Abstract:
An oral care implement includes a reservoir containing at least one active agent. The implement has an activator for activating a delivery device which delivers a predetermined amount of an active agent to one or more outlets. A wide variety of types of active agents can be administered at appropriate and accurate doses for therapeutic, hygienic, and/or other benefits.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority to U.S. Patent Application No. 60/698,594, filed Jul. 12, 2005 in which the contents are incorporated by reference herein. 
    
    
     FIELD OF THE INVENTION 
     The present invention is directed to an oral care implement having a reservoir for dispensing an active agent. 
     BACKGROUND OF THE INVENTION 
     Many currently available toothpastes contain auxiliary agents for tooth whitening or other hygienic purposes in addition to tooth cleaning. Although many types of agents can be effectively incorporated into toothpastes, the ability to incorporate auxiliary components into toothpastes is limited by such factors as the compatibility of the components with the toothpaste and possible deleterious effects the components and the toothpaste may have on each other. For example, a reactive component may become neutralized prior to use, or may adversely affect the shelf life, viscosity, taste, or other properties of the toothpaste. 
     U.S. Pat. No. 6,135,126 to Joshi, incorporated herein by reference, discloses a toothbrush having an electrochemical cell for generating an oxidizing gas via an internal electrochemical process. During brushing, a user engages a switch to activate an internal electrochemical cell which generates the oxidizing agent, such as oxygen. The oxidizing gas is exhausted to the bristle portion of the brush for application to the user&#39;s oral cavity. Other gaseous products generated in the electrochemical cell, such as hydrogen, are directed away from the bristle portion of the brush. This arrangement has inherent drawbacks. 
     There remains a need for an improved oral care implement having the ability to deliver beneficial agents using an oral care implement without suffering from drawbacks and limitations known in the art. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to an oral care implement having a reservoir containing at least one active agent. 
     The oral care implement has a delivery device actuator, such as a switch, for activating a delivery device, such as a pump, which delivers a predetermined amount of a substance, such as an active agent, to one or more outlets, which can be located in the vicinity the tooth cleaning elements, e.g., bristles, and/or other portion(s) of the oral care implement. A wide variety of active agents can be administered at appropriate and accurate doses for therapeutic, hygienic, and/or other benefits, such as fresh breath, tooth whitening, reducing sensitivity of the teeth or producing sensations of heat, cool, or tingling. 
     The oral care implement advantageously can be manufactured at relatively low cost, is easy to use, and can deliver a predetermined quantity of an active agent upon a user activating a switch. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The objects, features, and advantages of the invention will be apparent from the following more detailed description of certain embodiments of the invention and as illustrated in the accompanying drawings in which: 
         FIG. 1  is a schematic illustration of a toothbrush according to one embodiment of the invention; and 
         FIG. 2  schematically illustrates a replaceable cartridge in accordance with another embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  schematically illustrates a toothbrush  1  having a handle  10  and a head  12  containing tooth cleaning elements, such as bristles  16  and/or elastomeric cleaning elements (not shown) or the like. A storage location, such as a reservoir  15 , is provided within the handle  10  for storing the active agent. The handle  10  or other exterior portion of the toothbrush  1  preferably contains a delivery device actuator or switch, such as a user-actuated button  22 , for activating a delivery device such as pump  18 . The pump  18  can be located before or after the reservoir  15 . Upon pressing the button  22 , the pump  18  causes a predetermined quantity of a medium preferably containing an active agent to be delivered from the reservoir  15  through a channel  19  leading to a plurality of outlets  20 . 
