A dispensing device includes a container having a wall that defines an opening into an interior, a first layer of carrier disposed in the interior distal from the opening, and a second layer of carrier disposed between the first layer and the opening, wherein the first layer of carrier isolates the second layer of carrier from the opening. The first layer of carrier has a first characteristic of an active ingredient, and the second layer of carrier has a second characteristic of active ingredient, wherein the first characteristic is different from the second characteristic. A barrier is disposed between the first layer and the second layer to retard or prevent diffusion of the active ingredient of the second layer into the first layer.