clindamycin1%/tretinoin 0.025%

During each study visit, investigators/assessors evaluated acne severity of the participants' faces using the ISGA scale: 0=clear skin with no lesions (L); 1=almost clear, rare non-inflammatory L; 2=mild, some non-inflammatory L with no more than a few inflammatory L, no nodular L; 3=moderate, many non-inflammatory L, may have some inflammatory L, but no more than 1 small nodular L; 4=severe, many non-inflammatory and inflammatory L, but no more than a few nodular L; 5=very severe, many non-inflammatory and inflammatory L, and more than a few nodular L.

During each study visit, trained study personnel at every investigational center assessed the inflammatory (pustules \[small inflamed elevation of the skin that is filled with pus\], papules \[solid elevation of skin with no visible fluid\], nodules \[larger than papules with significant depth\]) lesion counts for each participant. Each type of lesion was counted separately, and counts were taken from the face (including forehead, nose, cheeks, and chin). Missing values were imputed using the last observation carried forward (LOCF) method.

During each study visit, trained study personnel at every investigational center assessed the non-inflammatory (open comedones \[blackheads\] and closed comedones \[whiteheads\]) lesion counts for each participant. Each type of lesion was counted separately, and counts were taken from the face (including forehead, nose, cheeks, and chin).

During each study visit, trained study personnel at every investigational center assessed the inflammatory (pustules, papules, nodules) and non-inflammatory (open and closed comedones) lesion counts for each participant. Each type of lesion was counted separately; the lesion counts were taken from the face (including forehead, nose, cheeks, and chin). Total lesion counts were calculated as the sum of the inflammatory and non-inflammatory lesion counts.

Acne lesion counts (inflammatory \[papules, pustules, nodules\], non-inflammatory \[open and closed comedones\], and total) were performed on the face of participants. Change from baseline is defined as Week 12 values minus Baseline values. The total lesion count is the sum of the inflammatory and non-inflammatory lesion counts.

The ISGA is a static ("snap-shot") evaluation of acne severity performed by an investigator/assessor at every visit. The ISGA score is measured on a 6-point ordinal scale, where 0=Clear and 5=Very Severe. Change is calculated as the Week 12 value minus the Baseline value.

In cases where the patch area is larger than the irradiated area, only the irradiated areas will be scored unless reactions outside the irradiated area exhibit unusual responses. Scores represent the presence of clinically significant effects on at least 25% of the test site. Questionable, barely perceptible, or minimal reactions involving less than 25% of the test site will not be considered significant.