MXPA97003189A - Method for manufacturing solutions of polyhydrical alcohols with antitranspirant active compounds with better efficiency - Google Patents

Abstract

The present invention relates to a process for preparing a solution of an aluminum antiperspirant salt of improved efficiency in a polyhydric alcohol by (a) providing an aqueous solution consisting essentially of from about 5% to about 19% by weight of an antiperspirant salt of aluminum of improved efficiency in water, the antiperspirant salt of aluminum that has been prepared in situ without drying to a solid powder, (b) mixing the aqueous solution with a sufficient quantity of a liquid polyhydric alcohol, to provide a solution mixture having a ratio of antiperspirant salt to polyhydric alcohol of from about 1: 4 to about 1.2: 1, and (c) rapidly evaporating the water from the mixed solution under vacuum to provide a final liquid solution of polyhydric alcohol containing about 20 to 50% aluminum antiperspirant salt of improved efficiency and approximately 2 to 16% water, with The rest is polyhydric alcohol. A glycinate, alkaline salt, such as sodium, potassium or zinc glycinate can be added to the polyhydric alcohol before the addition of the antiperspirant salt solution in order to increase the pH of the recovered product to about 4.1 to 5.

Description

METHOD FOR MANUFACTURING SOLUTIONS OF POLYBURR ALCOHOLS WITH ANTITRANSPIRANT COMPOUNDS WITH IMPROVED EFFICACY This invention relates to solutions of active products to aluminum titranspirants, of improved efficacy in polyhydric alcohols. Aluminum and aluminum-zirconium antiperspirant salts of improved efficiency are well known and are described, for example, in GB 2,048,229, EP 405,598, US 4,359,456, US 4,775,528, US 4,859,446, US 4,871,525, US 4,900,534, US 4,944,933, US 5,202,115, US 5,234,677, US 5,296,623, and US 5,330,751. These improved salts are also known to rapidly return to their unimproved state (e.g., as evidenced by an area ratio of peak 4 to peak 3 of 0.3 or less in HPLC) in solution, particularly at concentrations greater than 20% . Consequently, antiperspirant salts improvements are generally only available in powder form. A number of references disclose various ways of making alcohol-soluble antiperspirant active products. These references include, for example, US 3,045, 153, US 3,420,932, US 3,523,130, and US 3,947,556. In each case REF: 24686 concentrated solutions of the antiperspirant active product (ie, in the range of 40 to 50%) are used as a starting material and the product is obtained as a powder, which must then be redissolved in the alcohol solution desired. These techniques antedate the availability of the improved efficiency salts and are not believed to be applicable to them since they would likely cause reversion to the unimproved state. EP 7191 exemplifies a process for manufacturing a powdered, spray-dried complex of aluminum chlorohydrate and propylene glycol, which complex is then dissolved in alcohol. Two methods for making polyhydric alcohol solutions of antiperspirant salts are described in EP 295,070 and EP 404,533. In these methods a powder antiperspirant salt, which may be a salt of improved efficiency, is dissolved in a polyhydric alcohol, such as propylene glycol. In the above case, the polyhydric alcohol contains approximately 10 to 20% water. In the latter case, the antiperspirant salt has a water content greater than 10%. A method for making polyhydric alcohol solutions of antiperspirant salts that are free of unbound water is described in US 4,781,917. In that method, a powdered antiperspirant salt, which may be a salt of improved efficiency (a 50% solution is exemplified), is dissolved in water, a polyhydric alcohol, such as propylene glycol, is added to the aqueous solution, then all the Water is removed by heating under vacuum. In EP 599,775, Example 21 describes a method for making a propylene glycol solution of an aluminum-zirconium antiperspirant salt neutralized with zinc glycinate. An aqueous solution of aluminum chlorohydrate is heated by reflux in the presence of a small amount of propylene glycol, the solution is cooled to 70 ° C, zirconyl hydroxychloride-gly is added, the solution is cooled to 40 ° C, then glycinate is added. of zinc followed by propylene glycol. Then, this solution is distilled under vacuum to remove the water, leaving a solution at 30% by weight of antiperspirant active product in propylene glycol. The methods described above suffer