Stabilized aqueous acidic antiperspirant compositions and related methods

Abstract

A method for inhibiting loss of gel strength in an acidic aqueous based solid antiperspirant composition gelled with one or more polysaccharides comprising adding to said composition an effective amount of a gel degradation inhibitor and an acidic aqueous based solid antiperspirant composition containing at least one phase gelled with one or more polysaccharide gelling agents, wherein the improvement comprises including in the polysaccharide gelled phase at least one gel degradation inhibitor.

We claim:  
     
         1 . A method for inhibiting loss of gel strength in an acidic aqueous based solid antiperspirant composition gelled with one or more polysaccharides comprising adding to said composition an effective amount of a gel degradation inhibitor.  
     
     
         2 . The method of  claim 1  wherein the composition is a water and oil emulsion.  
     
     
         3 . The method of  claim 2  wherein the polysaccharide gelling agents are water soluble and comprise part of the water phase of the emulsion.  
     
     
         4 . The method of  claim 2  wherein the gel degradation inhibitor is water soluble and forms part of the water phase of the emulsion.  
     
     
         5 . The method of  claim 1  wherein the gel degradation inhibitor increases the pH of the antiperspirant composition about ½ to 1 unit.  
     
     
         6 . The method of  claim 1  wherein the composition prior to inclusion of the gel degradation inhibitor is about 3.2 to about 3.5 and after inclusion of the gel degradation inhibitor is about 4.2 to 4.5.  
     
     
         7 . The method of  claim 1  wherein the gel degradation inhibitor is a metal salt.  
     
     
         8 . The method of  claim 7  wherein the metal salt is a metal salt of an amino acid.  
     
     
         9 . A method for preparing an aqueous based antiperspirant composition having improved gel strength comprising the steps of: 
 a) preparing a water phase by combining antiperspirant salts, one or more polysaccharide gellants, a gel degradation inhibitor, and water to form a homogeneous mixture,    b) preparing an oil phase by combining at least one oil with one or more compatible ingredients,    c) emulsifying the water phase and the oil phase to form an emulsion.    
     
     
         10 . The method of  claim 9  wherein the water phase is prepared in two pre-mixtures wherein the first pre-mixture comprises water, antiperspirant salts, a gel degradation inhibitor, and the second pre-mixture comprises water and at least one polysaccharide gellant.  
     
     
         11 . A method for preparing an aqueous based solid antiperspirant composition having improved gel strength comprising the steps of: 
 a) preparing a first aqueous phase comprised of antiperspirant salts, water, and a gel degradation inhibitor and mixing well to form a homogeneous solution,    b) preparing a second aqueous phase comprising water and at least one polysaccharide gellant,    c) preparing an oil phase comprising at least one oil,    d) emulsifying the second aqueous phase (b) into the oil phase (c) to form an emulsion; and    e) emulsifying the first aqueous phase (a) into the mixture of (d) to form a water and oil emulsion solid antiperspirant composition.    
     
     
         12 . The method of  claim 11  wherein the gel degradation inhibitor is one or more metal salts.  
     
     
         13 . The method of  claim 11  wherein the second aqueous phase is heated to form a clear homogeneous solution.  
     
     
         14 . The method of  claim 11  wherein the antiperspirant salts and gel degradation inhibitor are prepared as a pre-mix prior to incorporating into the composition.  
     
     
         15 . An acidic aqueous based solid antiperspirant composition containing at least one phase gelled with one or more polysaccharide gelling agents, wherein the improvement comprises including in the polysaccharide gelled phase at least one gel degradation inhibitor.  
     
     
         16 . The composition of  claim 15  which is a water and oil emulsion.  
     
     
         17 . The composition of  claim 16  wherein the water phase comprises 1-95% by weight of the total composition.  
     
     
         18 . The composition of  claim 17  wherein the oil phase comprises 1-75% by weight of the total composition.  
     
     
         19 . The composition of  claim 18  wherein the polysaccharide gelling agent is a galactan or galactomannan.  
     
     
         20 . The composition of  claim 14  wherein the gel degradation inhibitor is a water soluble metal salt.