Abstract:
The present invention relates to oral compositions in the form of microcapsules which reduce oral bacteria and provide long lasting breath protection.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This is a continuation of application Ser. No. 07/805,432, filed on Dec. 11, 1991, now abandoned. 
    
    
     TECHNICAL FIELD 
     The present invention relates to oral compositions in the form of microcapsules which reduce oral bacteria and provide long lasting breath protection. 
     BACKGROUND OF THE INVENTION 
     The use of breath control compositions such as breath mints, mouthwashes, chewing gums, etc. is widespread in most of the developed countries of the world. Another form which has been used are microcapsules containing a flavorant or other breath protection agent. These executions have acceptance due not only to their usefulness away from a place to expectorate mouthwashes but also due to the fact that they can be swallowed when the user does not need any more of the actives or doesn&#39;t want the microcapsule in the mouth any longer. 
     Although microcapsules have been used, there are problems associated with incorporating certain breath protection agents/antimicrobials into the core. Oftentimes the wall of the microcapsule may develop imperfections and cause loss of the contents prematurely. Additionally, the actives may not be easily solubilized in the materials usually present in the core. 
     The prior art discloses a variety of means for providing breath protection and reducing oral bacteria. Included among such means are sprays disclosed in U.S. Pat. No. 3,431,208, Mar. 4, 1969 to Bailey. Particles containing an adhesive member are disclosed in U.S. Pat. No. 3,911,099, Oct. 7, 1975 to Den Foney et al. Another form is a mouthwash concentrate in a unit dosage cup as disclosed in U.S. Pat. No. 4,312,889, Jan. 26, 1982 to Melsheimer. All of these references are incorporated herein by reference. 
     The present inventors have found that by incorporating the breath control/antimicrobial actives into the core of the microcapsule along with organic diluents, problems associated with other microcapsule executions can be avoided. 
     It is therefore an object of the present invention to provide improved microcapsules. 
     It is another object of the present invention to provide microcapsules which provide improved breath control and reduce oral bacteria. 
     It is still another object of the present invention to provide improved methods of providing breath control and reducing oral bacteria. 
     These and other objects will become more apparent from the detailed description which follows. 
     All percentages and ratios used herein are by weight unless otherwise specified. Additionally, all measurements are made at 25° C. unless otherwise specified. 
     SUMMARY OF THE INVENTION 
     The present invention in one of its aspects relates to microcapsules which contain breath control actives/antimicrobials in the core of the microcapsule along with an organic diluent as well as in the shell of the microcapsule. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The essential as well as optional components of the capsules of the present invention are described in the following paragraphs. 
     Capsule Shell Material: 
     The shell material of the microcapsules of the present invention can be any materials which are suitable for ingestion as well as retention in the oral cavity. Materials which are suitable include gelatin, polyvinyl alcohols, waxes, gums, sucrose esters and sugar candy type materials used in cough drops and mints, for example. 
     The shell material is used to form any of a wide variety of shapes such as spheres, oblong shapes, disks, puffed squares and cylinders. The shell thickness is preferably in the range of about 30 um to about 2 mm, preferably from about 70 um to about 110 um. If the microcapsules are spherical, the particle diameter is generally in the range of from about 2 mm to about 9 mm, preferably from about 3 mm to about 7 mm. 
     Breath Control Agents/Antimicrobials Present in the Core and in the Shell Material: 
     The breath control agents used in the cores of the microcapsules include quaternary ammonium salts such as pyridinium salts (e.g., cetyl pyridinium chloride), domiphen bromide, other cationic materials such as chlorhexidine salts, zinc salts and copper salts. Other organic agents such as triclosan and other noncationic water insoluble agents are also useful herein. Such materials are disclosed in U.S. Pat. No. 5,043,154, Aug. 27, 1991, incorporated by reference herein. 
     These breath control/antimicrobial agents are used in an amount of from about 0.001% to about 2%, preferably from about 0.005% to about 1% of the total core contents. 
     Dispersed within the shell material may be the same agents at the same concentrations. 
     Diluents for Use in Microcapsule Core: 
     The solubilizing agent for the breath control/antimicrobial agents used in the cores of the present microcapsules can be any of a number of materials. Preferred are oils such as corn, olive, rapeseed, sesame, peanut or sunflower. Other preferred materials are triglycerides such as Captex 300 and polyethylene glycols such as PEG 400. These are used in an amount of from about 20% to about 80%, preferably from about 35% to about 70% of the total capsule weight. 
     Additional Agents Suitable for Use in the Core of Capsule: 
     The core of the microcapsules of this invention may contain any number of additional materials to provide additional efficacy and/or sensory perceptions. Such agents may include flavoring agents such as thymol, eucalyptol, menthol, methyl salicylate or witch hazel. These agents are used in an amount of from about 0.1% to about 25%, preferably from about 10% to about 15% of the total capsule weight. 
     In addition, a variety of sweetening agents such as sugars, corn syrups, saccharin or aspartame may also be included in the core. These agents are used in an amount of from about 0.1% to about 5%, preferably from about 0.35% to about 0.5% of the total capsule weight. 
     Method of Manufacture: 
     The capsules of the present invention can be made using a variety of techniques. One method is described after the following examples. 
     Industrial Applicability: 
     The capsules of the present invention are used by placing the capsules into the mouth and retaining them therein for a period sufficient to provide the desired effect. 
     The following examples further describe and demonstrate preferred embodiments within the scope of the present invention. The examples are given solely for the purposes of illustration and are not to be construed as illustrative of limitations of this invention. Many variations thereof are possible without departing from the invention&#39;s spirit and scope. 
     EXAMPLES 1-4 
     The following compositions/capsules are representative of the present invention. 
     
         ______________________________________      Weight %Component    1       2       3     4     5______________________________________Gelatin      12.578  12.328  12.578                              17.578                                    10.360Sorbitol Solution        2.046   2.05    2.046 2.046 2.590(70% Aqueous)Saccharin    0.372   0.500   0.372 0.450 0.538FD&amp;C Blue #1 0.002   0.002   0.002 --    0.013FD&amp;C Yellow #5        0.002   --      0.002 0.004 --Captex 300.sup.1        72.140  70.00   71.925                              66.142                                    3.801Flavor       12.750  15.00   12.75 13.500                                    5.986Cetyl Pyridinium.sup.2        0.100   --      --    --    0.133ChlorideDomiphen Bromide        0.010   --      --    --    0.013Chlorhexidine        --      0.12    --    --    --ZnCl.sub.2   --      --      0.025 --    --Sodium Lauryl Sulfate        --      --      0.300 --    --Triclosan    --      --      --    0.28  --Polyethylene glycol        --      --      --    --    35.082400Sucrose Acetate        --      --      --    --    38.846IsobutyrateWater        --      --      --    --    2.636______________________________________ .sup.1 Captex 300 is a triglyceride supplied by Capitol City Product, Columbus, Ohio. .sup.2 This amount includes that in the gelatin shell as well as in the core. 
    
     The above compositions are prepared by mixing the components of the core in one container and the components of the shell(s) in another container. The shell(s) materials are heated to provide a fluid medium. The core and shell(s) materials are then pumped separately to a two or three fluid nozzle submerged in an organic carrier medium. The capsules formed are allowed to cool and stiffen. They are then denatured and separated for further handling. 
     In the above compositions any of a wide variety of other shell materials, breath control agents, sweeteners as well as other components may be used in place of or in combination with the components listed above. These are listed on pages 2 and 3.