from a number of deficiencies. First, many of them are not efficient because they use a powder material. The isolation of a powder antiperspirant salt from the solution is time consuming and expensive. Second, it is believed that these methods will likely result in some loss of efficiency and / or will not provide clear solutions. The antiperspirant salts that have been obtained by spray drying are notoriously difficult to redissolve as clear solutions. In addition, any method that requires an aqueous salt concentration above 20% will likely suffer from some loss in efficiency or effectiveness. An object of the present invention is to provide an efficient method for the direct preparation of polyhydric alcohol solutions of antiperspirant salts of improved efficiency or efficacy without the need to first isolate the salt as a powder and without any significant loss in efficiency. Then, these solutions can be used directly in the preparation of antiperspirant compositions. The present invention comprises a process for preparing a solution of an aluminum antiperspirant salt, of improved efficiency in a polyhydric alcohol by: (a) providing an aqueous solution consisting essentially of from about 5% to about 20% by weight of an antiperspirant salt improved efficiency aluminum, in water, the improved efficiency aluminum antiperspirant salt that has been prepared on site without having dried to a solid powder; (b) mixing the aqueous solution with a sufficient amount of a liquid polyhydric alcohol to provide a mixed solution having an antiperspirant salt at the polyhydric alcohol ratio of from about 1: 4 to about 1.2: 1; and (c) rapidly evaporating the water from the mixed solution under vacuum to provide a liquid solution of polyhydric alcohol containing about 20 to 50% aluminum antiperspirant salt of improved efficiency and about 2 to 16% water, with the rest that is polyhydric alcohol. An alkaline glycinate salt, such as sodium or zinc glycinate, polyhydric alcohol can be added before the addition of the antiperspirant salt solution in order to increase the pH of the improved product to about 4.1 to 5.0. The first step in the process of the present invention, that is, step (a), requires the preparation of an aqueous solution consisting essentially of about 5% to about 20%, preferably about 8% to about 15%, by weight of an antiperspirant salt of aluminum of improved efficiency in water, the antiperspirant salt of aluminum of improved efficiency which has been prepared in situ without it having been dried to a solid powder. Any of the known methods for preparing aqueous solutions of antiperspirant salts of improved efficiency can be used. These methods include those described, for example, in GB 2,048,229, EP 405,598, US 4,359,456, US 4,775,528, US 4,859,446, US 4,871,525, US 4,900,534, US 4,944,933, US 5,202,115, US 5,234,677, US 5,296,623, and US 5,330, 751. Considering the method of preparation used, it is critical that the salts of improved efficiency, when reconstituted as 10% aqueous solutions, produce a chromatogram on HPLC (as described, for example, in US 5,330,751, which is incorporated herein by reference) wherein at least 70%, preferably at least 80%, of the aluminum is contained in two successive peaks, peaks 3 and 4 suitably labeled, wherein the ratio of the area under peak 4 to the area under peak 3 is at least 0.5, preferably at least 0.7, and in the preferred form at least 0.9 or higher. The term "improved efficiency antiperspirant aluminum salt" is intended to mean a salt that produces this HPLC chromatogram. The preferred improved antiperspirant salts are any of the conventional aluminum salts and the known aluminum-zirconium salts which are useful in antiperspirant compositions. These salts include aluminum hydroxyhalides or example, aluminum chlorohydrate), and mixtures or complexes thereof with zirconyl oxyhalides or zirconyl hydroxyhalides (eg, aluminum-zirconium hydrochloride). Preferred aluminum salts are those having the general formula Al2 (OH) 6-aXa / n where X is Cl, Br, I or N03, is already about 0.3 to about 4, preferably about 1 to 2, such that the molar ratio of Al to X is approximately 1: 1 to 2.1: 1. These salts generally have some water of hydration associated with them, typically in the order of 1 to 6 moles per mole of salt. More preferably, the aluminum salt is aluminum chlorohydrate (ie, X is Cl) and a is about 1, such that the molar ratio of aluminum to chlorine is about 1.9: 1 to 2.1: 1.