     As shown in  FIG. 1 , the outlets  20  may be located on the surface of the head  12  between or in the vicinity of the bristles  16 . Alternatively, the outlets  20  may be located on other portions of the head  12 , handle  10 , or elsewhere on the toothbrush  1 . Alternatively, the active agent may be delivered through the bristles  16 , such as if the bristles comprised hollow lumens or the like. In this arrangement, the tip of the bristles made have at least one aperture for releasing the active agent. Alternatively, the active agent can also be delivered simultaneously through outlets  20  located at different portions of the toothbrush  1 , for example to aid in the application of the active agent to different areas of the mouth. Although a plurality of outlets  20  is illustrated, it is contemplated that a single outlet could be used. 
     The switch for activating the pump  18  may be a button  22 , as illustrated in  FIG. 1 , or may be another type of switch such as a user-activated toggle switch or rotating dial. Depressing the button  22  preferably activates a timing circuit which causes the pump  18  to operate for an interval needed to pump a predetermined amount of the medium containing the active agent from the reservoir  15  and through the outlets  20 . The pump is connected to a power source or has a power source, such as a battery (not shown). The timing circuit causes the pump  18  to operate for an interval of time which either may be preset or may be adjustable, e.g., by a user-activated rotating dial, which may vary depending on the active agent and the desired delivery regimen. While an external switch  22  has been described, it will be appreciated that a user-operated, internal switch that activates the delivery device upon the mechanical action of brushing, is also contemplated. 
     The medium containing the active agent can be incorporated into a sealed reservoir  15  during manufacture of the toothbrush  1 , in which case the toothbrush  1  can be disposed of after the supply of the active agent is exhausted. Alternatively, the reservoir  15  can be refillable through an inlet (not shown), or can be replaceable, e.g., by inserting a replaceable cartridge into a recess in the toothbrush or toothbrush handle  10 .  FIG. 2  schematically illustrates an example of a replaceable cartridge  30 . The cartridge can have a sharpened element  35  which penetrates a membrane in the recess of the toothbrush to permit the medium to flow from the cartridge  30  into the channel  19 . The cartridge  30  can be spring-loaded to stay in place after insertion into the recess, and can have a seal to prevent unwanted leakage of the active agent. The cartridge  30  can be disposable or refillable. Other methods of providing a refillable and/or replaceable cartridge or the like are contemplated. 
     Optionally, a user-activated switch, such as a dial (not shown), can have multiple settings for selecting one of several active agents. For example, the dial can have a first setting for oxidizer/whitener treatment, a second setting for breath freshener treatment, and a third setting for antimicrobial treatment. The dial setting instructs the timing circuit to activate the pump  18  for a time interval appropriate for the selected active agent. 
     In one embodiment, a kit comprises a toothbrush and at least one cartridge containing an active agent. A user may select among multiple cartridges for a desired treatment. If the active agents have different intervals of application, the toothbrush can be provided with a dial, as previously described, to enable the user to select the appropriate setting. Similarly, a single cartridge can come pre-loaded with multiple active agents that can be selectively accessed and delivered by a switch or the like. The kit can also include a dentifrice if desired. 
     The predetermined amount can be suitably selected to deliver an accurate dose of the active for its intended purpose. The amount can be controlled by controlling the duration the pump  18  operates after the button  22  is pressed. The duration of dispensation will depend on the desired dose and the flowrate of the medium, and typically ranges from about 1 second to 5 minutes, often from about 5 seconds to about 2 minutes, and preferably ranges from about 10 seconds to 30 seconds. The timing of the dispensing action can be either right after the button  22  is pressed, or at a delay programmed as desired. 
     Any suitable pump can be used for delivering the medium from the reservoir  15  to the outlets  20 . Suitable devices are commercially available, such as the gas-generating cell or microcell technology available from Microlin Technology/Ceramatec Inc. Reference also is made to U.S. Pat. Nos. 6,135,126, 6,575,961, 6,045,055, 5,427,870, and 5,567,287, and published application U.S. 2005/0023371 A1, the disclosures of which are hereby incorporated by reference as alternative pump arrangements useable in the toothbrush. The pump may deliver the medium through a variety of different actions that are mechanical, electrical, chemical or a combination thereof, depending on the pump structure. For example, the gas-generating cell available from Microlin Technology employs a piston-cylinder type of arrangement. 
