Structures and compositions increasing the stability of peroxide actives

A packaged tooth whitening product, comprising:

• a package;
• a substrate disposed within said package having a first section and a second section that is separable from said first section;
• a layer of a tooth whitening composition comprising a peroxide active disposed adjacent said substrate, wherein said layer has a thickness between about 0.05 mm and about 1 mm and wherein said layer has a first section disposed adjacent said first section of said substrate and a second section disposed adjacent said second section of said substrate;
• and
• wherein said first sections of said substrate and said tooth whitening composition can be applied to a user's teeth without said second sections of said substrate and said tooth whitening composition, and wherein the ratio of the exposed surface area of said layer to the volume of said layer is between about 0.05 mm−1 and about 0.15 mm−1.