Preferred alurainium-zirconium salts are mixtures or compounds of the aluminum salts described above with zirconium salts of the formula ZrO (OH) 2-pbYb wherein Y is Cl, Br, I N03, or S04, b is about 0.8 a 2, and p is the valence of Y. The zirconium salts also have in general some water of hydration associated with them, typically in the order of 1 to 7 moles per mole of salt. Preferably, the zirconium salt is zirconyl hydroxychloride of the formula ZrO (OH) 2-bClb wherein b is about 1 to 2, preferably 1.2 to about 1.9. Preferred aluminum-zirconium salts have an Al: Zr ratio of from about 1.7 to about 12.5. More preferably about 2 to about 8, and a metal: X + Y ratio of about 0.73 to about 2.1, preferably about 0.9 to 1.5. a preferred salt is aluminum-zirconium hydrochloride (ie, X and Y are Cl), which has an Al: Zr ratio of from about 2 to about 8 and a metal: C1 ratio of about 0.9 to 2.1. Also, these complexes may contain a neutral amino acid, preferably glycine, typically with a ZrrGly ratio of about 1: 1 to 1: 4.

A preferred method for preparing aqueous solutions of antiperspirant salts of improved efficiency comprises heating a 5 to 18% solution of aluminum salt, preferably aluminum chlorohydrate, at a sufficient temperature and for a sufficient time to provide a peak area ratio of 4. to peak 3 in HPLC of at least 0.5, preferably at least 0.7, and most preferably at least 0.9, with at least 70% of the aluminum contained in the peaks. The aqueous solution can be obtained by diluting a commercially available, normal 50% salt solution with water to the desired concentration, which is preferably from 8 to 15%. The temperature and the heating time can be adjusted as necessary to achieve the desired degree of conversion to the improved state. In general, longer times are required at lower temperatures. It is preferred to heat above 50 ° C, preferably at 70 ° C to 100 ° C, for at least two hours, preferably for at least 10 hours or more. Excellent results are obtained by heating at about 80 ° to 85 ° C for about 15 to 20 hours. An alternative method for preparing aqueous solutions of aluminum hydroxyhalides of improved efficiency is that described in US 4,859,446 and US 5,356,609, the disclosures of which are incorporated herein by reference. In this method, aluminum metal is reacted with aluminum halide, typically aluminum chloride, or with hydrogen halide, typically hydrochloric acid, in water at a temperature of about 50 ° to 100 ° C, the concentration of the reactants that is such as to provide an aqueous solution of aluminum hydroxyhalide, typically aluminum chlorohydrate, of about 8 to 25%, preferably about 10 to about 20% by weight. If the antiperspirant salt used in step (a) is an aluminum-zirconium salt, it is preferred to prepare this salt by following one of the methods described above to make the aqueous solution of the improved aluminum salt, then further the zirconium salt , preferably zirconyl hydroxychloride, usually in the form of an aqueous solution, to the improved aluminum salt solution in an amount to provide an Al: Zr ratio of from about 1.7 to about 12.5, preferably about 2 to about 8. Naturally, the amount of each salt must be adjusted so that the final solution will have a total salt concentration within the specified limits as desired for step (a). It is also possible to add the zirconium salt to the aluminum salt solution before the heating step described above which converts the aluminum to the improved state. The liquid polyhydric alcohol which is used in step (b) may be selected from any of those which are generally used in cosmetic compositions and which are liquid at room temperature. These typically include liquid aliphatic alcohols having from 2 to 12 carbon atoms and two or more hydroxyl groups and polyaliphatic ether-polyhydroxy compounds, liquids. These include, for example, propylene glycol (either 1,2- or 1,3-), butylene glycol, diethylene glycol, dipropylene glycol, glycerin, sorbitol, trimethylolpropane, 2-methyl-2, pentane-diol, 2-ethyl-1, 3-hexanediol, propylene glycols, polypropylene glycols and mixtures thereof. Preferred polyhydric alcohols are propylene glycol, butylene glycol, diethylene glycol, dipropylene glycol, glycerin, sorbitol and mixtures thereof. Most preferred are propylene glycol and sorbitol.

