Abstract:
A cleaning tablet comprising a hydrogen-bonded complex of poly(N-vinyl pyrrolidone) containing, by weight, about 15-20 wt. % H 2 O 2 , and ingredients capable of producing an effervescent effect in aqueous solution by release of carbon dioxide therefrom which comprises an alkali carbonate and/or bicarbonate base and an organic acid.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     The present application claims the benefit of U.S. Provisional Application Ser. No. 60/788,454, filed on Mar. 31, 2006, which is incorporated herein by reference thereto. 
     
    
     FIELD OF THE INVENTION  
       [0002]     This invention relates to cleaning products, and, more particularly to tablets having a high concentration of stable peroxide and ingredients capable of producing an effervescent effect upon dissolution in aqueous solution.  
       BACKGROUND OF THE INVENTION  
       [0003]     Industry has trended toward oxygen-cleaning products for spot cleaning application, particularly stable liquid peroxide-containing cleaning formulations. Also it is desired to introduce the peroxide in a tablet which can be dissolved in an aqueous solution to form the peroxide cleaning composition. A product which can provide effervescence during cleaning is considered an advantage.  
       SUMMARY OF THE INVENTION  
       [0004]     A cleaning tablet comprising a hydrogen-bonded complex of poly(N-vinyl pyrrolidone) containing, by weight, about 15-20 wt. % H 2 O 2 , and ingredients capable of producing an effervescent effect in aqueous solution by release of carbon dioxide therefrom which comprises an alkali carbonate and/or bicarbonate base and an organic acid.  
         [0005]     A cleaning tablet which contains about 6-11 wt. % hydrogen peroxide.  
         [0006]     A cleaning tablet wherein said alkali carbonate and/or bicarbonate is selected from sodium carbonate or potassium carbonate, sodium bicarbonate and potassium bicarbonate, and said organic acid is selected from citric, malic, tartaric, adipic and fumaric acid.  
         [0007]     A cleaning tablet wherein the wt. ratio of base to acid thereon is about 1:1.  
         [0008]     A cleaning tablet which also includes a disintegrant ingredient.  
         [0009]     A cleaning tablet wherein said disintegrant is Polyclar Super R or Disintex-75.  
         [0010]     A cleaning tablet having a rapid dissolution time in aqueous solution. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0011]     In one embodiment of the invention there is provided herein a peroxide tablet containing capable of producing an effervescent effect upon dissolution in water. A suitable peroxide source is Peroxydone® K-30 (ISP) which is a hydrogen bonded complex of poly(N-vinyl pyrrolidone) containing 15-20 wt. % H 2 O 2 . Suitably the tablet contains a high concentration of Peroxydone® K-30, preferably about 40-50 wt. % Peroxydone® K-30. The tablet also contains ingredients which can effervesce when dissolved in water. Suitable of such ingredients are a base, e.g. an alkali metal carbonate and/or bicarbonate, e.g. sodium carbonate, potassium carbonate and/or sodium bicarbonate or potassium bicarbonate, and an organic acid, e.g. citric, malic, tartaric adipic or tartaric acid. Preferably such base and acid are present in about a 1:1 wt. ratio. When the tablet is dissolved the interaction of base and acid results in the release of carbon dioxide, subsequently increases the rate of disintegration of the Peroxydone® K-30 and other ingredients present in the tablet.  
         [0000]     Dissolution Test  
         [0012]     Each tablet contained 1 g formulation, which was hand mixed.  
         [0013]     The powder was compressed into a tablet using a pressure of 800 lb for the 1 g tablet, and a dwell time of 1 second on a Carver Automated tablet press.  
         [0014]     Tablet was placed in a mesh-wire basket and then submerged in 800 mL of distilled water at 25° C. It was kept in the water until complete dissolution or a maximum of 10 minutes.  
         [0015]     For tablets that did not completely disintegrate before 10 min, a second mass was taken of the dry residue and a dissolution rate (g/min) was calculated.  
         [0000]     Calculation of Dissolution Rate 
 
Dissolution Rate(g/min)=(Tablet Initial Weight(g) −Tablet Final Weight(g) )/Dissolution Time (min.) 
 
 Results and Discussion 
 
         [0016]     An effervescent tablet formulation containing a balanced ratio of acid with sodium bicarbonate was used to formulate at least 40-50% Peroxydone® K-30 with other ingredients. Formulation is compressed into a tablet and it is tested for dissolution. While the tablet dissolved in water, the interaction of the acid and base resulted in the release of carbon dioxide, subsequently increased the rate of disintegration of the Peroxydone K-30 and other additives. Concentrations of ingredients were used in wt % and the abbreviations of all ingredients used in these tablet formulations are listed in Table I.  
                       TABLE I                                       PK30 - Peroxydone K-30           NaBC - Sodium Bicarbonate           CC - Calcium Carbonate           CA - Citric Acid           TA - Tartaric Acid           NaCl - Sodium Chloride           SLS - Sodium Lauryl Sulfate           EW20 - EasyWet-20           MA - Malic Acid           FA - Fumaric Acid           AA - Alginic Acid           CS - Calcium Silicates           SS - Sodium Silicates           CAce - Calcium Acetate           EG - Ethylene glycol           UCon Lubricant 50-HB-660 - Dow           PSR - Polyclar Super R           D-75 - Disintex-75           D-200 - Disintex-200           PEG600 - Polyethylene glycol           PG - Propylene glycol           KAce - Potassium Acetate           Gly - Glycerine                      
 