     Advantageously, the active agent itself can be contained in the reservoir  15 . In other words, it is not necessary to generate the active agent internally or in situ. This simplifies the construction of the toothbrush and avoids the need to handle any byproducts associated with the synthesis of the active agent. Alternatively, an agent in one reservoir can be delivered via a delivery device to another reservoir where it is “activated,” where it is then delivered via another delivery device to the one or more outlets. This type of delivery system, employing multiple connections that are direct or indirect, is also contemplated within the scope of the present invention. 
     In  FIG. 1 , a toothbrush  1  is shown schematically having a head  12 , bristles  16 , and a handle  10 . It should be understood that any bristle configuration and any handle configuration can be used, and the present invention should not be regarded as being limited to any particular configuration. The outlet(s)  20  preferably are located in the bristle region on the bristle side of the head of the toothbrush, for example between or interspersed with bristles  16 . Alternatively, the outlet(s)  20  can be located on the side of the head opposite the bristles, or on the side edges of the head, or on a combination of sides as desired. Alternatively, the outlet(s)  20  can be located adjacent the head or in the region of the head, but not actually on the head. 
     The toothbrush  1  can be used by applying toothpaste to the bristles  16  and brushing the teeth in a conventional manner. A predetermined amount of the active agent is administered by activating the switch, e.g., depressing button  22 , to activate the pump  18 , which causes the medium containing the active agent to be delivered though the outlets  20 . The switch instructs the timing circuit to activate the pump  18  for a predetermined time, which in turn dispenses the active agent in a predetermined dose through the outlets  20 . The active agent can be then applied to the teeth of a user using bristles  16  via the outer surface of the bristles  16 . Nevertheless, in another arrangement, the active agent can be applied teeth via a lumen within the bristle  16 , instead of outlet  20 . The active agent can be administered before, during, or after brushing. 
     Non-limiting examples of active agents which can be used include antibacterial agents, such as chlorhexidine, cetyl pyridininum chloride, triclosan, zinc salts, and magnolia extract; anti-attachment agents, such as ethyl lauroyl arginine HCl; oxidative or whitening agents, such as hydrogen peroxide, urea peroxide, sodium percarbonate, and PVP-H 2 O 2 ; anti-cavity agents, such as sodium fluoride, sodium monofluorophosphate, stannous fluoride; supercharged fluoride delivery ingredients (such as dicalcium phosphate dihydrate and others disclosed in U.S. Pat. No. 5,785,956); tooth sensitivity ingredients, such as KNO 3 , stannous fluoride, sodium silicate, and bioactive glass (such as those disclosed in U.S. Pat. No. 6,338,751); gum health actives, including those which reduce inflammation pathways and/or interfere in bacterial processes which produce inflammatory stimuli, such as Univestin (Unigen Pharma), bachalin, polyphenols, ethyl pyruvate, green tea extracts, rosemary extracts and other herbal extracts, and guanidinoethyl disulfide; nutritional type ingredients, such as vitamins, minerals, amino acids, vitamin E, and folic acid; tartar control or anti-stain ingredients, including phosphate salts, polyvinylphosphonic acid, PVM/MA copolymer; enzymes, such as those used for plaque disruption; sensate ingredients, such as those providing cooling (such as menthol), tingle, or heat sensations (such as capsaicin or capsicum oil); flavors and flavor ingredients; colorants or other aesthetic agents; and combinations thereof Examples of flavors and flavor ingredients include essential oils, menthol, carvone, and anethole, and various flavoring aldehydes, esters, and alcohols. Examples of essential oils include oils of spearmint, peppermint, wintergreen, sassafras, clove, sage, eucalyptus, marjoram, cinnamon, lemon, lime, grapefruit, and orange. 
     The active agent and/or its medium can be selected to complement the toothpaste formula, such as by coordinating flavors, colors, aesthetics, or active ingredients. A flavor can be administered to create a gradual flavor change during brushing, which presently is not possible using toothpaste alone. The flavor changes described here along with other changes in sensation can also be used as a signal for indicating that an effective brushing routine is complete. A colorant can be added to create a color change during use. Flavor and/or color can also be used to signal another benefit, such as tooth whitening or anti-bacterial action. 