The liquid polyhydric alcohol can be mixed with the antiperspirant salt solution, at any temperature between about 0 ° C and about 100 ° C, preferably between room temperature and 85 ° C. the amount of the polyhydric alcohol (or, conversely, the amount of antiperspirant salt) must be that amount which will provide, after step (c) of evaporation, the desired concentration of antiperspirant salt in the recovered polyhydric alcohol solution. In general, it is preferred to use an amount of polyhydric alcohol in step (b) which will provide a mixed solution having a weight ratio of antiperspirant polyhydric alcohol salt of from about 1: 4 to about 1.2: 1, preferably about 1: 3 to approximately 1: 1. After the addition of the polyhydric alcohol, the mixed solution is subjected to evaporation conditions in step (c) to remove most, if not all, of the water not bound to provide a liquid polyhydric alcohol solution, containing about 20 to 50%, preferably about 30 to 47%, of antiperspirant salt of improved efficiency and about 2 to 16%, preferably about 4 to 12%, of water (not bound as measured by the Karl Fischer grinding), with the rest that is polyhydric alcohol. The evaporation step must be carried out under conditions such that the improved efficiency state of the antiperspirant salt, as evidenced by the ratio of area from peak 4 to peak 3 in HPLC), is substantially maintained. In this way, it is generally important that the salt is not exposed to high temperature conditions for any significant duration of time. Accordingly, the evaporation step is preferably carried under vacuum, typically under 150 mm Hg (absolute pressure), preferably about 5 up to about 70 mm Hg. (absolute pressure) and at temperatures below 110 ° C, preferably about 20 ° to about 85 ° C. Obviously, the greater the vacuum (that is, the lower the absolute pressure), the lower the temperature that can be used to achieve the necessary degree of water evaporation within a relatively short time. While the evaporation step can be carried out in any suitable type of vacuum evaporation equipment, the use of rotary vacuum evaporation or instantaneous vacuum evaporation is especially preferred. To minimize the degree of reversion of the improved salt to the unimproved form during the evaporation step, it is important to complete the conversion of a given aliquot of the mixed solution (i.e., the solution before evaporation) to the alcohol solution. polyhydric recovered in the shortest possible time. When relatively large amounts of material (i.e., amounts of 100 liters or more (to be subjected to evaporation, it is preferred to carry out evaporation in a continuous manner, such as, for example, by continuously feeding portions of the mixed solution. At the entrance of a vacuum evaporator and removing the desired solution of polyhydric alcohol from the evaporator outlet, it is possible to complete the conversion of a given aliquot of the solution in less than four hours. The evaporator's antiperspirant salt should be approximately three hours or less.The skilled person should have no difficulty selecting the appropriate equipment to carry out rapid evaporation as described.It is also possible to carry out the process described above with several variations In one variation, the aqueous salt solution provided in step (a) can be concentrated (e.g. n a vacuum evaporator) to approximately a salt concentration of 40 to 50% until the addition of the polyhydric alcohol solution in step (b). If zirconium salt is to be added, it can be added either before or preferably after this concentration step. If this procedure is followed, it is very important that steps (b) and (c) are carried out as quickly as possible to avoid any deterioration in the ratio of peak 4 to peak 3. This is because the solution of Higher concentration salt is much more prone to reversion to unimproved state. In another variation, it is possible to add a solution of zirconium salt, aqueous in an amount to provide the necessary ratio of Al: Zr either (i) to the mixed solution after the liquid polyhydric alcohol according to step (b) or (ii) has been added to the liquid polyhydric alcohol before it is added according to step (b). In this way, when an aluminum-zirconium complex is desired in the final product, the zirconium salt can be added at any stage before the evaporation step (c).

