. There are major two drawbacks for the waterinsoluble zinc compounds. The first drawback is a low Zn2+concentration resulting in limited absorbing property. The second drawback is their insolubility in water, which makes it difficult to formulate them in water-based compositions, which are often used in cosmetics.

[0009] Zinc chloride had a reputation as a deodorant and disinfectant for many years due to its high solubility in water that provides a high concentration of Zn2+ions. Compared to zinc chloride, organic zinc salts have a much lower Zn2+concentration, resulting in reduced deodorant properties. However, zinc chloride is highly irritant, which limits its application in the personal care industry. Many attempts have been carried out to reduce the irritancy of zinc chloride. The most common method is through neutralization of zinc chloride by a base such as sodium hydroxide or sodium carbonate. A water-insoluble compound of zinc hydroxychloride is quickly formed in this process. There is much literature on making water-insoluble zinc hydroxychloride and their applications as deodorants. Since such zinc hydroxychloride compounds are water-insoluble, a very low concentration of Zn2+is present in the aqueous solution, which results in relatively low deodorant properties of such complexes.SUMMARY

[0010] Accordingly, there is a need for improved zinc hydroxychloride compositions that are water soluble and provide improved deodorant and antiperspirant properties.

[0011] Aspects of the present disclosure are directed to a personal care composition comprising a water-soluble zinc hydroxy chloride having the chemical formula Zn(OH)2-xClx, wherein x is from 0.67 to 1.89.

[0012] Aspects of the present disclosure are directed to a method of making a water-soluble zinc hydroxychloride, the method comprising reacting zinc chloride with a base to form a reaction product comprising the water-soluble zinc hydroxychloride, wherein the water-soluble zinc hydroxychloride has a chemical formula Zn(OH)2-xClx, wherein x is from 0.67 to 1.89.

[0013] Aspects of the present disclosure are directed to a method of making a water-soluble zinc hydroxychloride, the method comprising reacting zinc oxide or a water-insoluble zinc hydroxide with an acidGULBRA 3.4-013to form a reaction product comprising the water-soluble zinc hydroxychloride, wherein the water-soluble zinc hydroxychloride has a chemical formula Zn(OH)2-xClx, wherein x is from 0.67 to 1.89.

[0014] As described in more detail herein, when adding a base such as sodium hydroxide to a zinc chloride aqueous solution, a precipitate is quickly formed. Surprisingly, the precipitate is re-dissolved upon addition of an amino acid, such as glycine, and a clear soludon is formed. As the amount of glycine added to the solution is increased, the basicity of water-soluble zinc hydroxy chloride solution increases. Even more surprisingly, when ammonium hydroxide is added to a zinc chloride solution, a clear colorless water-soluble zinc hydroxychloride solution is formed without the presence of an amino acid, such as glycine. The resultant water-soluble zinc hydroxychloride is non-irritant, highly antibacterial, antimicrobial, and antifungal, demonstrates strong deodorant properties and has high sweat-reduction properties.DETAILED DESCRIPTION

[0015] Aspects of the present disclosure are directed to personal care compositions comprising a water-soluble zinc hydroxychloride. The water-soluble zinc hydroxychloride may produce an increased amount of zinc ions in an aqueous solution, similar to zinc chloride. This may result in antibacterial, antimicrobial, and antifungal properties. A personal care composition comprising the water-soluble zinc hydroxychloride may be non-irritant and skin friendly, unlike a personal care composition using zinc chloride. The antibacterial, antimicrobial, and antifungal properties of the water-soluble zinc hydroxychloride make the water-soluble zinc hydroxychloride a good candidate for antidandruff, anti-acne, hand soap, body wash, oral care, home care and pet care applications.

[0016] Underarm deodorants control odor by eliminating the bacteria that cause the odor. Due to its antibacterial, antimicrobial, and antifungal properties, the water-soluble zinc hydroxychloride according to one or more aspects of the present disclosure demonstrates strong deodorant properties. For example, at 3% zinc concentration by weight, a personal care composition comprising the water-soluble zinc hydroxychloride demonstrates underarm deodorant properties for about 72-hours, as described in detail in the experimental examples hereinbelow.

[0017] Personal care compositions comprising the water-soluble zinc hydroxychloride according to one or more aspects of the present disclosure may have strong sweat reduction properties. In comparison to aluminum-based antiperspirant, such as an aluminum chlorohydrate antiperspirant, a water-soluble zinc hydroxychloride antiperspirant may have similar or improved sweat reduction properties, as described in more detail in the experimental examples hereinbelow.

[0018] In one or more aspects, the personal care composition may be a skincare product. For example, the personal care composition may be an antiperspirant or a deodorant. In some aspects, the personal care composition may be a whole body deodorant. In one or more aspects, the personal care composition may be a shampoo, a hair conditioner, a body wash, a shower gel, or a bar soap. In some aspects, the personal care composition may be an oral care product. In some aspects, the personal care composition may be a home care product. In some aspects, the personal care composition may be a pet care product. The formulation of theGULBRA 3.4-013personal care composition is not necessarily limited. For example, the personal care composition may be an aerosol, a gel, a cream, a spray, a stick formulation, or a roll-on formulation.

[0019] In one or more aspects, the water-soluble zinc hydroxychloride according to one or more aspects of the present disclosure may be used as actives for home care and pet care.

[0020] The personal care composition may comprise a water-soluble zinc hydroxychloride. In one or more aspects, the water-soluble zinc hydroxychloride may be in an aqueous soludon in the personal care composition. The water-soluble zinc hydroxychloride may have the chemical formula Zn(OH)2-xClx. In one or more aspects, x may have a value from 0.67 to 1.89. For example, x may have a value from 0.67 to 1.89, from 0.7 to 1.89, from 0.8 to 1.89, from 0.9 to 1.89, from 1.0 to 1.89, from 1.1 to 1.89, from 1.2 to 1.89, from 1.3 to 1.89, from 1.4 to 1.89, from 1.5 to 1.89, from 1.6 to 1.89, from 1.7 to 1.89, from 1.8 to 1.89, from 0.67 to 1.8, from 0.67 to 1.7, from 0.67 to 1.6, from 0.67 to 1.5, from 0.67 to 1.4, from 0.67 to 1.3, from 0.67 to 1.2, from 0.67 to 1.1, from 0.67 to 1.0, from 0.67 to 0.9, from 0.67 to 0.8, or any range formed from any combination of these endpoints. In some aspects, x may have a value from 0.77 to 1.43 or from 0.83 to 1.25. Without intending to be bound by theory, if the value of x is too low (i.e., less than 0.67), then the water-soluble zinc hydroxychlroide may be too acidic and may cause skin irritancy. If the value of x is to great (i.e., greater than 1.89), then the zinc hydroxychloride may be water insoluble and may be less effective as an antiperspirant or deodorant than a water-soluble zinc hydroxychloride.

[0021] In one or more aspects, the personal care composition may comprise glycine. A molar ratio of glycine to zinc may be from 0.5 to 2.5. For example, the molar ratio of glycine to zinc may be from 0.5 to 2.5, from 0.7 to 2.5, from 0.9 to 2.5, from 1.1 to 2.5, from 1.3 to 2.5, from 1.5 to 2.5, from 1.7 to 2.5, from 1.9 to 2.5, from 2.1 to 2.5, from 2.3 to 2.5, from 0.5 to 2.4, from 0.5 to 2.2, from 0.5 to 2.0, from 0.5 to 1.8, from 0.5 to 1.6, from 0.5 to 1.4, from 0.5 to 1.2, from 0.5 to 1.0, from 0.5 to 0.8, or any range formed from any combination of these endpoints. In some aspects, the molar ratio of glycine to zinc may be from 0.8 to 2.0, or from 1.0 to 1.6. Without intending to be bound by theory, the inclusion of glycine in the personal care composition may reduce irritancy of the personal care composition. For example, if the amount of glycine in the composition is too low, i.e., the molar ratio of glycine to zinc is less than 0.5, then the irritancy of the personal care composition may be increased. Additionally, if the amount of glycine in the personal care composition is too great, i.e., the molar ratio of glycine to zinc is greater than 2.5, then the sweat reduction properties of the personal care composition may be reduced.

