Abstract:
The present invention relates to a topical skin care formulation comprised of micronized calcium citrate and salicylic acid. This composition provides a method for treating acne as well as providing for a variety of skin beautification products which are especially applicable to sensitive skin.

Description:
This application is a continuation-in-part, of U.S. patent application Ser. No. 07/404,660 filed Sep. 8, 1989. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a topical skin care formulation comprised of micronized calcium citrate and salicylic acid. This composition provides a method for treating acne as well as providing for a variety of skin beautification products which are especially applicable to sensitive skin. 
     BACKGROUND OF THE INVENTION 
     Skin care formulations have been previously formulated utilizing a great variety of components including salicylic acid. For example, U.S. Pat. Nos. 3,265,571, 4,318,907, 2,942,008 and 3,236,730 all disclose formulations which incorporate salicylic acid in their acne treating compositions calcium citrate is also found in a variety of products and is included in the &#34;Generally Regarded as Safe&#34; (GRAS) classification by U.S. Food and Drug Administration. It has been utilized as a source of calcium for humans rather than as an active ingredient in medications. An exception to its use as a medicament is U.S. Pat. No. 2,719,811 which discloses the use of a variety of water soluble metal complexes including calcium citrate which is used as a stimulating agent for cellular respiration. 
     The applicant of the instant formulation holds U.S. Pat. No. 4,393,045, which is a process in which the lining of mollusk shells were admixed with the extrudate of citric acid and was found to be effective in the treatment of skin care symptoms such as acne. After the issuance of the above patent, applicant found that it would be advantageous to include a keratolytic agent such as salicylic acid in the composition. The inventor found that by combining the calcium citrate with salicylic acid in the manner shown herein, that the results effected by each ingredient alone, were enhanced, not only as to effectiveness but also as the variety of application for skin care and topical analgesic products. 
     No patents to the knowledge of applicant have recognized the synergistic combination of calcium citrate and salicylic acid in the formulation of skin care and beautification products especially in regard to their utility in the cosmetic, detergent and topical remedy treatment of sensitive skin. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The skin care composition of the present invention are characterized by the active ingredients calcium citrate and salicylic acid. This composition can be applied topically in the form of creams, masques, ointments, emulsions, lotions, gels, soaps, soap-free medication cleansing bars and the like. 
     The calcium citrate component of the instant formulation is effective only when utilized in the form of a micronized powder. The use of the calcium citrate alone, in such micronized state was found to be an effective treatment of skin care disorders such as acne. Applicant discovered that by blending of calcium citrate and salicylic acid, in the percentages shown in the examples, it produced results more effective as to each ingredient utilized alone. The characteristics of the preferred micronized powder are displayed in Table 1 for a tricalcium citrate powder which is commercially available form numerous sources. 
     
                       TABLE 1______________________________________Tricalcium Citrate USPXX Powder______________________________________Molecular Formula:            Ca.sub.3 (C.sub.6 H.sub.5 O.sub.7).sub.2 4H.sub.2 OMolecular Weight:            570.50Appearance:      White PowderIdentity:        Shows characteristic reactions            of Calcium and CitratesSolubility:      Very poorly soluble in water;            soluble in diluted            hydrochloric acid and nitric            acidInsoluble Parts of            Max. 0.05%Hydrochloric Acid:Calcium Oxide (CaCO.sub.3):            TraceHeavy Metals (as Pb):            Max. 0.002%Loss on Drying:  Max. 0.0006%Assay:           97.5-101.0% Ca.sub.3 (C.sub.6 H.sub.5 O.sub.7).sub.2            calculated on the dry matterMesh Size Specification:            94% through a #100 to #200            sieve______________________________________ 
    
