Hydrogel compositions demonstrating phase separation on contact with aqueous media

摘要

A composition is provided, wherein the composition comprises a water-swellable, water-insoluble polymer or a water-soluble polymer, a blend of a hydrophilic polymer and a complementary oligomer capable of hydrogen bonding to the hydrophilic polymer. The composition also includes a second water-swellable, water-insoluble polymer that provides for a phase separating film forming composition. Active ingredients, such as a whitening agent, may be included. The composition finds utility as an oral dressing, for example, a tooth whitening composition that is applied to the teeth in need of whitening, and removed when the degree of whitening has been achieved. In certain embodiments, the composition is translucent. Methods for preparing and using the compositions are also disclosed.

主权项

1. A phase separating, film-forming composition comprising:
a water-swellable acrylate-based polymer, said polymer being insoluble in water at a pH less than about 5.5; a blend of a poly(N-vinyl lactam) homopolymer and a complementary oligomer capable of hydrogen bonding to the poly(N-vinyl lactam) homopolymer; a water-swellable cellulose ester polymer, that is insoluble in water at all pH values; and an optional active agent, wherein upon exposure to an aqueous environment at a pH of from about 6-8, the composition undergoes a phase separation wherein the water-swellable cellulose ester polymer forms a film over the remainder of the composition comprising the water-swellable acrylate-based polymer or, the blend of the poly(N-vinyl lactam) homopolymer and complementary oligomer and optional active agent; and wherein the weight ratio of the acrylate-based polymer to the cellulose ester polymer is within a range of about 1.5:1 to 2:1.