[0022] In one or more aspects, the molar ratio of zinc to chlorine in the personal care composition may be from 0.53 to 1.5. For example, the molar ratio of zinc to chlorine may be from 0.53 to 1.5, from 0.6 to 1.5, from 0.7 to 1.5, from 0.8 to 1.5, from 0.9 to 1.5, from 1.0 to 1.5, from 1.1 to 1.5, from 1.2 to 1.5, from 1.3 to 1.5, from 1.4 to 1.5, from 0.53 to 1.4, from 0.53 to 1.3, from 0.53 to 1.2, from 0.53 to 1.1, from 0.53 to 1.0, from 0.53 to 0.9, from 0.53 to 0.8, from 0.53 to 0.7, from 0.53 to 0.6, or any range formed from any combination of these endpoints. In some aspects, the molar ratio of zinc to chlorine may be from 0.7 to 1.3 or from 0.8 to 1.2.

[0023] Without intending to be bound by theory, the molar ratio of zinc to chlorine may be related to the quantity of glycine used to form the water-soluble zinc hydroxychloride. As the amount of glycine used duringGULBRA 3.4-013the formation of the water-soluble zinc hydroxychloride is increased, the molar ratio of zinc to chlorine is also increased. If the molar ratio of zinc to chlorine is too low (less than 0.53), then the personal care composition may demonstrate skin irritancy even when the pH is relatively high, such as 5 or above. If the molar ratio of zinc to chlorine is too high (greater than 1.5) then the insoluble precipitates may form, reducing the amount of Zn2+ions in solution, which in turn may reduce deodorant properties and sweat reduction properries of the personal care composition.

[0024] The personal care composition may comprise one or more amino acids in addition to glycine. In one or more aspects, the personal care composition may comprise glycine and one or more of alanine, arginine, asparagine, cysteine, glutamine, histidine, leucine, lysine, methionine, phenylalanine, proline, serine, tryptophan, tyrosine, or valine. The amino acids can be used alone or combined with glycine. In one or more aspects, the personal care composition may comprise L-arginine. The weight ratio of glycine to L-arginine may be from 50:50 to 90:10. For example, the weight ratio of glycine to L-arginine may be from 50:50 to 90:10, from 60:40 to 90:10, from 70:30 to 90:10, from 80:20 to 90:10, from 50:50 to 80:20, from 50:50 to 70:30, from 50:50 to 60:40, or any range formed from any combination of these endpoints.

[0025] In one or more aspects, the personal care composition may be substantially free arginine. The personal care composition may be substantially free of betaine. The personal care composition may be substantially free of trimethylglycine. As described herein, a composition is substantially free of a constituent when the constituent is not intentionally added to the composition. Without intending to be bound by theory, the inclusion of arginine, betaine, or trimethylglycine in the personal care composition may result in a waterinsoluble zinc hydroxychloride.

[0026] In one or more aspects, a total amount of zinc in the personal care composition may be from 0.5% to 17% by weight, based on a total weight of the personal care composition. For example, a total amount of zinc in the personal care composition, by weight, may be from 0.5% to 17%, from 1% to 17%, from 2% to 17%, from 3% to 17%, from 4% to 17%, from 5% to 17%, from 6% to 17%, from 7% to 17%, from 8% to 17%, from 9% to 17%, from 10% to 17%, from 11% to 17%, from 12% to 17%, from 13% to 17%, from 14% to 17%, from 14% to 17%, from 15% to 17%, from 16% to 17%, from 2% to 16%, from 2% to 15%, from 2% to 14%, from 2% to 13%, from 2% to 12%, from 2% to 11%, from 2% to 10%, from 2% to 9%, from 2% to 7%, from 2% to 5%, or any range formed from any combination of these endpoints. In some aspects, the total amount of zinc in the personal care composition, by weight, may be from 1% to 15%, from 2% to 12%, or from 3% to 10%. Without intending to be bound by theory, when the amount of zinc in the personal care composition is within the above ranges, the personal care composition may have deodorant and / or antiperspirant properties.

[0027] The water-soluble zinc hydroxychloride may be made by any suitable method. In one or more aspects, a method of making the water-soluble zinc hydroxychloride may comprise reacting zinc chloride with a base to form a reaction product comprising the water-soluble zinc hydroxychloride. The zinc chloride may be in an aqueous solution during the reaction. The base may be in an aqueous solution during the reaction. In one or more aspects, the base may be added until the pH of the reaction product is from about 5.0 to about 7.0.GULBRA 3.4-013

[0028] In one or more aspects, the base may comprise one or more of sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, calcium oxide, calcium carbonate, magnesium hydroxide, magnesium oxide, zinc hydroxide, zinc oxide, ammonium hydroxide, urea, an amine derivative, or ethanol amine. In some aspects, the base may be sodium hydroxide or potassium hydroxide. In some aspects, the base may be ammonium hydroxide (ammonia). The amine derivative may be selected for reducing the acidity of the zinc chloride solution, and in some aspects, the amine deri vali ves may be primary amine derivatives.

[0029] The method of making the water-soluble zinc hydroxychloride may further comprise adding glycine to the reaction product. When the base, such as sodium hydroxide, is added to a zinc chloride aqueous solution, a precipitate is formed quickly. Upon addilion of glycine to the reaction product, the precipitate is redissolved and a clear, colorless solution is formed. This clear colorless solution is a water-soluble zinc hydroxychloride solution. As described hereinabove, the water-soluble zinc hydroxychloride may have the chemical composition Zn(OH)2-xClx, where x is from 0.67 to 1.89. Without intending to be bound by theory, as the amount of glycine introduced into the reaction product is increased, the amount of precipitate that is redissolved is increased. Additionally, the addilion of glycine may reduce the irritancy of a personal care composition comprising the water-soluble zinc hydroxychloride.

[0030] In one or more aspects, glycine may be added to the reaction product such that the molar ratio of glycine to zinc may be from 0.5 to 2.5. For example, the molar ratio of glycine to zinc may be from 0.5 to 2.5, from 0.7 to 2.5, from 0.9 to 2.5, from 1.1 to 2.5, from 1.3 to 2.5, from 1.5 to 2.5, from 1.7 to 2.5, from 1.9 to 2.5, from 2.1 to 2.5, from 2.3 to 2.5, from 0.5 to 2.4, from 0.5 to 2.2, from 0.5 to 2.0, from 0.5 to 1.8, from 0.5 to 1.6, from 0.5 to 1.4, from 0.5 to 1.2, from 0.5 to 1.0, from 0.5 to .8, or any range formed from any combination of these endpoints. In some aspects, the molar ratio of glycine to zinc may be from 0.8 to 2.0, or from 1.0 to 1.6.

[0031] The addition of other amino acids may prevent the dissolution of the precipitate and the formation of the water-soluble zinc hydroxychloride. For example, the addilion of arginine did not result in the redissolution of the precipitate, and a water-insoluble zinc hydroxychloride was formed. Additionally, the addition of betaine or trimethylglycine did not result in the redissolution of the precipitate, and a water-insoluble zinc hydroxychloride was formed.

[0032] In one or more aspects, the ammonium hydroxide (ammonia) is the base that is reacted with the zinc chloride. When ammonium hydroxide is reacted with the zinc chloride, no precipitate is formed unli I the molar ratio of zinc to chlorine is close to 1. In such cases a clear water-soluble zinc hydroxychloride solution is formed, without the need for the addition of glycine. When the molar ratio of zinc to chlorine is greater than 1 , the reaction product is hazy and a water-insoluble zinc hydroxychloride mixture is formed and the smell of ammonia is generated. However, when glycine is added to the reaction product, a water-soluble zinc hydroxychloride soludon may be formed even when the molar ratio of zinc to chlorine is greater than 1. Without intending to be bound by theory, the zinc ion in the aqueous solution may interact with amine groups in glycine or ammonia to form the water-soluble zinc hydroxychloride.GULBRA 3.4-013

[0033] In one or more aspects, a method of making the water-soluble zinc hydroxychloride may include reacting zinc chloride with a base and an amino acid such as glycine to form a reaction product, and the reaction product may be heated to a temperature from 45 °C to 100 °C until the reaction product becomes clear.

