Abstract: A method for preparing microparticles having a selected polymer molecular weight. The hold time and temperature of a solution containing a nucleophilic compound and a polymer having a starting molecular weight are controlled in order to control the molecular weight of the polymer in the finished microparticle product. In this manner a selected polymer molecular weight in the finished microparticle product can be achieved from a variety of starting material molecular weights.

Abstract: Methods for preparing microparticles having improved flowability to facilitate processing in automated equipment. Microparticles are maintained at a conditioning temperature for a period of time. The conditioning temperature and period are selected so that the angle of repose of the microparticles is less than about 28°.

Abstract: A method for preparing biodegradable, biocompatible microparticles. A first phase is prepared that includes a biodegradable, biocompatible polymer, an active agent, and a solvent. A second phase is prepared. The first and second phases are combined to form an emulsion in which the first phase is discontinuous and the second phase is continuous. The discontinuous first phase is separated from the continuous second phase. The residual level of solvent in the discontinuous first phase is reduced to less than about 2% by weight.

Abstract: An improved method for preparing microparticles that exhibit controlled release of an effective amount of an active agent over an extended period of time. More particularly, a method is provided for preparing microparticles having a selected release profile for release of active agent contained in the microparticles. By adjusting the degree of drying that is performed during the preparation of the microparticles, the release profile can be controlled. By performing no intermediate drying, an initial burst and a substantially linear release profile is achieved. By performing substantially complete intermediate drying, an initial lag phase and a substantially sigmoidal release profile is achieved.

Abstract: A method for preparing microparticles having a selected polymer molecular weight. The hold time and temperature of a solution containing a nucleophilic compound and a polymer having a starting molecular weight are controlled in order to control the molecular weight of the polymer in the finished microparticle product. In this manner, a selected polymer molecular weight in the finished microparticle product can be achieved from a variety of starting material molecular weights.

Abstract: A method for preparing biodegradable, biocompatible microparticles. A first phase is prepared that includes a biodegradable, biocompatible polymer, an active agent, and a solvent. A second phase is prepared. The first and second phases are combined to form an emulsion in which the first phase is discontinuous and the second phase is continuous. The discontinuous first phase is separated from the continuous second phase. The residual level of solvent in the discontinuous first phase is reduced to less than about 2% by weight.

Abstract: A method for preparing microparticles having a selected polymer molecular weight. The hold time and temperature of a solution containing a nucleophilic compound and a polymer having a starting molecular weight are controlled in order to control the molecular weight of the polymer in the finished microparticle product. In this manner, a selected polymer molecular weight in the finished microparticle product can be achieved from a variety of starting material molecular weights.

Abstract: A method for preparing biodegradable, biocompatible microparticles. A first phase is prepared that includes a biodegradable, biocompatible polymer, an active agent, and a solvent. A second phase is prepared. The first and second phases are combined to form an emulsion in which the first phase is discontinuous and the second phase is continuous. The discontinuous first phase is separated from the continuous second phase. The residual level of solvent in the discontinuous first phase is reduced to less than about 2% by weight.

Abstract: A method for preparing microparticles having a selected polymer molecular weight. The hold time and temperature of a solution containing a nucleophilic compound and a polymer having a starting molecular weight are controlled in order to control the molecular weight of the polymer in the finished microparticle product. In this manner, a selected polymer molecular weight in the finished microparticle product can be achieved from a variety of starting material molecular weights.

Abstract: An improved method for preparing microparticles that exhibit controlled release of an effective amount of an active agent over an extended period of time. More particularly, a method is provided for preparing microparticles having a selected release profile for release of active agent contained in the microparticles. By adjusting the degree of drying that is performed during the preparation of the microparticles, the release profile can be controlled. By performing no intermediate drying, an initial burst and a substantially linear release profile is achieved. By performing substantially complete intermediate drying, an initial lag phase and a substantially sigmoidal release profile is achieved.

Abstract: A method for preparing biodegradable, biocompatible microparticles. A first phase is prepared that includes a biodegradable, biocompatible polymer, an active agent, and a solvent. An immiscible second phase is prepared. The first and second phases are combined to form an emulsion in which the first phase is discontinuous and the second phase is continuous. The two phases are immersed in a quench liquid that includes a quench medium and a quantity of the solvent. The quantity of the solvent is selected to control a rate of extraction of the solvent from the first phase. The first phase is isolated in the form of microparticles. Also disclosed is a microencapsulated active agent prepared by the method for preparing biodegradable, biocompatible microparticles.

Abstract: A method for preparing biodegradable, biocompatible microparticles. A first phase is prepared that includes a biodegradable, biocompatible polymer, an active agent, and a solvent. An immiscible second phase is prepared. The first and second phases are combined to form an emulsion in which the first phase is discontinuous and the second phase is continuous. The two phases are immersed in a quench liquid that includes a quench medium and a quantity of the solvent. The quantity of the solvent is selected to control a rate of extraction of the solvent from the first phase. The first phase is isolated in the form of microparticles. Also disclosed is a microencapsulated active agent prepared by the method for preparing biodegradable, biocompatible microparticles.

Abstract: A method for preparing biodegradable, biocompatible microparticles. A first phase is prepared that includes a biodegradable, biocompatible polymeric encapsulating binder, and an active agent having limited water solubility dissolved or dispersed in a solvent. An aqueous second phase is prepared. The first and second phases are combined to form an emulsion in which the first phase is discontinuous and the second phase is continuous. The two phases are separated. The discontinuous first phase is washed with water, or an aqueous solution of water and a solvent for residual solvent in the first phase, to reduce the level of residual solvent in the microparticles to less than about 2% by weight of the microparticles. Also disclosed are a microencapsulated drug prepared by the method for preparing biodegradable, biocompatible microparticles, and a pharmaceutical composition that includes biodegradable and biocompatible microparticles in a pharmaceutically acceptable carrier.

Abstract: Disclosed herein is a process for preparing biodegradable microparticles comprising a biodegradable polymeric binder and a biologically active agent, wherein a blend of at least two substantially non-toxic solvents, free of halogenated hydrocarbons, is used to dissolve or disperse the agent and dissolve the polymer. The solvent blend containing the agent and polymer is dispersed in an aqueous solution to form microdroplets. The resulting emulsion is then added to an extraction medium preferably containing at least one of the solvents of the blend, whereby the rate of extraction of each solvent is controlled, whereupon the biodegradable microparticles containing the biologically active agent are formed.