It is preferred that the polyhydric alcohol solution of the antiperspirant salt of improved efficiency which is recovered in the process of the present invention retains substantially the same degree of improved efficiency in the salt as it was when the salt was prepared. That is, the improved efficiency salt when reconstituted as a 10% aqueous solution, should produce a chromatogram in HPLC, (as described, for example, in US 5,330,751), wherein at least 70%, preferably at least 80%, the aluminum is contained in two successive peaks, conveniently labeled peaks 3 and 4, wherein the ratio of the area under the peak 4 to the area under the peak 3 is at least 0.5, preferably at least 0.7, and in the most preferably at least 0.9 or greater. The 10% aqueous salt solution which is subjected to the chromatographic analysis can be prepared either by diluting the polyhydric alcohol solution with sufficient water to form a 10% aqueous salt solution, or by precipitating the salt from the polyhydric alcohol by the addition of acetone, then re-dissolving the water salt at a concentration of 10%. The method of the present invention is particularly advantageous for the preparation of improved efficiency polyhydric alcohol solutions of aluminum-zirconium antiperspirant salts, preferably salts of aluminum-zirconium hydrochloride containing high levels of glycinate salts, such as sodium glycinate. or zinc, which increases the pH of the antiperspirant. That is, the pH of the recovered solution (when measured after the addition of an equal part of distilled water) will fall within the range of about 4.1 to 5.0, preferably about 4.4 to 5.0, when a sufficient amount of water is added. additional glycinate, alkaline salt during the process, typically a sufficient amount to bring the total ratio Gly: Zr to about 1.3 or higher, preferably from about 1.5: 1 to about 4: 1, most preferably about 1.5: 1 up to about 3: 1. By glycinate salt, alkaline is meant any metal glycinate salt which is soluble in the polyhydric alcohol and water and which partially neutralizes the acidity of the antiperspirant salt without otherwise causing any reduction in the clarity of the final product. Preferred alkali glycinates are sodium, potassium and zinc glycinate.

In order to manufacture antiperspirant solutions of the glycine content in accordance with the present invention, the order of addition of the various components is critical in order to avoid precipitation of the salt. First, an aqueous solution of alkali glycinate, such as 50% sodium glycinate, is added to the polyhydric alcohol, typically propylene glycol, before the addition of the antiperspirant salt components. To this solution is added an aqueous solution of zirconium hydroxychloruroglycinate (typically a 50% solution with a Gly: Zr ratio of about 1: 1). Then, an aqueous solution of aluminum hydrochloride of improved efficiency (typically ACH 'at 10%) is added. This solution is then subjected to evaporation under vacuum as previously described to remove most of the water, providing a solution of polyhydric alcohol containing approximately 20 to 50% by weight of aluminum zirconium hydrochloride glycinate (Gly: Zr ratio). from about 1.5: 1 to 4: 1), and from 2 to 16% of water, with a pH between about 4.1 and 5.0 when diluted with an equal portion of water. It should be noted that the reference throughout this application to percent antiperspirant weight is proposed to be calculated as the weight percent of the salt excluding the bound water and glycine or glycinate according to the normal industry method conventional. For reference purposes, the calculation of the weight percent of 1 antiperspirant salt according to the normal method compares with the new calculation of U.S.P. as follows: SALT METHOD NORMAL USP METHOD Al-Zr-Gly in Propylene Glycol (Ex 1) 46.7% 35.8% EXAMPLE 1 An aqueous 50% aqueous aluminum hydrochloride (ACH) solution is diluted with water to form a 10% ACH solution and this solution is heated to about 80 ° C for about 16 to 17 hours to form the salt solution of improved efficiency (ACH '). To 1350 g of this 10% ACH 'solution was added 185 g of zirconium hydroxychloride glycinate (ZHC gly solution, 50% aqueous). To this solution, 271 g of propylene glycol were added and the combined solution was evaporated on a Buchi RE-111 vacuum rotary evaporator at approximately 140 mm Hg (start) up to 20 mm Hg. (end) (absolute pressure) and approximately 60-72 ° C (residence time between approximately 3.5 to 4 hours), to provide a clear solution comprising 44.8% propylene glycol, 46.7% tetrachlorohydrex-aluminum glycine-zirconium (more than 80% of aluminum in peaks 3 and 4 with an area ratio in peak 4 to peak 3 of 1.0), and 8.5% of water.