[0034] In one or more aspects, the reaction product may be heated to a temperature from 45 °C to 100 °C. For example, the temperature may be from 45 °C to 100 °C, from 55 °C to 100 °C, from 65 °C to 100 °C, from 75 °C to 100 °C, from 85 °C to 100 °C, from 95 °C to 100 °C, from 45 °C to 95 °C, from 45 °C to 85 °C, from 45 °C to 75 °C, from 45 °C to 65 °C, from 45 °C to 55 °C, or any range formed from any combination of these endpoints. In some aspects, the reaction product may be heated to a temperature from 45 °C to 100 °C or from 65 °C to 75 °C.

[0035] In one or more aspects, a method of making the water-soluble zinc hydroxychloride may include reacting zinc oxide or a water-insoluble zinc hydroxide with an acid to form a reaction product comprising the water-soluble zinc hydroxychloride. The zinc oxide or water-insoluble zinc hydroxide may be suspended in water to form a slurry. The slurry may be heated to a temperature from 65 °C to 100 °C. The slurry may be contacted with acid under continuous hearing until the slurry becomes clear. In one or more aspects the acid may comprise one or more of hydrochloric acid, nitric acid, or sulfuric acid.

[0036] In one or more aspects, the slurry may be contacted with the acid at a temperature from 45 °C to 100 °C. For example, the temperature may be from 45 °C to 100 °C, from 55 °C to 100 °C, from 65 °C to 100 °C, from 75 °C to 100 °C, from 85 °C to 100 °C, from 95 °C to 100 °C, from 45 °C to 95 °C, from 45 °C to 85 °C, from 45 °C to 75 °C, from 45 °C to 65 °C, from 45 °C to 55 °C, or any range formed from any combination of these endpoints. In some aspects, the slurry may be contacted with the acid at a temperature from 45 °C to 100 °C or from 65 °C to 75 °C.

[0037] The method of making the water-soluble zinc hydroxychloride may comprise adding glycine to the reaction product. In some aspects, the glycine may be added to the slurry of zinc oxide or water-insoluble zinc hydroxide along with the acid.

[0038] In one or more aspects, the water-soluble zinc hydroxychloride may have the chemical formula Zn(OH)2-xClx, wherein x is from 0.67 to 1.89, as described hereinabove. In some aspects, x may have a value from 0.77 to 1.43 or from 0.83 to 1.25. Additionally, the molar ratio of zinc to chlorine in the water-soluble zinc hydroxychloride is from 0.53 to 1.5, as described hereinabove. In some aspects, the molar ratio of zinc to chlorine may be from 0.7 to 1.3 or from 0.8 to 1.2.

[0039] In one or more aspects, the reaction product comprising the water-soluble zinc hydroxychloride may be dried. The reaction product may be dried by any suitable method. For example, the reaction product may be dried by spray drying or freeze drying. In one or more aspects, a total amount of zinc, by weight, in the dried water-soluble zinc hydroxychloride, based on a total weight of the dried water-soluble zinc hydroxy chloride, may be from 18% to 40%. For example, a total amount of zinc in the dried water-soluble zinc hydroxychloride may be from 18% to 40%, from 20% to 40%, from 25% to 40%, from 30% to 40%, from 35% to 40%, from 18% to 35%, from 18% to 30%, from 18% to 25%, from 18% to 20%, or any range formed from any combination of these endpoints. In some aspects, a total amount of zinc in the dried water-soluble zinc hydroxy chloride may be from 20% to 40%, or from 25% to 35%.GULBRA 3.4-013Examples

[0040] The following examples are to further illustrate aspects of the present disclosure. It should be understood that the aspects of the present disclosure are not limited to the specific experimental examples described herein. All amounts of various ingredients are given by weight unless otherwise specified.

[0041] Zinc chloride, potassium hydroxide, and sodium hydroxide aqueous solutions were prepared with the following concentrarions. These solutions were used throughout the experimental examples described herein.

[0042] ZnCH solution: 42 parts of zinc chloride (assay: 99%) were dissolved in 58 parts of water to make 20% w / w zinc chloride (ZnCL) aqueous solution.

[0043] KOH solution: 17 parts of potassium hydroxide flakes (assay: 85%) were dissolved in 83 g water to make 10% w / w potassium hydroxide (KOH) aqueous solution.

[0044] NaOH solution: 37 parts of NaOH solution (48% NaOH solution, Lye) were dissolved in 63 parts of water to make 10% w / w NaOH aqueous solution.Example 1 - Making water-soluble zinc hydroxychloride solutions using potassium hydroxide (KOH) at a 7% Zn concentration

[0045] The water-soluble zinc hydroxychloride solutions of Examples 1A to IF were produced by the following general method. Examples 1A through IF differ in the material quantities used in the general method. The material quantities are given in Table 1-1 and the properties of the water-soluble zinc hydroxychloride solutions of Examples 1A to IF are given in Table 1-2.

[0046] A 20% ZnCL solution was charged into a glass flask, followed by the addition of water. The solution was agitated at a 300 RPM agitation speed. About 80% of the total quantity of glycine was charged into the glass flask. The pH of the solution was dropped to about 3.5 by the addition of the glycine. To this acidic solution, a 10% KOH solution was added over a period of 30 minutes at the temperature of 25 °C to 35 °C until the reaction mass became hazy. At this stage, the further addition of KOH was stopped. Subsequently, the remaining 20% of the total quantity of glycine was charged into the flask, and the solution became clear. The pH was measured at this stage. After the glycine addition, the batch was agitated for about 15 minutes.

[0047] Example 1A was a zero glycine batch, where glycine was not added into the ZnCb aqueous solution and potassium hydroxide solution was added until mild precipitation was observed. In the Example 1A, as soon as potassium hydroxide solution (1 drop, equivalent to about 0.2 g) was added, the zinc hydroxide precipitates were formed.GULBRA 3.4-013Table 1-1: Material Quantities used to prepare Examples 1A-1FTable 1-2: Properties of the water-soluble zinc hydroxychloride solutions of Examples 1A-1F*: theoretical value

[0048] In the absence of glycine, a precipitate was formed immediately upon the addition of KOH into the ZnCH solution of Example 1A. A higher glycine concentration resulted in the clear water-soluble zinc hydroxy chloride solutions with higher Zn / Cl active mole ratio at a constant zinc level.Example 2 - Making water-soluble zinc hydroxychloride solutions using potassium hydroxide (KOH) at a 5% Zn concentrationGULBRA 3.4-013

[0049] The water-soluble zinc hydroxy chloride solutions of Examples 2A-2D were prepared according to the general method previously described in Example 1. Examples 2A through 2D differ in the material quanlilics used in the general method. The material quantities are given in Table 2-1 and the properries of the water-soluble zinc hydroxychloride solutions of Examples 2A to 2D are given in Table 2-2.Table 2-1: Material Quantities used to prepare Examples 2A-2DTable 2-2: Properties of the water-soluble zinc hydroxychloride solutions of Examples 2A-2D

[0050] At a constant zinc concentration of 5%, a higher glycine level resulted in an elevated Zn / Cl mole ratio in the water-soluble zinc hydroxychloride solutions when KOH was added to the ZnCH solutions.

[0051] Example IE and Example 2B are compared in Table 2-3 below to understand the impact of water concentration in the compositions.GULBRA 3.4-013Table 2-3: Properties of the water-soluble zinc hydroxy chloride solutions of Examples IE and 2B

[0052] The water-soluble zinc hydroxychloride solution having a lower zinc concentration and a lower Zn / Cl mole ratio (Example 2B) was formed at a similar Glycine / Zn mole ratio to the water-soluble zinc hydroxychloride solulion having a greater zinc concentration (Example IE). The water-soluble zinc hydroxychloride solution having a lower zinc concentration also had a lower pH than the water-soluble zinc hydroxychloride solution having a greater zinc concentration.Example 3 - Making water-soluble zinc hydroxychloride solutions using sodium hydroxide (NaOH) at a 7% Zn concentration

[0053] The water-soluble zinc hydroxychloride solutions of Examples 3A to 3E were produced by the following general method. Examples 3A through 3E differ in the material quantities used in the general method. The material quantities are given in Table 3-1 and the properties of the water-soluble zinc hydroxychloride solutions of Examples 3A to 3E are given in Table 3-2.

