Oct. 10, 2002  7  US 2002/0147433 Al  a-chlorosorbic acid, angelic acid, cinnamic acid, p-chloro› cinnamic acid, ~-stearylacrylic acid, itaconic acid, citraconic  acid, mesaconic acid, glutaconic acid, aconitic acid, maleic  acid, fumaric acid, tricarboxyethylene, and maleic anhy› dride, copolymers of unsaturated monomeric acids with  suitable co-monomers, and partially neutralized salts of such  polymers; acidic cellulose derivatives, such as carboxym› ethyl cellulose at least partially wherein the cellulose deriva› tives are at least partially protonated, cellulose phosphate,  and oxidized cellulose; and cation exchange resins wherein  the cation exchange resin is at least partially protonated.  [0059]  Exemplary inorganic acid salts include alkali metal  monohydrogen phosphates, blends of alkali metal monohy› drogen and dihydrogen phosphate salts, alkali metal mono› hydrogen pyrophosphate salts, and blends of alkali metal  monohydrogen and dihydrogen pyrophosphate salts.  [0060]  In an alternative embodiment, materials which can  decompose in the environment adjacent to a wearer’s skin  into a proton donating active are also suitable for the  purposes of the present invention. For example, esterase  enzymes in feces (e.g. fecal lipases) can hydrolyze certain  esters to provide a proton donating active. Suitable proton  donating actives of this type have the formula:  [0061]  wherein  R$_{1}$ ,  R$_{2 }$ and  R$_{3 }$ are independently hydrogen,  an alkyl group, an alkenyl group, or a hydroxyalkyl group  with from 1 to 4 carbon atoms.  An exemplary ester of this  type is triacetin. As can be seen in Example 6, such mate› rials, in the presence of bodily exudates, are effective in  providing a pH reduction.  [0062]  In order that the proton donating active be effective  in helping maintain skin at an acidic pH the proton donating  active should be provided at a level of at least 0.01 % of the  skin care composition; typically at least about 0.5%; pref› erably at least about 3%. Such suitable proton donating  actives may be used as a component of the skin care  compositions of the present invention at a level of between  about 0.01 % and about 40%, depending on the specific  proton donating active chosen. Preferably, the proton donat› ing actives are used at a level of between about 0.5% and  about 20% of the skin care composition of the present  invention. In particularly preferred embodiments of the  present invention, the proton donating actives are provided  at a level of between about 3% and about 7%.  [0063]  IV. Delivery Systems  [0064]  A  proton donating active delivery system in an  absorbent article preferably contains a minimum effective  concentration of a proton donating active(s) and does not  itself interfere with the normal function of the vanous  structures of the article ( e.g., the absorbency of the core, the  liquid perviousness of the top sheet, and the like). In a  preferred embodiment, described in greater detail below, the  proton donating active(s) is positioned in proximity to the  wearer’s skin in a clean dry article, such as on or near a body  contacting surface, from where at least a portion of the  proton donating active(s) may be delivered to the wearer’s  skin during normal use of the article, preferably before a  bowel movement occurs, for availability to act at the skin/  feces interface after a bowel movement. In a more preferred  embodiment, the. proton donating active(s) is (are) a com› ponent of a skin care composition containing various emol› lients and immobilizing agents, as described further below,  that is delivered directly from a wearer-contacting surface to  the wearer’s skin to perform a barrier function to high  pH  exudates, as well as helping maintain the wearer’s skin at an  acidic pH. Most preferably, repeated normal use of articles  having delivery systems that deliver proton donating actives  directly to the skin provides an accumulation of the proton  donating active for more effective prevention of inflamma› tion of the skin due to contact with urine and feces.  [0065]  Thus, proton donating actives, or compositions  containing them, may be incorporated into absorbent articles  in any delivery system known to those skilled in the art that  facilitates contact of a proton donating active with a wear› er’s skin to inhibit pH increases thereon. The delivery  system may be a component of any portion or portions of the  absorbent article including, but not limited to, the topsheet,  the absorbent core, the backsheet, other secondary structures  such as additional sheets, specialized structures to contain  bowel movements (e.g., bowel movement "pockets"), and  the like, and any cuffs, side panels, fasteners and the like that  may also be a component of the article, whether or not the  portion of the article is a wearer-contacting surface. Such  delivery systems include those which deliver the proton  donating active in dispersed form as a component of another  composition, in solution in a substantially anhydrous com› position, and in an aqueous vehicle as a part of a substan› tially oleaginous composition (e.g. as a water-in-oil emul› sion). Exemplary delivery systems include, but are not  limited to, those described below.  [0066]  The delivery system may provide the proton donat› ing active in powder, flake or particulate form. The delivery  system may include pressure-rupturable or dissolvable  microcapsules or "bubbles" containing the proton donating  active or a proton donating active-containing composition.  Further, the delivery system may include the ingredients or  an ingredient-containing composition in any other form that  is activated ( e.g. by hydrolysis of a precursor material) in the  presence of bodily exudates. A particularly suitable delivery  system for use with the proton donating actives of the  present invention is one having a continuous phase com› prising substantially oleaginous materials. As used herein a  delivery system comprises "substantially oleaginous mate› rials" if at least about fifty percent of the continuous phase  thereof comprises oleaginous emollients, immobilizing  agents, and the like as are discussed individually below.  Dispersions or solutions of solid proton donating actives in  substantially  anhydrous compositions and water-in-oil  emulsions, wherein the proton donating actives are a com› ponent in the disperse aqueous phase thereof, are specifi› cally contemplated as having a continuous phase comprising  substantially oleaginous materials. As used herein, a com- H  0  I  II  H-c-o-c-R 1  I  TI  H-C-O-C-R 2  I  TI  H-c-o-c-R 3  I  H 