     The active agent may be compatible with toothpaste, or may be unstable and/or reactive with typical toothpaste ingredients. Non-limiting examples of components which tend to be unstable and/or reactive with typical toothpaste ingredients include hydrogen peroxide, sodium fluoride (reacts with calcium or zinc salts), various calcium salts (reacts with sodium fluoride), and cationic ingredients, such as cetyl pyridinium chloride, chlorhexidiene, and ethyl lauroyl arginine HCl (react with SLS, other anionic ingredients, and many silica abrasives). The active agent also may be a tooth cleaning agent to boost the overall efficacy of brushing. Such tooth cleaning agents may or may not be compatible with the toothpaste ingredients. 
     The active agent can be provided in any suitable vehicle, such as in an aqueous solution or a non-aqueous solution or an oil or in the form of gel or paste or an emulsion or a multiple emulsion or a liquid crystal gel. The vehicle can have a variety of different visual aesthetics including clear solution or gel or opaque solution or gel. Non-limiting examples of vehicles include water, monohydric alcohols such as ethanol, poly(ethylene oxides) such as polyethylene glycols such as PEG 2M, 5M, 7M, 14M, 23M, 45M, and 90M available from Union Carbide, carboxymethylene polymers such as Carbopol® 934 and 974 available from B. F. Goodrich, and combinations thereof. The selection of a suitable vehicle will be apparent to persons skilled in the art depending on such factors as the properties of the active agent and the desired properties of the medium, such as viscosity. Examples of tooth whitening compositions are described in U.S. Pat. Nos. 6,770,266 and 6,669,930, the disclosures of which are hereby incorporated by reference. 
     The predetermined quantity of the medium dispensed may vary over a wide range depending on such factors as the identity of the active agent and its concentration in the medium. The quantity dispensed usually ranges from about 1 to about 100 μL per use, more usually from about 5 to about 50 μL. For example, the pump  18  can be configured to deliver 10 μL of 20% cetylpyridinium chloride gel over a period of 30 seconds, e.g., for application during the first 30 seconds of brushing the teeth. An advantage of this delivery is that ingredients incompatible with the toothpaste are exposed to the toothpaste as little as possible. 
     The reservoir can contain a quantity of the active agent medium intended for a single use or a small number of uses, or may facilitate repeated use over an extended period of time, e.g., up to several months or several years (if used with a toothbrush having a replaceable head for example). The size of the reservoir can be selected to be compatible with the desired overall dimensions of the toothbrush  1  as well as such factors as the stability of the active agent and the quantity of medium administered during each application. 
     The supply of active agent in the reservoir  15  preferably is free or substantially free of components which are incompatible with the active agent and/or the medium containing the active agent, such as incompatible toothpaste components as previously identified. In the preferred practice of the invention, the reservoir  15  is free or substantially free of toothpaste, as toothpaste is separately applied to the bristles  16  by the user. Alternatively as noted above, an active agent may be originally retained in one reservoir and then transferred to another reservoir where it is activated just prior to delivery, which may be useful in certain conditions or circumstances. 
     The toothbrush  1  can be equipped with a light source, such as an ultraviolet (UV) or infrared (IR) light. The light source can be used to enhance tooth cleaning or whitening by itself and/or by activating the active agent and/or ingredients in the toothpaste. The toothbrush  1  can have a secondary switch (not shown) for activating the light source. An example of a toothbrush having a UV light source for activating a photoactivatable material for tooth cleaning is described in U.S. Pat. No. 6,343,400 to Massholder et al. The back of the toothbrush  1  can be equipped with a special surface for polishing teeth with (silica) toothpaste. Non-limiting examples of such a surface include rubber, elastomer, woven fabric or wool. 
     The toothbrush  1  optionally can be provided with compartments and/or access panels for access to the various components, such as the power source and reservoir. The power source can be, for example, a replaceable or rechargeable battery as well known. 
     The following examples are provided for illustrative purposes only and should not be construed as limiting the scope of the present invention. 
     Example 1 
     Table I illustrates a cetylpyridinium chloride concentrate that is dispensed from a toothbrush reservoir during brushing as an antibacterial agent. 
     