[0054] A 20% ZnCE solution was charged into a glass flask. Water was added to the ZnCE solution and agitated at a 300 RPM agitation speed. 80% of the total quanlily of glycine was charged to the glass flask. The pH of the solution was dropped by addilion of glycine. To this solution, a 10% NaOH solulion was added over a period of 30 minutes at room temperature. The NaOH solution was added until the solulion became hazy. At this stage, further addition of NaOH was stopped. Subsequently, the remaining 20% of the total quantity of glycine was charged to the flask, and the solution became clear. The pH was measured at this stage. After the glycine charging, the batch was agitated for about 15 minutes to give a clear solution.

[0055] Example 3E was a zero glycine batch, where glycine was not added into the ZnCO aqueous solulion and sodium hydroxide solution was added until mild precipitation was observed. In the Example 3E, as soon as the sodium hydroxide solution (1 drop, equivalent to about 0.2 g) was added, the zinc hydroxide precipitates were formed.Table 3-1: Material Quantities used to prepare Examples 3A-3EGULBRA 3.4-013Table 3-2: Properties of the water-soluble zinc hydroxychloride solutions of Examples 3A-3E*: Theoretical value

[0056] The data in Tables 3-1 and 3-2 indicate that increasing the concentration of glycine in the formulation leads to a greater Zn / Cl mole ratio in the final water-soluble zinc hydroxychloride solution. This is similar to the phenomenon observed in the potassium hydroxide processes of Examples 1 and 2.Example 4 - Making water-soluble zinc hydroxychloride solutions using sodium hydroxide (NaOH) at a 5% Zn concentration

[0057] The water-soluble zinc hydroxy chloride soludons of Examples 4A-4D were prepared according to the general method previously described in Example 3. Examples 4 A through 4D differ in the material quantities used in the general method. The material quantities are given in Table 4-1 and the properties of the water-soluble zinc hydroxychloride solutions of Examples 4A to 4D are given in Table 4-2.GULBRA 3.4-013Table 4-1: Material Quantities used to prepare Examples 4A-4DTable 4-2: Properties of the water-soluble zinc hydroxychloride solutions of Examples 4A-4D

[0058] Like the 7% zinc concentration water-soluble zinc hydroxy chloride solutions of Example 3, the 5% zinc concentration water-soluble zinc hydroxychloride solutions of Example 4 have a higher Zn / Cl mole ratio at greater glycine concentration.

[0059] Example 2C and Example 4D are compared in Table 4-3 below to understand if similar moles of either sodium hydroxide or potassium hydroxide are required to achieve the same Zn / Cl molar ratio. The data in Table 4-3 indicates that similar moles of base are required to achieve the same Zn / Cl molar ratio.GULBRA 3.4-013Table 4-3: Properties of the water-soluble zinc hydroxy chloride solutions of Examples 2C and 4DExample 5 - Making water-soluble zinc hydroxychloride solutions using zinc oxide (ZnO), hydrochloric acid (HCl), and glycine at a 5% Zn concentration

[0060] The water-soluble zinc hydroxychloride solutions of Examples 5A to 5F were produced by the following general method. Examples 5A through 5F differ in the material quantities used in the general method. The material quantities are given in Table 5-1 and the properties of the water-soluble zinc hydroxychloride solutions of Examples 5A to 5F are given in Table 5-2.

[0061] Water was added to a round bottom flask. The water was stirred by an overhead stirrer at an agitation speed of 300 rpm, and the water was heated to 65 °C to 75 °C. Glycine was added to the water. The soludon was stirred for 10 minutes to 15 minutes. ZnO was slowly added to the solution while the temperature was maintained at 65 °C to 75 °C. A white slurry was formed upon addition of the ZnO. HCl was slowly added to the slurry until the slurry became clear, while maintaining the temperature at 65 °C to 75 °C. The resulting solution was stirred for 10 minutes to 15 minutes to obtain a clear solution. The solution was cooled to room temperature. The solution was filtered to remove some residual ZnO particles.

[0062] Example 5A was a zero glycine batch, where glycine was not added. In Example 5A, ZnO was dispersed into the water in the glass round bottom flask. The temperature was increased to 65 °C to 70°C. HCl was added by an additional glass funnel, and the mixture did not become clear. It was a slightly hazy solution compared to Examples 5B to 5F. The hazy solution was stirred at a temperature of 65 °C to 70°C for about 15 minutes. The solution was cooled to room temperature, filtered to give a clear solution, and taken for the analysis.Table 5-1: Material Quantities used to prepare Examples 5A-5FGULBRA 3.4-013Table 5-2: Properties of the water-soluble zinc hydroxychloride solutions of Examples 5A-5F*: Precipitate.

[0063] The data in Tables 5-1 and 5-2 indicates that a greater glycine concentration results in a greater Zn / Cl mole ratio in the water-soluble zinc hydroxychloride soludons at a constant zinc level.

[0064] Example 2C, Example 4D, and Example 5E are compared in Table 5-3 below to understand if the use of different methods of making the water-soluble zinc hydroxychloride solutions having similar zinc and glycine strength achieve similar Zn / Cl mole ratios. The data indicates that the water-soluble zinc hydroxy chloride solutions produced by the different methods have similar properties.Table 5-3: Properties of the water-soluble zinc hydroxy chloride solutions of Examples 2C, 4D, and 5EExample 6 - Making water-soluble zinc hydroxychloride solutions using ZnO, HCl, and glycine at a 7% Zn concentration

[0065] The water-soluble zinc hydroxy chloride solutions of Examples 6A-6G were prepared according to the general method previously described in Example 5. Examples 6 A through 6G differ in the material quantities used in the general method. The material quantities are given in Table 6-1 and the properties of the water- soluble zinc hydroxychloride solutions of Examples 6A to 6G are given in Table 6-2.GULBRA 3.4-013Table 6-1: Material Quantities used to prepare Examples 6A-6GTable 6-2: Properties of ZnHC liquid composition prepared as above:

[0066] The 7% zinc water-soluble zinc hydroxy chloride solutions demonstrate similar properties as the water-soluble zinc hydroxychloride solutions at 5% zinc. Specifically, increasing the glycine concentration in the Zn-glycine system resulted in greater H+ion generation. As a result, a lower amount of HC1 was required to adjust the solution to a high pH.Example 7 - Making a water-soluble zinc hydroxy chloride solution using potassium hydroxide (KOH) and betaineGULBRA 3.4-013

[0067] In Example 7A, betaine was used to replace glycine to make water-soluble zinc hydroxychloride solutions. Below is a description of the process. Table 7 includes the material quantities for Example 7A.

[0068] A 20% zinc chloride soludon was charged into a clean glass round bottom flask. Water was added to achieve the desired concentration. The resulting solution was stirred at a constant agitation speed of 300 RPM using a mechanical stirrer to ensure uniform mixing. Subsequently, 1 g betaine was added gradually to the solution under continuous stirring. Upon betaine addition, a white precipitate was observed, indicating the onset of a reaction between zinc ions and betaine. Simultaneously, the pH of the solution was increased, reaching a value of around 6.0. Afterward, a 10% KOH solution was slowly introduced into the reaction mixture. As the KOH solution was added, the solution began to turn milky, indicating instability of the mixture. Approximately 19 g of 10% KOH solution was added to the solution. At this point, the addition of KOH was immediately stopped.Table 7: Material Quantities used to prepare Example 7A

[0069] After adding only 1 g of betaine to the ZnCL solution, the clear ZnCL solution became a white slurry and the pH of the slurry increased to about 6, which was different from that of glycine where the solution was clear and the pH of the solution dropped to about 3.5. To check the behavior further, KOH was added, which increased the pH of the mixture to 6.23. As the pH increased, the precipitate became milky white and thicker. This indicated that zinc hydroxide was likely formed. In the other set of experiments, more betaine was added and the same effect was observed. The use of betaine as a buffer does not form water-soluble zinc hydroxychloride solutions. In contrast, glycine contributes significantly to the solubility and clarity of the final water-soluble zinc hydroxychloride solutions. The presence of glycine helps to dissolve intermediate precipitates and promotes the formation of a transparent water-soluble zinc hydroxychloride solution. Compared to glycine, betaine does not have -NH2 group which contributes to the production of water-soluble zinc hydroxychloride solutions. This indicates that glycine plays an effective stabilizing role in the system, unlike betaine, making it the preferred amino acid for achieving clear, shelf-stable water-soluble zinc hydroxychloride formulations.Example 8 - Making a water-soluble zinc hydroxychloride solution using potassium hydroxide (KOH) and L-arginine

