Brown University

Yong S Jong

Edith Mathiowitz

Jules S Jacob

Donald E Chickering, Iii

Gerardo P Carino

Edwin E Edwards

A process is provided for making dry, micronized particles of an agent, such as a drug. The method includes (a) dissolving a macromolecular material, preferably a polymer, in an effective amount of a solvent, to form a solution; (b) dissolving or dispersing the agent in the solution to form a mixture; (c) freezing the mixture; and (d) drying by vacuum the mixture to form solid particles of the agent dispersed in solid macromolecular material. The micronization in this process occurs directly in a macromolecular matrix and hardening of the particles of agent by solvent removal takes place by lyophilization of the bulk matrix, which stabilizes the drug particles during hardening and prevents coalesence, thereby resulting in smaller final drug particles. The method is particularly preferred for protein agents. The process can be used in conjunction with a standard microencapsulation technique, typically following separation of the agent from the macromolecular matrix. The process yields microparticles having a homogenous size distribution, preferably less than 2 &#x3bc;m, and more preferably less than 1 &#x3bc;m, in size. The microparticles have well defined, predictable properties, which is particularly critical in drug delivery applications.

Micronized freeze-dried particles

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/in , preferably between about 2 and 10 metric tons/in , 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.

Liquid crystalline polymers

The invention involves methods and products for oral gene therapy. Genes under the control of promoters are protectively contained in microparticles and delivered to cells in operative form, thereby obtaining noninvasive gene delivery for gene therapy.

Method for gene therapy using nucleic acid loaded polymeric microparticles

A process for preparing nanoparticles and microparticles is provided. The process involves forming a mixture of a polymer and a solvent, wherein the solvent is present in a continuous phase and introducing the mixture into an effective amount of a nonsolvent to cause the spontaneous formation of microparticles.

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Providence, RI, United States of America

Yong S Jong