Multi-layer patches for teeth whitening

摘要

The present invention relates to a dry type teeth whitening patch with a multi-layer structure of three or more layers. More particularly, in the dry type patch, a contact adhesive layer substantially free of peroxide comprises a hydrophilic glass polymer as a base polymer so that it provides substantial adhesive strength when hydrated by water, an active material reservoir layer comprises peroxide as a teeth whitening agent, and a backing layer which is impermeable to water. The dry type patch of the present invention has superior teeth whitening effect and excellent peroxide stability at a high temperature since the peroxide-containing layer is covered and protected by other layers.