[0070] A 20% ZnCL solution was charged into a glass round bottom flask. Water was added. The solution was agitated at 300 RPM agitation speed. 2 grams of L- Arginine was charged into the glass flask. After adding L- Arginine to the ZnCL solution, the pH of the mixture was about 5.8, which was higher than that of a comparable process using glycine. Also, a white cloudy solution or white precipitate was formed after the addition of L-arginine. A 10% KOH solution was added and the pH of the solution increased to 6.23. As theGULBRA 3.4-013solution pH was increased, the precipitate became milky white. The material quanlilics used to prepare Example 8A are included in Table 8Table 8: Material Quantities used to prepare Examples 8A

[0071] It is speculated that zinc hydroxide was formed, as zinc ions tend to precipitate out as hydroxide. Without intending to be bound by theory, water-soluble zinc hydroxychloride solutions cannot be prepared by using L-arginine as a buffer. Even though L-arginine has the -NH2 group, the guanidino group of the L-Arginine may prevent the formation of water-soluble zinc hydroxychloride solulions from ZnCE and KOH.Example 9 - Making water-soluble zinc hydroxychloride solutions using glycine and L-arginine

[0072] The water-soluble zinc hydroxychloride solutions of Examples 9A to 9E were produced by the following general method. Examples 9A through 9E differ in the material quantities used in the general method. The material quantities are given in Table 9-1 and the properties of the water-soluble zinc hydroxychloride solutions of Examples 9A to 9E are given in Table 9-2.

[0073] A 20% ZnCb solution was charged into a glass round bottom flask. Water was added, and the solution was agitated at 300 RPM agitation speed. L- Arginine was charged into the glass flask. White precipitates were formed and the pH of the solution increased to about 5.5. Subsequently, about 80% of the total amount of glycine was charged to the flask under agitation, and the mixture became clear. The pH of the solution dropped to 4.5. A 10% KOH solution was added to the solulion over a period of 30 minutes at room temperature unlil the solulion became hazy. At that stage, KOH addition was stopped. Subsequently, the remaining 20% of the total quantity of glycine was added to the flask, and the solution became clear. The pH was measured at this stage. After glycine charging, the batch was agitated for about 15 minutes. The batch was filtered and analyzed.Table 9-1: Material Quantities used to prepare Examples 9A-9EGULBRA 3.4-013Table 9-2: Properties of the water-soluble zinc hydroxychloride solutions of Examples 9A-9E*: Theoretical values.

[0074] As shown in Example 9, L- Arginine may act as a mild base and may increase the solution pH, leading to the temporary formation of a white precipitate. Glycine plays a role in re-dissolving the precipitate and stabilizing the solulion. Glycine enables the controlled addition of KOH without destabilizing the system. Increasing the glycine to L-arginine ratio generally improved the final pH and Zn / Cl mole ratio.Example 10- Making water-soluble zinc hydroxychloride solutions using glycine and L-arginine

[0075] The water-soluble zinc hydroxy chloride solutions of Examples 10A to 10E were produced by the following general method. Examples 10A through 10E differ in the material quantities used in the general method. The material quantities are given in Table 10-1 and the properties of the water-soluble zinc hydroxychloride solutions of Examples 10A to 10E are given in Table 10-2.

[0076] A 20% ZnCO soludon was charged into a glass round bottom flask. Water was added and the solution was agitated at a 300 RPM agitation speed. 80% of the total quantity of glycine was added to the solution. The pH of the solution dropped to about 3.5. To this acidic solution, a 10% KOH solution was added over a period of 30 minutes at room temperature until the solution became hazy. At this stage, further KOH addition wasGULBRA 3.4-013stopped. Subsequently, the remaining 20% of the total quantity of glycine was added to the flask, and the solution became clear. The pH was measured at this stage. After the glycine was added, the batch was agitated for about 15 minutes. L-arginine was added to the solution and the solulion was agitated for 30 minutes. Then, the batch was taken for analysis.Table 10-1: Material Quantities used to prepare Examples 10A-10ETable 10-2: Properties of the water-soluble zinc hydroxychloride solutions of Examples 10A-10E*: Theoretical value

[0077] Adding L-Arginine at the end of the reaction does not produce any precipitates in the presence of glycine. The presence of the glycine stabilizes the water-soluble zinc hydroxychloride soludon against the basicity of the L- Arginine. Thus a stable water-soluble zinc hydroxychloride solution may be formed.Example 11 - Making water-soluble zinc hydroxychloride solutions using ammonia

[0078] In Example 11, the following zinc chloride and NH4OH aqueous solutions were prepared.

[0079] ZnCH solution: 42 parts of ZnCE (assay: 99%) was dissolved in 58 parts of water to make 20% w / w ZnCH aqueous solution.GULBRA 3.4-013

[0080] NH4OH solution: 78 parts of NH4OH solution (assay: 25-28%) is dissolved in 22 parts water to make 20.5% w / w NH4OH solution (Ammonia Solution).

[0081] The water-soluble zinc hydroxychloride solutions of Examples 11A to HE were produced by the following general method. Examples HA through HE differ in the material quanlilics used in the general method. The material quantities are given in Table 11-1 and the properties of the water-soluble zinc hydroxychloride solutions of Examples 11 A to 1 IE are given in Table 11-2.

[0082] A 20% ZnCE solution was charged into a glass flask, followed by water. The solution was agitated at a 300 RPM agitation speed. 80% of the total quantity of glycine was added to the glass flask. The pH of the solution dropped to about 3.5. To this acidic solution, 20.5% w / w NH4OH was added over a period of 30 minutes at room temperature. The NH4OH solution was added until the solulion became hazy. At this stage, the addition of NH4OH was stopped. The pH was measured at this stage. The remaining 20% of the total amount of glycine was added, and the batch was agitated for about 15 minutes to obtain a clear water-soluble zinc hydroxychloride solution.Table 11-1: Material Quantities used to prepare Examples 11A-11EGULBRA 3.4-013Table 11-2: Properties of the water-soluble zinc hydroxychloride solutions ofExamplesllA-llE*: Theoretical value.

[0083] The zinc chloride reacted with the ammonia solulion differently than the caustic solution. Normally, white precipitates are expected to form at a pH of about 6, but in this case, no precipitation was observed even at a pH close to 7. Also, the water-soluble zinc hydroxychloride solution was formed with a much higher Zn / Cl mole ratio.Example 12 - Making water-soluble zinc hydroxychloride solutions using ammonia without glycine

[0084] The water-soluble zinc hydroxy chloride solutions of Examples 12A to 12B were produced by the following general method. Examples 12A and 12B differ in the material quantities used in the general method. The material quantities are given in Table 12-1 and the properries of the water-soluble zinc hydroxy chloride solutions of Examples 12A and 12B are given in Table 12-2.

[0085] A 20% ZnCH solution was charged into a glass flask and water was added. The solution was agitated at a 300 RPM agitation speed. To this solution, a 20% NH4OH solution was added over a period of 30 minutes at room temperature. The NH4OH aqueous solution was added until the reaction mass became hazy. At a pH of about 6.6, the solution was hazy, so further addition of NH4OH was stopped. The hazy solution was mixed for 15 minutes. The mixture was slightly hazy, and the mixture was filtered to give a clear solution.GULBRA 3.4-013Table 12-1: Material Quantities used to prepare Examples 12A and 12BTable 12-2: Properties of the water-soluble zinc hydroxychloride solutions of Examples 12A and 12B*: Theoretical value.

[0086] For the water-soluble zinc hydroxychloride solutions prepared with NH4OH and without glycine, the pH reached a maximum of about 6.6. Above a pH of about 6.6, haze began to develop. When the NH4OH solution was continuously added, the water-soluble zinc hydroxychloride solution became increasingly hazy, and a precipitate started to form. Additionally, the characlcrislic smell of ammonia was also developed. Example 13 - Making water-soluble zinc hydroxychloride solutions using urea

[0087] Zinc chloride and KOH aqueous solutions were prepared as described below. Urea was used to reduce the irritancy of the soludon.

[0088] ZnCF aqueous solution: 42 parts of ZnCh (assay: 99%) were dissolved in 58 parts of water to obtain a 20% w / w Zinc (Zn) aqueous solution.

[0089] KOH aqueous solution: 17 parts of KOH flakes (assay: 85%) were dissolved in 83 parts of water to obtain a 10% w / w Potassium (K) aqueous solution.