       
         
               
               
               
             
           
               
                   
                 TABLE I 
               
               
                   
                   
               
               
                   
                 Ingredient 
                 Wt % 
               
               
                   
                   
               
             
             
               
                   
                 Carbopol 974P 
                 1–2 
               
               
                   
                 PEG 600 
                 10 
               
               
                   
                 FD&amp;C blue #1(1% 
                 0.5 
               
               
                   
                 Cetylpyridinium chloride 
                 20 
               
               
                   
                 Water 
                 Q.S. 
               
               
                   
                   
               
             
          
         
       
     
     Example 2 
     Table II shows a hydrogen peroxide solution that is dispensed from a toothbrush reservoir during brushing as a whitening booster. 
     
       
         
               
               
               
             
           
               
                   
                 TABLE II 
               
               
                   
                   
               
               
                   
                 Ingredient 
                 Wt % 
               
               
                   
                   
               
             
             
               
                   
                 Carbopol 974P 
                 1–2 
               
               
                   
                 Hydrogen peroxide 
                 30 
               
               
                   
                 Water 
                 Q.S. 
               
               
                   
                   
               
             
          
         
       
     
     Example 3 
     Table III illustrates a hydrogen peroxide gel which that is dispensed from a toothbrush reservoir during brushing as a whitening liquid. The gel also can be applied post-brushing for tooth whitening. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                   
                 TABLE III 
               
               
                   
                   
               
               
                   
                 Ingredient 
                 Wt % 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Water 
                 10.07 
               
               
                   
                 Carbopol 974 
                 1.00 
               
               
                   
                 95% Ethyl alcohol 
                 34.8 
               
               
                   
                 Glycerin 
                 5.00 
               
               
                   
                 PEG 600 
                 10.00 
               
               
                   
                 PEG 2M 
                 14.00 
               
               
                   
                 Hydrogen peroxide 
                 25.00 
               
               
                   
                 85% Phosphoric acid 
                 0.05 
               
               
                   
                 Monobasic sodium phosphate 
                 0.05 
               
               
                   
                 Total 
                 100.00 
               
               
                   
                   
               
             
          
         
       
     
     Example 4 
     Table IV shows a phosphoric acid solution that is dispensed from a toothbrush reservoir during brushing as a whitening liquid. The solution has a pH of about 4.0. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                   
                 TABLE IV 
               
               
                   
                   
               
               
                   
                 Ingredient 
                 Wt % 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Purified water 
                 25.1 
               
               
                   
                 Carbopol 974 
                 1.00 
               
               
                   
                 95% Ethyl alcohol 
                 34.8 
               
               
                   
                 Glycerin 
                 5.00 
               
               
                   
                 PEG 2M 
                 15.00 
               
               
                   
                 Urea peroxide 
                 18.00 
               
               
                   
                 85% Phosphoric acid 
                 0.10 
               
               
                   
                 Monobasic sodium phosphate 
                 1.0 
               
               
                   
                 Total 
                 100.00 
               
               
                   
                   
               
             
          
         
       
     
     Example 5 
     Table V illustrates another hydrogen peroxide solution that is dispensed from a toothbrush reservoir during brushing as a whitening booster. The composition alternatively can be applied to the teeth after brushing as a whitening agent. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                   
                 TABLE V 
               
               
                   
                   
               
               
                   
                 Ingredient 
                 Wt % 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Carbopol 974P 
                 1 
               
               
                   
                 95% ethyl alcohol 
                 34.8 
               
               
                   
                 Glycerin 
                 5 
               
               
                   
                 PEG 600 
                 10 
               
               
                   
                 PEG 2M 
                 14 
               
               
                   
                 85% phosphoric acid 
                 0.05 
               
               
                   
                 Monobasic sodium phosphate 
                 0.05 
               
               
                   
                 Hydrogen peroxide 
                 25 
               
               
                   
                 Water 
                 Q.S. 
               