EXAMPLE 2 To 109.4 kg (241 pounds) of 10% ACH 'solution (prepared as in Example 1) were added 14.5 kg (32 pounds) of ZHC-gly solution (50%), then 58.6 kg (129 pounds) of propylene glycol. The combined solution was preheated to 70-75 ° C and fed continuously to approximately 3-4 gallons / hr in a JH-type flash evaporator (APV Crepaco Inc., Tonawanda, NY; modified evaporator when mounted to the top of the chamber instantaneous a 3-foot rectification tower filled with approximately 2.5 feet of Berl 0.5-inch ceramic shoe) maintained at approximately 60 mm Hg (absolute pressure) from which a clear solution comprising 60.5 was removed at approximately 1 gallon / hour % of propylene glycol, 33.7% of aluminum-zirconium tetrachlorohydrex-glycine of improved efficiency (more than 80% of aluminum in peaks 3 and 4 with the area ratio of peak 4 to peak 3 of 1.1), and 5.8% of water . The average residence time of an aliquot of solution in the evaporator was approximately 3 hours.

EXAMPLE 3 To 1640 g of the hot 10% ACH 'solution (prepared as in Example 1) was added 360 g of propylene glycol and the combined solution was evaporated in a Buchi RE-111 vacuum rotary evaporator at approximately 140 mm Hg ( start) up to 20 mm Hg (end) (absolute pressure) and approximately 46-72 ° C (residence time of approximately 3.5 to 4 hours) to provide a clear solution comprising 62.7% propylene glycol, 30.3% aluminum hydrochloride improved (80% aluminum) at peaks 3 and 4 with area ratio from peak 4 to peak 3 from 1.37), and 7.0% water.

EXAMPLE 4 A 50% sodium glycinate solution was prepared by mixing 77., 6 kg (171 pounds) of 50% NaOH with 30.8 kg (67.8 pounds) of water, then adding 72.8 kg (160.3 pounds) of glycine (molar ratio 1: 1 glycine to NaOH), the temperature increasing from 25 ° to 30 ° C, then from 30 ° to 35 ° C, after the first and second addition, respectively. To 46.9 kg (103.3 pounds) of propylene glycol was added 3.5 kg (7.8 pounds of 50% sodium glycinate and a solution was mixed for 10 minutes) To this solution was added 15.4 kg (33.9 pounds) of zirconium hydroxychloride glycinate ( 50% aqueous ZHC-gli solution, Gly: Zr ratio of approximately 1: 1).

After mixing this solution for approximately 10 minutes, 115.8 kg were added (255 pounds) of the 10% ACH 'solution (prepared as in Example 1) and mixed for about 10 minutes. This solution was preheated to about 70 ° to 75 ° C, and continuously fed to a JHC type flash evaporator as described in Example 2. A clear solution comprising 65 or propylene glycol, 35% tetrachlorohydre-glycine is obtained. aluminum-zirconium of improved efficiency (more than 80% aluminum at peaks 3 and 4 with an area ratio of peak 4 peak 3 greater than 1 and the Gly: Zr ratio of approximately 1.6: 1), and 5% water . The pH of a sample of this solution diluted with an equal portion of distilled water was approximately 4.7.

It is noted that in relation to this date, the best method known by the applicant to carry out the present invention is that which is clear from the present description of the invention. Having described the invention as above, the content of the following is claimed as property:

Claims (23)

1. A process for preparing an aluminum antiperspirant salt solution of improved efficiency in a polyhydric alcohol, characterized in that it comprises: (a) providing an aqueous solution consisting essentially of from about 5% to about 20% by weight of an antiperspirant aluminum salt of improved efficiency, in water, the improved efficiency antiperspirant aluminum salt that has been prepared in situ without drying to a solid powder; (b) mixing the aqueous solution with a sufficient amount of a liquid polyhydric alcohol to provide a mixed solution having a weight ratio of antiperspirant salt to polyhydric alcohol of from about 1: 4 to about 1.2: 1; and (c) rapidly evaporating the water from the mixed solution under vacuum to provide a liquid polyhydric alcohol solution containing about 20 to 50% aluminum antiperspirant salt of improved efficiency and about 20 to 16% water, with the rest that is polyhydric alcohol.

2. The process according to claim 1, organic layer the aluminum antiperspirant salt of improved efficiency is a mixture or complex of Al2 (OH) and Zro (OH) 2-PbYb wherein X is Cl, Br, I, or N0, a is from about 0.3 to about 4, Y is Cl, Br, I, N03 or S04, b is about 0.8 to about 2, p is the valence of Y, and an Al: Zr ratio is about 1.7 to about 12.5.

