two separate compositions , one containing an antibiotic and one containing benzoyl peroxide are packaged within and dispensed from a common dispenser . more particularly , a dual dispenser contains i ) a first composition that is substantially anhydrous and includes a polar solvent , an antibiotic and a thickening agent selected from the group consisting of acrylic acid polymers and polyacrylamides ; and ii ) a second composition containing benzoyl peroxide or , alternatively , a retinoid . by packaging these two anti - acne active ingredients in this manner , long shelflife and convenient dispensing and application are provided .