     As shown above it was determined to be advantageous to include keratolytic agent in the composition of the present invention. The preferred keratolytic agent for use in the instant invention is salicylic acid. The amount of salicylic acid employed in the skin care formulations of the instant invention can vary according to the specific desired skin care treatment. 
     Topical acne medication and skin beautification formulations for use in the present invention can be applied through the use of any suitable conventional vehicle or carrier. Convenient liquid vehicles which are useful in the application of the instant skin care formulations include water, alcohols, such as methanol, ethanol, propanol and isopropanol, water-alcohol solutions or water-alcohol-polyalkyleneglycol solutions. A convenient vehicle for the administration of the subject skin-treatment formulations of the instant invention is a water-ethanol-ethylene glycol solution having a weight composition of 50% water, 30% ethanol and 20% propyleneglycol. 
     The combination of calcium citrate and salicylic acid provides for a wide variety of skin beautification products. The foremost application of these ingredients is for the preparation of an acne medication. The present invention has additional cosmetic and skin beautification applications as an ingredient in skin moisturizers, sun-screens, pre-shave lotions, after-shave lotions, colognes, soap-free medicated cleansing bars, soaps, deodorants, athlete&#39;s foot and jock itch medications and wart and hard and soft corn removers. The utilization of the skin care formulation ingredients of the present invention in any of these applications is considered within the scope of the instant invention. 
     The compositions that are found to be the most therapeutically effective in the treatment of inflammation of the skin, including acne, is: micronized calcium citrate in an amount ranging from approximately 2 to 50 percent by weight and salicylic acid in an amount ranging from 0.05 to 2 percent by weight of the total composition which includes suitable carriers and the like. 
     Various different cosmetic and therapeutic applications require varying amounts of calcium citrate and salicylic acid according to the desired end product. The typical acne medicaments of the instant invention utilize 2.5% to 50%, preferably 5 to 40% by weight of calcium citrate and 0.05% to 2.0%, preferably 0.5 to 2.0% by weight salicylic acid as active ingredients. 
     Fast acting external analgesics can be formulated utilizing from 2.5% to 97% by weight of calcium citrate and about 0.2 to 2% by weight of salicylic acid. Corn removing agents can be formulated utilizing by weight of 2.5% to 97% calcium citrate and about 1% to 20% by weight of salicylic acid. Each formulation can be admixed with a suitable pharmaceutical carrier as are known in the art. 
     Topical skin treating compositions including sunscreens and non-oily moisturizers advantageously contain 3 to 20% by weight of micronized calcium citrate. These compositions may optionally contain 0.05 to 2% by weight of salicylic acid. 
     The instant delivery system may also include additional fragrance oils, moisturizers, humectants, emollients and other skin care and cosmetic ingredients, such as excipients, colorants, preservatives, diluents and the like. 
     It has been determined that the above components when combined in the ranges of proportions in the following examples synergistically provide skin treating compositions which result in skin beautification. In the examples displaying two part compositions A and B, both parts are suitably blended to produce a final applicable product. All percentages are percents by weight unless otherwise indicated. 
     
         ______________________________________Example 1           % by Weight                    Preferred %______________________________________ACNE MEDICATION - LIQUIDMicronized Calcium Citrate             5 to 20    10from Table 1Salicylic Acid    .05 to 2   .05Water (deionized) 50 to 80   70Ethylalcohol      5 to 20    10ACNE MEDICATION - GELMicronized Calcium Citrate             20 to 35Salicylic Acid    .05 to 2Ethanol           5 to 20Bentonite         Up to 10%Silicone Fluid (e.g., Dow 556)             Up to 10%Hydroxyethyl Cellulose             Up to 5%Water             RemainderACNE MEDICATION - CREAMMicronized Calcium Citrate             5 to 40Salicylic Acid    .05 to 2Bentonite         Up to 10%Oleth 3-Phosphate Up to 5%Petrolatum        Up to 15%Carboner 934      Up to 3%Benzyl Alcohol    Up to 3%Water             RemainderACNE MEDICATION - OINTMENTMicronized Calcium Citrate             5 to 35%Salicylic Acid    .05 to 2%Polyethylene Glycol 4000             15 to 25%Cetyl Stearyl Glycol             Up to 5%Isopropyl Myristate             25 to 35%Benzyl Alcohol    1 to 3%Isopropyl or Ethylacohol             10 to 25%PRE-SHAVE LOTIONMicronized Calcium Citrate             3 to 20%Salicylic Acid    .05 to 2%Ethyl Alcohol     10 to 30%Water             RemainderAFTER-SHAVE LOTIONMicronized Calcium Citrate             3 to 20%Salicylic Acid    .05 to 2%Fragrance         10%Ethyl Alcohol     20%Water             RemainderSKIN MOISTURIZERMicronized Calcium Citrate             5 to 20%Salicylic Acid    .05 to 2%Ethyl Alcohol     20%Glycerine         10%Water             RemainderSUNSCREENMicronized Calcium Citrate             5 to 20%Salicylic Acid    .05 to 2%Oetyldimethylp-aminobenzoic-             15%acid (sunscreen)Ethyl Alcohol     20%Water             RemainderSOFT CORN REMOVERMicronized Calcium Citrate             10% to 40%Bentonite         5%Salicylic Acid    2 to 10%Ethyl Alcohol     30%Propylene Glycol  1 to 5%Water             RemainderHARD CORN REMOVERMicronized Calcium Citrate             10% to 40%Salicylic Acid    10 to 20%Ethyl Alcohol     30%Bentonite         5%Water             RemainderSOAPMicronized Calcium Citrate             2 TO 10%Salicylic Acid    .05 to 2%Soap Stock        30%Water             RemainderCOLD CREAMMicronized Calcium Citrate             3% to 20%Salicylic Acid    .05 to 2%Liquid Paraffin   5%Beeswax           5%Water             Remainder______________________________________ 
    