3. The process according to claim 2, characterized in that the polyhydric alcohol is selected from the group consisting of propylene glycol, butylene glycol, diethylene glycol, dipropylene glycol, glycerin, sorbitol and mixtures thereof.

4. The process according to claim 3, characterized in that the aluminum antiperspirant salt of improved efficiency is aluminum-zirconium hydrochloride.

5. The process according to claim 4, characterized in that the aqueous solution of aluminum antiperspirant salt of improved efficiency is prepared by heating a 5 to 18% aqueous solution of aluminum hydrochloride at a sufficient temperature and for a sufficient time to provide a area ratio from peak 4 to peak 3 in HPLC of at least 0.7 with at least 70% of the aluminum enid in these peaks, then add zirconyl hydroxychloride to this solution in an amount to provide an Al: Zr ratio of approximately 2 up to about 8.

6. The process according to claim 5, characterized in that the aluminum antiperspirant salt of improved efficiency has an area ratio of peak 4 to peak 3 in HPCL of 0.9 or more both after step (a) and after step (c) .

7. The process according to claim 1, characterized in that the aluminum antiperspirant salt of improved efficiency in step (a) is Al2 (0H) 6-aXa wherein X is Cl, Br, I, or N03, is already approximately 0.3 to approximately 4.

8. The process according to claim 7, characterized in that the polyhydric alcohol is selected from the group consisting of propylene glycol, butylene glycol, diethylene glycol, dipropylene glycol, glycerin, sorbitol and mixtures thereof.

9. The process according to claim 8, characterized in that the aluminum antiperspirant salt of improved efficiency is aluminum chlorohydrate.

10. The process according to claim 8, characterized in that before the step (c) an aqueous zirconium salt solution is added in an amount to provide an Al: Zr ratio of from about 1.7 to about 12.5 (i) to the mixed solution after the liquid polyhydric alcohol has been mixed with the solution aqueous according to step (b) or (ii) to the liquid polyhydric alcohol before it is mixed with the aqueous solution according to step (b), wherein the zirconium salt has the formula Zro (OH) 2- pbYb where Y is Cl, Br, I, N03, or S04, b is approximately 0.8 to 2, and p is the valence of Y.

11. The process according to claim 10, characterized in that the aluminum antiperspirant salt of improved efficiency is aluminum chlorohydrate and the zirconium salt is zirconyl hydroxychloride.

12. The process according to claim 9, characterized in that the aqueous solution of aluminum antiperspirant salt of improved efficiency is prepared by (i) heating a 5 to 18% aqueous solution of aluminum hydrochloride at a sufficient temperature and for a sufficient time to provide an area ratio of peak 4 to peak 3 in HPLC of at least 0.7 with at least 70% of the aluminum contained in these peaks or (ii) to react the aluminum metal with aluminum chloride or hydrochloric acid in water to a temperature of about 50 ° to 100 ° C, the concentration of the reactants which is such as to provide an aqueous solution of aluminum chlorohydrate of from about 10 to about 20% with an area ratio of peak 4 to peak 3 in HPLC of minus 0.7 with at least 70% of the aluminum contained in these peaks.

13. The process according to claim 12, characterized in that before the step (b) the aqueous solution of the improved antiperspirant aluminum salt rapidly concentrates to about 40 to 50% salt concentration, and steps (b) and (c) are carried out sufficiently quickly thereafter so that the aluminum antiperspirant salt of improved efficiency retains an area ratio of peak 4 to peak 3 in HPLC of at least 0.7.

14. The process according to claim 12, characterized in that before the step (c) a solution of aqueous zirconium hydroxychloride is added in an amount to provide an Al: Zr ratio of from about 2 to about 8 (i) to the mixed solution after the liquid polyhydric alcohol has been mixed with the solution of aluminum hydrochloride, aqueous according to step (b) or (ii) to the liquid polyhydric alcohol before it is mixed with the aqueous aluminum hydrochloride solution, in accordance with step (b)

15. The process according to claim 14, characterized in that the aluminum antiperspirant salt of improved efficiency has an area ratio of peak 4 to peak 3 in HPLC of 0.9 or more both after step (a) and step (c).

