Patent ID: 7323161

Claim:
A patch for tooth whitening, comprising a tooth-adhering layer ( 1 ) containing erodible polymer complexes formed by hydrogen bonding of a first polymer with a carboxyl group (—COOH) and a second polymer with a carbonyl group (—C=O) or ether group (—O—) and a tooth whitening agent, wherein the first polymer comprises from 1% to 10% of the total dry weight of the tooth-adhering layer, and the second polymer comprises from 40% to 80% of the total dry weight of the tooth-adhering layer; and wherein the first polymer with the carboxyl group is a (meth)acrylic acid copolymer, and the second polymer with the carbonyl group or ether group is polyvinylpyrrolidone; and an erosion rate-controlling layer ( 2 ) containing a mixture of a hydrophilic polymer and a film-forming polymer, wherein the hydrophilic polymer ranges from 10% to 60% of the total dry weight of the erosion rate-controlling layer and the film-forming polymer ranges from 5% to 65% of the total dry weight of the erosion rate-control layer; and wherein the hydrophilic polymer is hydroxypropyl cellulose and the film-forming polymer is a (meth)acrylic acid copolymer.