               
                   
                   
               
             
          
         
       
     
     Example 6 
     Alternative liquid whitening gels are prepared by modifying the base formula of Example 5 by adding either (1) 2 to 5 wt % polyethylene (PE) powder having an average particle size of 6 to 8 microns; (2) 1 to 5 wt % polytetrafluoroethylene (PTFE) powder having particle size of 5 to 6 microns; (3) 0.8 to 2.5 wt % polypropylene (PP) powder having a particle size of 4 to 50 microns; (4) 2 to 5 wt % PE powder and 0.11 to 0.4 wt % titanium dioxide powder having a particle size of 10 to 45 microns. Examples of gels having the polymer and/or inorganic titanium powders incorporated in the base formula are shown in Tables VI and VII. 
     
       
         
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                   
                 TABLE VI 
               
               
                   
                   
               
               
                   
                   
                   
                   
                   
                   
                   
                 G 
               
               
                   
                 A 
                 B 
                 C 
                 D 
                 E 
                 F 
                 (wt 
               
               
                   
                 (wt %) 
                 (wt %) 
                 (wt %) 
                 (wt %) 
                 (wt %) 
                 (wt %) 
                 %) 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 Base 
                 99.0 
                 98.0 
                 95.0 
                 98.0 
                 95.0 
                 99.2 
                 97.5 
               
               
                 Formula 
               
               
                 +PE 
                 — 
                 — 
                 — 
                 2.0 
                 5.0 
                 — 
                 — 
               
               
                 +PTFE 
                 1.00 
                 2.0 
                 5.0 
                 — 
                 — 
                 — 
                 — 
               
               
                 +PP 
                 — 
                 — 
                 — 
                 — 
                 — 
                 0.8 
                 2.5 
               
               
                   
               
             
          
         
       
     
     
       
         
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                   
                 TABLE VII 
               
               
                   
                   
               
               
                   
                 GA 
                 H 
                 I 
                 J 
                 K 
                 L 
               
               
                   
                 (wt %) 
                 (wt %) 
                 (wt %) 
                 (wt %) 
                 (wt %) 
                 (wt %) 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 Base Formula 
                 99.5 
                 97.90 
                 97.80 
                 97.60 
                 94.90 
                 99.5 
               
               
                 +PE 
                 — 
                 2.00 
                 2.00 
                 2.00 
                 5.00 
                 — 
               
               
                 +TiO 2   
                 — 
                 0.10 
                 0.20 
                 0.40 
                 0.10 
                 0.5 
               
               
                 +TiO 2  coated 
                 0.5 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 mica 
               
               
                   
               
             
          
         
       
     
     Example 7 
     Table VIII shows another exemplary composition of a liquid whitening gel that is dispensed from a reservoir of a toothbrush during brushing as described herein. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                   
                 TABLE VIII 
               
               
                   
                   
               
               
                   
                 Liquid Gel Formula 
                 Wt % 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Carbomer 
                 1.00 
               
               
                   
                 PEG 600 
                 9.96 
               
               
                   
                 BHT 
                 0.03 
               
               
                   
                 Glycerin 
                 4.98 
               
               
                   
                 Water 
                 17.00 
               
               
                   
                 Ethyl alcohol 
                 34.67 
               
               
                   
                 PEG 2M 
                 13.95 
               
               
                   
                 H 2 O 2 (35%) 
                 17.93 
               
               
                   
                 Sodium Phosphate 
                 0.05 
               
               
                   
                 Phosphoric acid 
                 0.05 
               
               
                   
                 Titanium dioxide 
                 0.38 
               
               
                   
                   
               
             
          
         
       
     
     Example 8 
     Table IX example shows the composition of a breath protection gel that is dispensed from a toothbrush reservoir as described herein. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                   
                 TABLE IX 
               
               
                   
                   
               
               
                   
                 Ingredient 
                 Wt % 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Carbopol 974P 
                 1 
               
               
                   
                 PVM/MA copolymer 
                 10 
               
               
                   
                 Triclosan 
                 20 
               
               
                   
                 Ethyl alcohol 
                 40 
               
               
                   
                 Zinc gluconate 
                 20 
               
               
                   
                 Water 
                 Q.S.