16. The process according to claim 1, 3, 4, 6, 8, 9, 11, 12 or 15, characterized in that step (c) is performed at about 5 to about 70 mm Hg (absolute pressure) of about 20 ° up to about 85 ° C.

17. The process according to claim 16, characterized in that step (c) is performed in a continuous manner by continuously adding the mixed solution to the inlet of a vacuum evaporator and removing the polyhydric alcohol solution from the outlet of the vacuum evaporator. .

18. The process according to claim 16, characterized in that step (c) is carried out such that the conversion of an aliquot of mixed solution to the polyhydric alcohol solution is completed in less than four hours.

19. The process according to claim 14, characterized in that the liquid polyhydric alcohol contains an alkaline glycinate, solubilized in an amount sufficient to provide a total Gly: Zr ratio in the product recovered from about 1.3: 1 to about 4: 1 and the solution Aqueous zirconium hydroxychloride is added to the liquid polyhydric alcohol before it is mixed with the aqueous solution of aluminum chlorohydrate according to step (b).

20. The process according to claim 19, characterized in that the alkali glycinate is sodium glycinate, potassium glycinate or zinc glycinate.

21. A process for preparing an aluminum-zirconium antiperspirant salt solution of improved efficiency. in a polyhydric alcohol, characterized in that it comprises: (a) providing a liquid polyhydric alcohol containing a solubilized alkali glycinate, the amount of the solubilized alkali glycinate which is sufficient to provide a total Gly: Zr ratio of about 1.3: 1 to about 4: 1 in the recovered product; (b) providing a first aqueous solution consisting essentially of about 40% to about 50% glycinate of zirconium hydroxychloride in water; (c) providing a second aqueous solution consisting essentially of about 5% to about 20% by weight of an aluminum chlorohydrate of improved efficiency in water, the improved efficiency aluminum chlorohydrate which has been prepared in situ without drying to a solid powder and having an area ratio of peak 4 to peak 3 in HPLC of at least 0.7 with at least 70% of the aluminum contained in the peaks; (d) mixing the first aqueous solution with the liquid polyhydric alcohol to provide a first mixed solution; (e) mixing the second aqueous solution with the first mixed solution to provide a second mixed solution; wherein the amount of each of components (a), (b) and (c) is such as to provide a second mixed solution having a weight ratio of aluminum-zirconium hydrochloride to polyhydric alcohol of about 1: 4 to about 1.2: 1 and an Al: Zr ratio of from about 2 to about 8; and (f) rapidly evaporating the water from the second mixed solution under vacuum to provide a liquid polyhydric alcohol solution containing about 20 to 50% aluminum-zirconium hydrochloride glycinate of improved efficiency and about 2 to 16% water, with the remainder being polyhydric alcohol, aluminum zirconium hydrochloride glycinate having an area ratio of peak 4 to peak 3 in HPLC of at least 0.7 with at least 70% of the aluminum contained in the peaks, a Gly: Zr total ratio of about 1.3: 1 to about 4: 1, and a pH of about 4.1 to about 5.0.

22. The product manufactured according to the process of claims 4, 9, 11 or 21.

23. The product manufactured according to the process of claim 16. SUMMARY OF THE INVENTION The present invention comprises a process for preparing a solution of an aluminum antiperspirant salt of improved efficiency in a polyhydric alcohol by (a) providing an aqueous solution consisting essentially of about 5% to about 19% by weight of an aluminum antiperspirant salt. of improved efficiency in water, the antiperspirant salt of aluminum that has been prepared in situ without drying to a solid powder; (b) mixing the aqueous solution with a sufficient amount of a liquid polyhydric alcohol, to provide a mixed solution having a ratio of antiperspirant salt to polyhydric alcohol of from about 1: 4 to about 1.2: 1; and rapidly evaporating the water from the mixed solution under vacuum to provide a final liquid solution of polyhydric alcohol containing about 20 to 50% aluminum antiperspirant salt of improved efficiency and about 2 to 16% water, with the remainder being polyhydric alcohol. A glycinate, alkaline salt, such as sodium, potassium or zinc glycinate can be added to the polyhydric alcohol prior to the addition of the antiperspirant salt solution in order to increase the pH of the recovered product to about 4.1 to 5.0