Tissue thickness compensator comprising at least one medicament

A stapling assembly for use with a stapler, said stapling assembly comprising:

• an anvil comprising a plurality of forming surfaces;
• a fastener cartridge comprising a plurality of fasteners stored therein, wherein said fasteners are formable against said forming surfaces;
• a tissue thickness compensator attached to said anvil, wherein said tissue thickness compensator comprises:
• a body portion comprising a porous material;
• and
• a plurality of cavities defined in said body portion, wherein said cavities are aligned with said forming surfaces such that said fasteners are configured to at least one of puncture said cavities when said fasteners are ejected from said fastener cartridge or capture said cavities and compress said cavities within said tissue thickness compensator when said fasteners are ejected from said fastener cartridge and formed by said forming surfaces;
• and
• at least one medicament positioned within each said cavity prior to firing the stapler, wherein said medicament is different than said porous material,
• wherein said plurality of cavities comprises a plurality of bubbles,
• wherein said tissue thickness compensator comprises a first layer and a second layer, and wherein said bubbles are defined between said first layer and said second layer.