[0090] The water-soluble zinc hydroxychloride solutions of Examples 13A to 13G were produced by the following general method. Examples 13A through 13G differ in the material quantities used in the general method. The material quantities are given in Table 13-1 and the properties of the water-soluble zinc hydroxychloride solutions of Examples 13A to 13G are given in Table 13-2.

[0091] The ZnCF aqueous solution was added to a glass flask. Water was added to the flask. The solution was agitated at a rotation speed of 300 RPM. 80% of the total amount of glycine was added to the flask and the pH was reduced to about 3.6. The urea was added to the flask, and the pH increased to about 4.0. The KOH aqueous solution was added slowly over 30 minutes at a temperature of 25 °C to 35 °C until the solution turned hazy. After the solution turned hazy, the addition of KOH aqueous solution was stopped. The remaining 20%GULBRA 3.4-013of the total amount of glycine was added to the solution, which clarified the solution. The pH of the solution was measured. The solution was agitated for an additional 30 minutes.

[0092] In Examples 13D to 13G, no KOH was added and the ratio of glycine to urea was different. Urea did not significantly affect the pH of the solution. Glycine was used to obtain a clear solution and to lower the pH, which further facilitated KOH addition. The examples highlight the difference between the ZnCU + Urea solution and the ZnCE + Urea + Glycine solution.Table 13-1: Material Quantities used to prepare Examples 13A-13GGULBRA 3.4-013Table 13-2: Properties of the water-soluble zinc hydroxychloride solutions of Examples 13A-13G*: Theoretical value.Example 14 - Making water-soluble zinc hydroxychloride solutions using urea, potassium hydroxide and glycine

[0093] The water-soluble zinc hydroxychloride solutions of Examples 14A to 14C were produced by the following general method. Examples 14A through 14C differ in the material quanlilics used in the general method. The material quantities are given in Table 14-1 and the properties of the water-soluble zinc hydroxychloride solutions of Examples 14A to 14C are given in Table 14-2.GULBRA 3.4-013

[0094] Water was added to a round bottom flask. The water was stirred at an agitation speed of 300 rpm using an overhead stirrer, and the water was heated to a temperature of 65 °C to 75 °C. Glycine was added to the water. Urea was added to the solution. The solution was agitated for 10 to 15 minutes. The ZnO was slowly added to the solulion and the temperature was maintained at 65 °C to 75 °C. A white slurry was formed upon addition of the ZnO. HC1 was slowly added to the slurry until a clear solution formed. The solution was stirred for 10 to 15 minutes. The solulion was allowed to cool to room temperature. Some undissolved ZnO particles were present in the solution, and the solution was filtered. The filtered solulion was clear in appearance.

[0095] Example 14A was a zero (0%) glycine batch in which no glycine, only urea, was added to the batch. In Example 14A, urea was dispersed into the hot water. Then, ZnO was added slowly into the water in the glass round bottom flask. The temperature was increased to 65 °C to 75 °C. HC1 was added by an additional glass funnel unlil a clear solution was obtained. The concentration of chloride was increased which resulted in a decrease in the Zn / Cl mole ratio.Table 14-1: Material Quantities used to prepare Examples 14A-14CTable 14-2: Properties of the water-soluble zinc hydroxychloride solutions of Examples 14-14CExample 15 - Making water-soluble zinc hydroxychloride solutions using ethanolamine and glycineGULBRA 3.4-013

[0096] The water-soluble zinc hydroxy chloride solutions of Examples 15A to 15F were produced by the following general method. Examples 15A through 15F differ in the material quanlilics used in the general method. The material quantities are given in Table 15-1 and the properties of the water-soluble zinc hydroxychloride solutions of Examples 15A to 15F are given in Table 15-2.

[0097] A zinc chloride solution was added to a round bottom flask and was agitated at a speed of 300 rpm using an overhead stirrer. Water was added to the flask and the solution was agitated for 10 to 15 minutes.80% of a total amount of the glycine was added to the soludon, and the solution was agitated for 10 to 15 minutes. Ethanolamine was slowly added to the solution until a haze was observed. After the haze was observed, the addition of ethanolamine was stopped. The solution was agitated for 10 to 15 minutes. The remaining 20% of the total amount of glycine was added to the solution, and the solution was stirred for 10 to 15 minutes. The solution became clear after the addition of the glycine.

[0098] Example 15A was a zero glycine batch and the formation of a white precipitate was observed in Example 15 A.Table 15-1: Material Quantities used to prepare Examples 15A-15FTable 15-2: Properties of the water-soluble zinc hydroxychloride solutions of Examples 15A-15F*: Theoretical value.Example 16- Making water-soluble zinc hydroxychloride powder by spray drying

[0099] In continuation of the experimental work on water-soluble zinc hydroxychloride, a liquid composition was prepared in accordance with Example 5E. In the examples, the quantity of water was reduced by 30% in order to increase the zinc strength to 10%, compared to the 5% Zinc strength of Example 5E. The objectiveGULBRA 3.4-013was to achieve a zinc concentration of 10% in the liquid composition (referred to as the feedstock) to enhance the economic viability of the spray drying process, in comparison to processing a more diluted 5% Zn solulion (Example 5E).

[0100] The resulling water-soluble zinc hydroxychloride soludon was subsequently evaluated for spray drying to obtain water-soluble zinc hydroxychloride powder. Following is a brief process description for making the feedstock and spray drying operation conditions.

[0101] Water was added to a round bottom flask and was agitated at a speed of 300 rpm by an overhead stirrer. The water was heated to a temperature of 65 °C to 75 °C. 80% of the total amount of glycine was added to the water. The solution was agitated for 10 to 15 minutes. ZnO was slowly added to the solution while the temperature was maintained at 65 °C to 75 °C. A white slurry was formed upon the ZnO addition. HC1 was slowly added into the slurry until it became an almost clear solution. The solution was stirred for 10 to 15 minutes and the temperature was maintained at 65 °C to 75 °C. The remaining 20% of the total amount of glycine was added to the solution, and the solution was stirred for 10 to 15 minutes. The solution became clear. The solution was allowed to cool to room temperature. Some undissolved ZnO particles were observed in the solution and the particles were removed by filtration. The solution was spray dried to form a fluffy white powder.

[0102] The compositions and properties of Examples 16A and 16B are included in Tables 16-1,16-2, and 16-3 below.Table 16-1: Material Quantities used to prepare Examples 16A and 16BTable 16-2: Properties of the water-soluble zinc hydroxychloride solutions of Examples 16A and 16BGULBRA 3.4-013Table 16-3: Properties of the water-soluble zinc hydroxychloride powder of Examples 16A and 16BExample 17 - Making water-soluble zinc hydroxychloride powder by freeze drying

[0103] Freeze drying is a dehydration process that removes water from a frozen product via sublimation (transition from solid ice directly to vapor) under vacuum. This technique preserves chemical integrity, makes products shelf-stable, and prevents degradation from heat.

[0104] A water-soluble zinc hydroxychloride solution was prepared in accordance with Example IF. The resulting water-soluble zinc hydroxychloride soludon was freeze dried to make solid water-soluble zinc hydroxychloride powder.

[0105] The feedstock (prepared in accordance with Example IF) was frozen in the plate chillers for about 8 hours at a temperature of -25 °C. This frozen material was loaded into the drying chamber of the freeze dryer. Vacuum was applied and the pressure was reduced to below 0.6 mbar in the drying chamber. Subsequently, radiation heater plates were heated by flowing water at a temperature of 60 °C to 70 °C through the radiation heater plates. The water content of the frozen product was sublimated under negative pressure and vapor formed and collected on the cooling coils of the ice condenser. The temperature of the cooling coils was around -50 °C. The drying was continued until all the water from the frozen material was collected on cooling coils of the ice condenser. A shiny, crystalline white solid was obtained through freeze drying. The quality of the freeze-dried salt suggests that the matrix structure remained intact during the freeze-drying process. 100 g of feedstock generated 28g solid material.Table 17-1: Material Quantities used to prepare Examples 17Table 17-2: Properties of the water-soluble zinc hydroxychloride solution of Example 17LGULBRA 3.4-013Table 17-3: Properties of water-soluble zinc hydroxychloride powder of Example 17Example 18- Making a high concentration water-soluble zinc hydroxychloride solution from zinc chloride, potassium hydroxide, and glycine

[0106] Zinc chloride and potassium hydroxide aqueous solutions were prepared with the following concentrations. These solutions were used in Example 18.

