that there is frequently free urine ( e. g. not absorbed by the absorbent article) and feces present adjacent to the wearer’s skin surface. In such a situation, one must rely on the ability of skin to maintain a free hydrogen ion concentration that effectively counteracts basic ions present in such bodily exudates. A limitation of this approach, therefore, is that in order to be effective, the capacity of the skin to resist changes in pH due to free urine and feces must be increased by the application of pH control agents before the skin actually comes into contact with the feces, ideally without disturbing the skin’s own homeostatic pH balance. 

[0007] Diapers impregnated with skin lotions comprising a buffer system are also known. For example, U.S. Pat. No. 5,525,346, issued to Hartung, et al. on Jun. 11, 1996 describes oil-in-water emulsions comprising a non-ionic emulsifier, a dimethicone, sodium citrate, citric acid, aloe vera, preservatives, and water. The patent further describes diapers where at least the portion of the diaper that contacts a wearer’s genitals and buttocks is impregnated with the oil-in-water emulsion. While such diapers may provide a skin care benefit, impregnating the diaper with such an emulsion can substantially interfere with the functionality of the diaper. For example, the portion of a diaper contacting a wearer’s genitals and buttocks is also the portion of the diaper that primarily receives bodily exudates, particularly urine. If this receiving area is impregnated with an emulsion as is described in U.S. Pat. No. 5,525,346, the absorptive properties thereof will be substantially compromised leading to an increased risk of leakage. Further, given the aqueous continuous phase of the skin lotion described in U.S. Pat. No. 5,525,346, the absorbent elements of the diaper may draw the aqueous phase away from the surface reducing any skin care benefit provided by the lotion. 

[0008] Thus, there is a continuing need to counteract the effects of ammonia and fecal enzymes on the skin of those wearing absorbent articles. There is a further need to provide improved absorbent articles that help maintain the pH of a wearer’s skin in its natural acidic state more specifically, between about 4.0 and about 6.0. 

[0009] The Applicants have discovered that it is possible to help maintain an acidic skin pH by the use of proton donating actives, such as buffer agents or acidic ammonia› neutralizing agents that transfer from an absorbent article to a wearer’s skin. Particularly preferred materials are proton donating actives that are effective in reducing the ability of fecal enzymes to decompose urinary urea into ammonia in addition to neutralizing any ammonia that may be present adjacent to a wearer’s skin. A particularly preferred means of delivering such ingredients is to incorporate them into a skin care composition that transfers from the absorbent article to a wearer’s skin carrying such proton donating actives to the surface of a wearer’s skin. 

## BRIEF DESCRIPTION OF THE DRAWINGS 

[0010] While the specification concludes with claims par› ticularly pointing out and distinctly claiming the present invention, it is believed that the present invention will be better understood from the following description in conjunc› tion with the following drawings, in which like reference numbers identity identical elements and wherein: 

## SUMMARY OF THE INVENTION 

[0011] FIG. 1 is a plan view of an absorbent article of the present invention in the form of a diaper. 

[0012] FIG. 2a is a side view showing placement of the skin analog used in the lotion transfer test. 

[0013] FIG. 2b is a plan view showing placement of the skin analog used in the lotion transfer test. 

[0014] I. Definitions 

[0015] As used herein, the term "comprising" means that the various components, ingredients, or steps can be con› jointly employed in practicing the present invention. Accordingly, the term "comprising" encompasses the more restrictive terms "consisting essentially of’ and "consisting of’. 

[0016] As used herein a "proton donating active" is a substance or mixture of substances, that, when the substance or mixture of substances is incorporated into a skin care composition and applied to a subject’s skin as is described in the Skin pH Reduction Test in the TEST METHODS section below, causes a decrease in skin pH. 

[0017] As used herein, "an absorbent article comprising a proton donating active" means any absorbent article, such as those described below, typically having a liquid impervious backsheet, a liquid pervious topsheet, and an absorbent core positioned between the topsheet and the backsheet, wherein the proton donating active is positioned within or on the topsheet, and/or within or on the absorbent core, and/or within or on the backsheet, and/or within or on any other portion of the absorbent article, including cuffs, side panels, fasteners, and the like. 

[0018] As used herein, the term "skin care composition comprising a proton donating active" refers to any compo› sition employed to transfer a minimum effective amount of the proton donating active from an absorbent article to a wearer’s skin to provide a therapeutic and/or protective skin benefit for the treatment or prevention of skin conditions, such as diaper dermatitis. Representative materials are dis› cussed in detail below. 

[0019] As used herein, the term "wearer-contacting sur› face" of an absorbent article is one or more surfaces of any article components that may contact the wearer’s body at some time during the wear period. Body contacting surfaces include, but are not limited to, portions of the topsheet, leg cuffs, waist region, side panels, and the like, which may contact a wearer during use. 

[0020] Other terms are defined herein where initially dis› cussed. 

[0021] With respect to proton donating active (s) and/or a skin care composition (s), all percentages, ratios and pro› portions used herein are by weight unless otherwise speci› fied. 

[0022] II. Absorbent Articles 

[0023] As used herein, the term "absorbent article" refers to a device which absorbs and retains body exudates. The term "disposable" is used herein to describe absorbent articles which are not intended to be laundered or otherwise 

## DETAILED DESCRIPTION OF THE INVENTION 

