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AssigneeBrown University Research Foundation
InventorsEdith Mathiowitz, Jules S. Jacob, Yong S. Jong, Donald E. Chickering III, Edwin E. Edwards
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Methods for inducing a thermoplastic polymer, which can be non-mesogenic, to exhibit liquid crystalline properties have been developed. The method includes the steps of (a) heating the polymer from an initial temperature below its glass transition temperature (Tg) to a temperature greater than its Tg and below its melting temperature (Tm); (b) exposing the polymer to a pressure greater than about 2 metric tons/in2, preferably between about 2 and 10 metric tons/in2, preferably for at least about one minute, while maintaining the temperature greater than its Tg; and (c) cooling the polymer below the Tg while maintaining the elevated pressure. Unlike many prior art transition processes which are reversible, this process provides a liquid crystal state that can be maintained for years at ambient conditions. In a preferred embodiment, the plastics are bioerodible thermoplastic polymers, such as polyanhydrides, some polyesters, polyamides, and polyaromatics. The liquid crystalline polymers can be used in the controlled release or retention of substances encapsulated in the polymers. The polymer can be in a variety of forms including films, film laminants, and microparticles. In a preferred embodiment, the LC polymers are used to encapsulate therapeutic, diagnostic, or prophylactic agents for use in medical or pharmaceutical applications.
A method for inducing a liquid crystalline state in a polymer comprising the steps of:
A composition comprising a non-mesogenic polymer which exhibits liquid crystalline properties at a temperature below the glass transition temperature of the polymer.
A method for release of an encapsulated agent comprising
An article for the release of an encapsulated agent comprising a polymer which exhibits liquid crystalline properties at a temperature below the glass transition temperature of the polymer, and the agent encapsulated in the polymer,
A monolithic composition for controlled delivery of an active agent comprising made using a process comprising
A barrier composition for use in packaging comprising
A packaging article comprising the barrier composition of 33.
Dependencies are inferred from the claim text.