[0107] ZnCl2aqueous solution: 67 parts of ZnCH (assay: 99%) were dissolved in 33 parts of water to obtain a 32% w / w zinc chloride aqueous solution.

[0108] KOH aqueous solution: 54 parts of KOH flakes (assay: 85%) were dissolved in 46 parts of water to obtain a 32% w / w potassium hydroxide aqueous solution.

[0109] The high concentration water-soluble zinc hydroxy chloride solutions of Examples 18A and 18B were produced by the following general method. Examples 18A and 18B differ in the material quantities used in the general method. The material quantities are given in Table 18-1 and the properties of the high concentration water-soluble zinc hydroxychloride solutions of Examples 18A and 18B are given in Table 18-2.

[0110] The 32% Zinc chloride solution was charged into a round bottom flask and was stirred at an agitation speed of 300 rpm. Water was added and the solution was agitated for 10-15 minutes. A slight exotherm was observed. 90% of the total quantity of glycine was charged to the flask, and the mixture was agitated for 10-15 minutes. The 32% p otassium hydroxide solution was slowly added over 1 hour 30 minutes until a haze was observed in the mixture. The addition of KOH solution was stopped and the reaction mixture was agitated for 10-15 minutes. The remaining 10% of the glycine was added into the solution, and the solution was agitated for 10-15 minutes until clear.Table 18-1: Material Quantities used to prepare Examples 18A and 18BGULBRA 3.4-013Table 18-2: Properties of the high concentration water-soluble zinc hydroxychloride solutions of Examples 18A and 18BExample 19 - Making water soluble z inc h ydroxychloride liquid compositions from ZnO, HCl, and glycine at different zinc concentrations

[0111] The water-soluble zinc hydroxy chlroide solutions of Examples 19 A to 19C were produced by the following general method. Examples 19A to 19C differ in the material quanlilics used in the general method. The material quantities are given in Table 19-1 and the properties of the water soluble zinc hydroxy chloride solutions of Examples 19A to 19C are given in Table 19-2.

[0112] Water was added to a round bottom flask and was agitated at a speed of 300 rpm and heated to a temperature of 90-95 °C. Glycine was added to the heated water and the soludon was agitated for 10 to 15 minutes. ZnO was added to the solution while the solution was maintained at a temperature of about 96 °C. A white slurry was formed. HCl was added to the slurry until the slurry became clear while the temperature was maintained at about 97 °C. The resulting solution was stirred for 4 hours and a clear solution was obtained. The solution was cooled to room temperature. Some undissolved ZnO particles were observed and were isolated from the solution by filtration. The final solution was clear.Table 19-1: Material Quantities used to prepare Examples 19A to 19CGULBRA 3.4-013Table 19-2: Properties of the water-soluble zinc hydroxychloride solutions of Examples 19A to 19CExample 20 - Antiperspirant Performance Study

[0113] A 24-hour antiperspirant efficacy study was conducted using a backscreen method on 21 female subjects with healthy skin. The study measured the relative reduction of sweating compared to untreated control areas, under dermatological supervision. Product assignment followed a randomization scheme. Test products (75 pl) were applied by a technician to 16 marked areas (4 cm x 5 cm) on the subjects’ backs. These areas were then covered with an occlusive patch test system for two hours. This application was repeated for four consecutive days.

[0114] Twenty-four hours after the final product application, pre-weighed absorbent pads were affixed to the test areas. Subjects then entered an 80 °C sauna for approximately 15 minutes to induce sweating. The amount of sweat was determined gravimetrically. Each test product’s efficacy was compared to a corresponding untreated area on the contralateral side of the subject’s back. Statistical analysis includes comparisons to untreated areas and between different treatments.

[0115] For comparative analysis, two contralateral test fields (right and left of the spine) were considered a pair. The contralateral test fields were used to compare a test product with an untreated control area. The treated and untreated sides of the back alternate between subjects, and test areas were assigned by cyclic permutation.

[0116] A day-by-day description of the procedure is included below:

[0117] Day 1: Subjects arrive, are informed about the study, and provide written consent. Test products are applied to the designated areas. Subjects rest for about 5 minutes for product absorption. All test areas are then covered with the patch test system, which is removed approximately 2 hours (± 5 minutes) later by a technician.

[0118] Day 2 to Day 4 : Subjects return, and the product application is repeated as described for Day 1.

[0119] Day 5 (24 hours after last product application): Subjects arrive, and their backs are cleaned with water and dried. Both treated and untreated contralateral areas are covered with absorbent pads secured by the patch test system. Subjects then he prone in an 80°C sauna for about 15 minutes.GULBRA 3.4-013

[0120] Investigational Method: Absorbent pads are pre-weighed in cups under standard room conditions. After application and the sauna session, the pads are immediately removed with tweezers, placed back into their cups, and re- weighed under standard room conditions. The difference in gravimetric measurements represents the absorbed sweat weight, with one measurement per test area per assessment time using an analytical scale.

[0121] The results of the antiperspirant performance study are included in Table 20-1 and the properties of the tested water-soluble zinc hydroxychloride compositions are included in Table 20-2.Table 20-1: Results of the Backscreen Test<*: Sweat Reduction.Table 20-2: Properties of the water-soluble zinc hydroxychloride samples

[0122] After 24 hours of the last product’s application with 20% aluminum chlorohydrate (ACH) (at anhydrous solid level), an average decrease in sweat weight of 51% was found in comparison to the untreated area. This decrease was stati stical I y significant with a p- value of <0.001.

[0123] After 24 hours of the last product’s application, a water-soluble zinc hydroxy chloride sample at 3% Zn with a Glycine / Zn mole ratio of 2.3 and a Zn / Cl mole ratio of 1.04 demonstrated an average sweat reduction of 59% in comparison to an untreated area. This decrease was statistically significant with a p-value of <0.001. However, in comparison to reference product 20% ACH, this decrease was statistically non-significant with a p-value of 0.07.

[0124] After 24 hours of the last product’s application, the water-soluble zinc hydroxychloride of Example 2C-1 showed an average sweat reduction of 74% in comparison to an untreated area. This decrease was statistically significant with a p-value of <0.001. Additionally, in comparison to reference product 20% ACH, this decrease was statistically significant with a p-value of < 0.001.GULBRA 3.4-013

[0125] After 24 hours of the last product’s application, the water-soluble zinc hydroxychloride of Example 2D-1 showed an average sweat reduction of 69% in comparison to the untreated area. This decrease was slalislically significant with a p-value of <0.001. Additionally, in comparison to reference product 20% ACH, this decrease was statistically significant with a p-value of about 0.003.

[0126] In conclusion, the water-soluble zinc hydroxychloride samples demonstrate sweat reduction properties similar to or better than the ACH solution.Example 21: Microbial Challenge Study

[0127] Total bacterial count was tested for the water-soluble zinc hydroxychloride sample of Example 2D and was found to be less than 10 cfu / ml. The total fungal count was tested for Example 2D and was found to be less than 10 cfu / ml. A microbial challenge test was also performed on the water-soluble zinc hydroxychloride sample of Example 2D and showed no growth for different microbial organisms including E.coli, staphylococcus aureus, pseudomonas aeruginosa, Candida albicans, and aspergillus brasiliensis. No growth was observed at 14 and 28 days for bacteria and fungi. The results are included in Table 21 below.Table 21: The Results of Microbial Challenge Study<<Example 22: Deodorant Study

[0128] A deodorant study evaluated the efficacy of a deodorant product comprising the water-soluble zinc hydroxychloride of Example 2D-2 against axillary odor compared to a reference product. In this study the reference product was a 3% glycerine aqueous solution. The study started with a 10-day wash-out period where subjects used only perfume-free soap and avoided deodorants / antiper spirants. On Day 1, the subjects underwent a supervised standardized axillary wash. On Day 2, 24 hours after washing, four trained “odor judges” conducted a baseline sweat odor assessment using a six-point scale where 0 = no odor, and 5 = very strong odor. After the baseline assessment, the subjects performed another standardized wash, and the test products were applied to their axillae (300 pl per axilla) by a trained technician. The product was spread with a finger-cot and dried with a hair dryer. Loose- li III ng clothing was then carefully put on to avoid contact with the axillae.GULBRA 3.4-013