     The following specific examples display preferred product produced in accordance with the instant invention. 
     
         ______________________________________            Parts By Weight                      %______________________________________EXAMPLE 2Pre-Shave Condition for Topical AnalgesicComponent ACalcium Citrate    600         20.0Rhodigel 23        24          .8Collagen           30          1.0Germaben II        30          1.0Deionized Water    1573.2      52.4Component BEthanol SD 408     600         20.0Stearic Acid       22.8        .8Cetyl Alcohol      12          .4Isopropyl Myristate              30          1.0Solulan 98         30          1.0Salicylic Acid     45          1.5TOTAL A &amp; B        3000        100%EXAMPLE 3UNIVERSAL ACNE MASQUEComponent ACalcium Citrate    2240.0      28.0Bentonite          800.0       10.0Lo-Micron Pink     3.2         .0Component BCitric Acid        160.0       2.0Salicylic Acid     80.0        1.0Potassium Sorbate  6.4         .0Deionized Water    4310.4      54.0Component CSD Alcohol 40      400.0       5.0%TOTAL A,B &amp; C      8000.0      100%EXAMPLE 4Acne MedicationComponent ACalcium Citrate    400.0       10.0%Talc               60.0        1.5Kaolin             36.0        .9Titanium Dioxide   24.0        .6Methocel E-4M      4.8         .2Clark Pigments7076               5.6         .47055               4.0         .17133               2.4         .06Component BPropylene Glycol   120.0       3.0%Salicylic Acid     19.2        .5SD Alcohol 40      400.0       10.0Citric Acid        64.0        1.6Potassium Sorbate  3.2         .08Deionized Water    2856.8      71.4TOTAL COMPOSITION A &amp; B              4000.0      100.0%EXAMPLE 5ACNE MEDICATIONComponent ACalcium Citrate    2800.0      35.0Bentonite          400.0       5.0Lo-Micron Pink     3.2         .04Component BCitric Acid        192.0       2.4Salicylic Acid     120.0       1.5Potassium Sorbate  6.4         .08Propylene Glycol   160.0       20.0Deionized Water    3518.4      44.0Component CSD Alcohol 40      800.0       10.0TOTAL A, B &amp; C     8000.0      100.0%EXAMPLE 6SUNSCREENComponent AMicronized Calcium Citrate              12.5Rodigel 23 (Xanthan Gum Thick)              2.0Aloe Gel           25.0Potassium Sorbate  0.5Tetraethylamine (TEA)              1.25Water              176.25Component BEthanol            25.0Stearic Acid       5.0Catyl Alcohol      2.5Escalol 507        12.5(2-ethylhexyl salicylate)Total A &amp; B        262.50EXAMPLE 7NON-OILY MOISTURIZERComponent A:Micronizd Calcium Citrate              12.5Rhodigel 23        2.0Aloe Gel           50.0Tea                0.25Collagen           5.0Potassium Sorbate  0.5Deionized Water    134.5Component BEthanol            37.5Stearic Acid       2.0Cetyl Alcohol      1.0Dow 225            2.5Isopropyl Myristate              2.5Vitamin E          0.2Total A &amp; B        250.45______________________________________