Alkermes Controlled Therapeutics, Inc.

Enzytech, Ltd.

Larry R. Brown

Michael S. Healy

Wayne Gombotz

Henry E. Auer

Wayne R. Gombotz

Michael S Healy

Paul F Herbert

Larry Richard Brown

Wayne R Gombotz

Henry E Auer

The present invention relates to a method for forming microparticles of a material from microdroplets of a solution, wherein the solution comprises the material dissolved in a solvent. The method includes the steps of directing the microdroplets into a freezing zone, wherein the freezing zone is surrounded by a liquified gas, and wherein the microdroplets freeze. The frozen microdroplets are then mixed with a liquid non-solvent, whereby the solvent is extracted into the non-solvent, thereby forming the microparticles.

Production scale method of forming microparticles

Small diameter particles of biologically active molecules are produced by atomizing solutions of the molecules through a nozzle into very cold liquified gases, which immediately freeze the atomized droplets. The resulting frozen particles having diameters of approximately 10 to 90 micrometers are lyophilized to produce porous particles, suspended in a non-solvent for the molecules, and exposed to ultrasonic energy or homogenization to produce particles having diameters of 0.1 to 10 micrometers with greater than 70 to 95% of the initial biological activity of the molecules in solution.

Process for producing small particles of biologically active molecules

The present invention relates to a method for forming microparticles of a material from microdroplets of a solution, wherein the solution comprises the material dissolved in a solvent. The method includes the steps of directing the microdroplets into a freezing zone, whereby the microdroplets freeze. The frozen microdroplets are then contacted with a liquid non-solvent to extract the solvent into the non-solvent, thereby forming the microparticles.

A process for preparing microspheres using very cold temperatures to freeze polymer-biologically active agent mixtures into polymeric microspheres with very high retention of biological activity and material. Polymer is dissolved in a solvent together with an active agent that can be either dissolved in the solvent or dispersed in the solvent in the form of microparticles. The polymer/active agent mixture is atomized into a vessel containing a liquid non-solvent, alone or frozen and overlayed with a liquified gas, at a temperature below the freezing point of the polymer/active agent solution. The cold liquified gas or liquid immediately freezes the polymer droplets. As the droplets and non-solvent for the polymer is warmed, the solvent in the droplets thaws and is extracted into the non-solvent, resulting in hardened microspheres.

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East Bridgewater, MA, United States of America

Michael S Healy