[0129] Subsequent odor assessments were repeated by the odor judges 24, 48, and 72 hours after product application on Days 3, 4, and 5, respectively. Scores were entered into a computer system. The odor judges were regularly tested for their smelling ability before and during the study. The results of the deodorant test are included in Table 22-1 and the properties of the water-soluble zinc hydroxy chloride of Example 2D-2 are included in Table 22-2.Table 22-1: Mean Malodor Scoring of all 4 Included Odor Judges0 = no perceptible sweat odor;1 = slight perceptible sweat odor;2 = definite perceptible sweat odor;3 = moderate perceptible sweat odor;4 = strong perceptible sweat odor;5 = very strong perceptible sweat odor.Table 22-2: Deodorant Test Results< <1: 3% glycerine aqueous solution.2: Similar to Example 2D except more water and glycerine are added to achieve 3% Zn and 3% glycerine.Table 22-3: Properties of the water-soluble zinc hydroxychloride solutions of Example 2D-2

[0130] As determined in this study, significantly lower sweat odor values were observed for the axilla treated with the test product of water-soluble zinc hydroxychloride of Example 2D-2 compared to the referenceGULBRA 3.4-013product of 3% glycerine aqueous solution for 24 hours, 48 hours and 72 hours after product application. Significantly less sweat odor was found for the test product in comparison to the reference product of 3% glycerine aqueous solution for 24 hours, 48 hours and 72 hours after application.

[0131] Aspect 1. A personal care composition comprising a water-soluble zinc hydroxychloride having a chemical formula Zn(OH)2-xClx, wherein x is from 0.67 to 1.89.

[0132] Aspect 2. The personal care composition of aspect 1, wherein x is from 0.83 to 1.25.

[0133] Aspect 3 is the personal care composition of aspect 1 or 2, further comprising glycine.

[0134] Aspect 4. The personal care composition of aspect 3, wherein a molar ratio of glycine to zinc is from 0.5 to 2.5.

[0135] Aspect 5. The personal care composition of aspect 3 or 4, wherein a molar ratio of zinc to chlorine is from 0.53 to 1.5.

[0136] Aspect 6. The personal care composilion of any one of aspects 1 to 5, further comprising glycine and one or more of alanine, arginine, asparagine, cysteine, glutamine, histidine, leucine, lysine, methionine, phenylalanine, proline, serine, tryptophan, tyrosine, and or valine.

[0137] Aspect 7. The personal care composition of any one of aspects 1 to 6, wherein a total amount of zinc is from 0.5% to 40% by weight, based on a total weight of the personal care composition.

[0138] Aspect 8. The personal care composition of any one of aspects 1 to 6, wherein a total amount of zinc is from 0.5% to 15% by weight, based on a total weight of the personal care composition.

[0139] Aspect 9, The personal care composition of any one of aspects 1 to 6, wherein a total amount of zinc is from 20% to 35% by weight, based on a total weight of the personal care composilion.

[0140] Aspect 10. The personal care composilion of any one of aspects 1 to 9, wherein the personal care composition is a skin care product.

[0141] Aspect 11. The personal care composition of any one of aspects 1 to 10, wherein the personal care composition is an antiperspirant or a deodorant.

[0142] Aspect 12. The personal care composition of any one of aspects 1 to 10, wherein the personal care composition is a whole-body deodorant.

[0143] Aspect 13. The personal care composition of any one of aspects 1 to 9, wherein the personal care composition is a shampoo, a hair conditioner, a body wash, a shower gel, or a bar soap.

[0144] Aspect 14. The personal care composition of any one of aspects 1 to 9, wherein the personal care composition is an oral care product.

[0145] Aspect 15. The personal care composilion of any one of aspects 1 to 9, wherein the personal care composition is an aerosol, a gel, a cream, a spray, a slick, or a roll-on formulation.

[0146] Aspect 16. A method of making a water-soluble zinc hydroxychloride, the method comprising: reacting zinc chloride with a base to form a reaction product comprising the water-soluble zinc hydroxychloride, wherein the water-soluble zinc hydroxychloride has a chemical formula Zn(OH)2-xClx, wherein x is from 0.67 to 1.89.

[0147] Aspect 17. The method of aspect 16, further comprising adding glycine to the reaction product.GULBRA 3.4-013

[0148] Aspect 18. The method of aspect 16 or 17, wherein the base comprises one or more of sodium hydroxide, potassium hydroxide, calcium hydroxide, calcium oxide, calcium carbonate, magnesium hydroxide, magnesium oxide, zinc hydroxide, zinc oxide, ammonium hydroxide, urea, an amine derivative, or ethanol amine.

[0149] Aspect 19. A method of making a water-soluble zinc hydroxychloride, the method comprising: reacting zinc oxide or a water-insoluble zinc hydroxide with an acid to form a reaction product comprising the water-soluble zinc hydroxychloride, wherein the water-soluble zinc hydroxychloride has a chemical formula Zn(OH)2-xClx, wherein x is from 0.67 to 1.89.

[0150] Aspect 20. The method of aspect 19, further comprising adding glycine to the reaction product.

[0151] Aspect 21. The method of aspect 19 or 20, wherein the acid comprises one or more of hydrochloric acid, nitric acid, or sulfuric acid.

[0152] Technical features of the present disclosure have been described with reference to particular aspects. However, these aspects are merely illustrative of the technical features of the present disclosure. It should be understood that modifications may be made to the illuslrali ve aspects and that other arrangements may be devised without departing from the spirit and scope of the present disclosure. Accordingly, the scope of the present disclosure is not limited to the particular aspects described herein but is defined by the appended claims.

Claims

1. GULBRA 3.4-013CLAIMS1. A personal care composition comprising a water-soluble zinc hydroxychloride having a chemical formula Zn(OH)2-xClx, wherein x is from 0.67 to 1.89.

2. The personal care composition of claim 1 , further comprising glycine.

3. The personal care composition of claim 2, wherein a molar ratio of glycine to zinc is from 0.5 to 2.5.

4. The personal care composition of claim 2 or 3, wherein a molar ratio of zinc to chlorine is from 0.53 to 1.5.

5. The personal care composition of any one of claims 1 to 4, further comprising glycine and one or more of alanine, arginine, asparagine, cysteine, glutamine, histidine, leucine, lysine, methionine, phenylalanine, proline, serine, tryptophan, tyrosine, and or valine.

6. The personal care composition of any one of claims 1 to 5, wherein a total amount of zinc is from 0.5% to 40% by weight, based on a total weight of the personal care composition.

7. The personal care composilion of any one of claims 1 to 5, wherein a total amount of zinc is from 0.5% to 15% by weight, based on a total weight of the personal care composition.

8. The personal care composition of any one of claims 1 to 5, wherein a total amount of zinc is from 20% to 35% by weight, based on a total weight of the personal care composilion.

9. The personal care composition of any one of claims 1 to 8, wherein the personal care composition is an antiperspirant or a deodorant.

10. The personal care composition of any one of claims 1 to 9, wherein the personal care composition is an aerosol, a gel, a cream, a spray, a slick, or a roll-on formulation.

11. A method of making a water-soluble zinc hydroxy chloride, the method comprising:reacting zinc chloride with a base to form a reaction product comprising the water-soluble zinc hydroxychloride,wherein the water-soluble zinc hydroxychloride has a chemical formula Zn(OH)2-xClx, wherein x is from 0.67 to 1.89.

12. The method of claim 11, further comprising adding glycine to the reaction product.GULBRA 3.4-01313. The method of claim 11 or 12, wherein the base comprises one or more of sodium hydroxide, potassium hydroxide, calcium hydroxide, calcium oxide, calcium carbonate, magnesium hydroxide, magnesium oxide, zinc hydroxide, zinc oxide, ammonium hydroxide, urea, an amine derivative, or ethanol amine.

14. A method of making a water-soluble zinc hydroxychloride, the method comprising:reacting zinc oxide or a water-insoluble zinc hydroxide with an acid to form a reaction product comprising the water-soluble zinc hydroxychloride,wherein the water-soluble zinc hydroxychloride has a chemical formula Zn(0H)2-xClx, wherein x is from 0.67 to 1.89.

15. The method of claim 14, further comprising adding glycine to the reaction product.

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