         [0017]     The tablet test was conducted using a wide range of additives in various ratios to formulate the Peroxydone K-30 tablets. Peroxydone K-30 was tableted at a concentration of 50 wt. % and 40 wt. %. Tablets formulated with 50 wt. % PK-30 gave slow dissolution times, with a maximum dissolution of 5.15 m·s. The results are listed in Table II. The test tablets did not include any disintegrants in the formulation.  
                                           TABLE II                           (50% Peroxydone)                Time   Rate       Composition   (min · sec)   (g/min)                    PK-30(50%) + CC-Aldrich(30%) + TA(20%)   &gt;10   0.068       PK-30(50%) + NaBC(30%) + TA(15%) +   &gt;10   0.095       D-75(5%)       PK-30(50%) + NaBC(30%) + TA(15%) +   &gt;10   0.076       EW20(5%)       PK-30(50%) + NaBC(25%) + TA(25%)   9.1   0.11       PK-30(50%) + NaBC(30%) + TA(15%) +   5.45   0.17       D-75 (2.5%) + PEG600(2.5%)       PK-30(50%) + NaBC(30%) + TA(18%) +   5.3   0.18       PEG600(2%)       PK-30(50%) + NaBC(30%) + TA(15%) +   5.15   0.19       PEG600(5%)       PK-30(50%) + NaBC(25%) + TA(15%) +   5.45   0.17       PEG600(10%)       Tablet weights were 1 g.                  
 
         [0018]     Tablets formulated with 40 wt. % PK-30 gave faster dissolution times, with a maximum dissolution of 1.21 m·s; the results are listed in Table III. Higher amounts of base and acid did not improve dissolution times; a balanced ratio of 1:1 acid to base gave faster dissolution times. To this a disintegrant added tablet improved the dissolution time. Polyclar Super R having a slightly higher particle size is a better disintegrant then Disintex-75 for this particular tablet formulation.  
                                           TABLE III                           (40% Peroxydone)                Time   Rate           (min · sec)   (g/min)                        Composition               PK-30(40%) + NaBC(20%) + TA(20%) +   &gt;10   0.075       SLS (10%) + PEG600(10%)       PK-30(40%) + NaBC(25%) + TA(25%) +   7.2   0.3       Gly(10%)       PK-30(40%) + NaBC(25%) + TA(25%) +   6.15   0.16       UCon(10%)       PK-30(40%) + NaBC(10%) + TA(40%) +   5   0.2       PEG600(10%)       PK-30(40%) + NaBC(15%) + TA(35%) +   3.45   0.27       PEG600(10%)       PK-30(40%) + NaBC(35%) + TA(15%) +   3.36   0.28       PEG600(10%)       PK-30(40%) + NaBC(20%) + TA(30%) +   3.23   0.3       PEG600(10%)       PK-30(40%) + NaBC(25%) + TA(25%) +   3.1   0.32       PG(10%)       PK-30(40%) + NaBC(25%) + TA(12.5%) +   3.2   0.3       MA(12.5%) + PEG600(10%)       Effect of Concentration of Acid and Base       PK-30(40%) + NaBC(35%) + TA(15%) +   3.35   0.26       PEG600(10%)       PK-30(40%) + NaBC(25%) + TA(25%) +   3.12   0.31       PEG600(10%)       PK-30(40%) + NaBC(20%) + TA(30%) +   3.23   0.3       PEG600(10%)       PK-30(40%) + NaBC(15%) + TA(35%) +   3.45   0.27       PEG600(10%)       PK-30(40%) + NaBC(10%) + TA(40%) +   5   0.2       PEG600(10%)       Tablet with Disintegrant       PK-30(40%) + NaBC(25%) + TA(20%) +   2.3   0.4       D-75(10%) + PEG600(5%)       PK-30(40%) + NaBC(25%) + Tartaric   4   0.25       Acid(20%) + D-200(10%) + PEG600(5%)       PK-30(40%) + NaBC(25%) + TA(20%) +   1.27   0.69       PSR(10%) + PEG600(5%)                  
 
         [0019]     The third tablet performed best (1.27 m·sec) above repeated 5 times for data consistency. The average dissolution of 5 such tablets was 1.21 m·s. These results are given in Table IV.  
                             TABLE IV                           (40% Peroxydone)                Time   Rate       Composition   (min · sec)   (g/min)               PK-30(40%) + NaBC(25%) + TA(20%) +   1.27   0.69       PSR(10%) + PEG600(5%)