Abstract: Apparatus and method for preparing microparticles using in-line solvent extraction. An emulsion is formed by combining two phases in a static mixer. The emulsion is combined with an extraction liquid in a blending static mixer. The outflow of the blending static mixer is combined with additional extraction liquid. The additional extraction liquid and the outflow of the blending static mixer can be combined in a vessel, or through the use of a static mixer manifold that includes a plurality of static mixers.

Abstract: Copolymers of lactide and glycolide with high glycolide content. The average glycolate block length is less then about 3, which allows the copolymer to be soluble in slightly polar solvents such as methylene chloride.

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: Sustained-release microparticle composition. The microparticle composition can be formulated to provide multi-phasic release. In one aspect, the composition includes microparticles having more than one rate of release. In another aspect, the composition includes microparticles that exhibit diffusional release and microparticles that exhibit biodegradation release.

Abstract: Apparatus and method for preparing microparticles. An emulsion is formed by combining two phases in a static mixing assembly. The static mixing assembly preferably includes a preblending static mixer and a manifold. The emulsion flows out of the static mixing assembly into a quench liquid whereby droplets of the emulsion form microparticles. The residence time of the emulsion in the static mixing assembly is controlled to obtain a predetermined particle size distribution of the resulting microparticles.

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: Apparatus and method for preparing microparticles using in-line solvent extraction. An emulsion is formed by combining two phases in a static mixer. The emulsion is combined with an extraction liquid in a blending static mixer. The outflow of the blending static mixer is combined with additional extraction liquid. The additional extraction liquid and the outflow of the blending static mixer can be combined in a vessel, or through the use of a static mixer manifold that includes a plurality of static mixers.

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: Methods for preparing microparticles having reduced residual solvent levels. Microparticles are contacted with a non-aqueous washing system to reduce the level of residual solvent in the microparticles. Preferred non-aqueous washing systems include 100% ethanol and a blend of ethanol and heptane. A solvent blend of a hardening solvent and a washing solvent can be used to harden and wash microparticles in a single step, thereby eliminating the need for a post-hardening wash step.

Abstract: Sustained-release microparticle composition. The microparticle composition can be formulated to provide multi-phasic release. In one aspect, the composition includes microparticles having more than one rate of release. In another aspect, the composition includes microparticles that exhibit diffusional release and microparticles that exhibit biodegradation release.

Abstract: Apparatus and method for preparing microparticles using in-line solvent extraction. An emulsion is formed by combining two phases in a static mixer. The emulsion is combined with an extraction liquid in a blending static mixer. The outflow of the blending static mixer is combined with additional extraction liquid. The additional extraction liquid and the outflow of the blending static mixer can be combined in a vessel, or through the use of a static mixer manifold that includes a plurality of static mixers.

Abstract: Apparatus and method for preparing microparticles. An emulsion is formed by combining two phases in a static mixing assembly. The static mixing assembly preferably includes a preblending static mixer and a manifold. The emulsion flows out of the static mixing assembly into a quench liquid whereby droplets of the emulsion form microparticles. The residence time of the emulsion in the static mixing assembly is controlled to obtain a predetermined particle size distribution of the resulting microparticles.

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: Method and apparatus for preparing microparticles using liquid-liquid extraction. A first phase and a second phase are combined to form an emulsion. A portion of the second phase is separated from the emulsion (solvent rich), and the solvent is extracted from the separated second phase, which is then returned (solvent poor) to the emulsion. This process of separation of a solvent rich phase, extraction of solvent, and return of a solvent poor phase, is carried out until a selected level of solvent in the emulsion is achieved. Alternatively, the separated solvent rich phase is not returned to the emulsion, but replaced with another solution, such as an aqueous solution, that is free from solvent. The solvent is preferably extracted into an extraction liquid that functions as a “solvent sink” for the solvent.

Abstract: Method and apparatus for preparing microparticles using liquid-liquid extraction. A first phase and a second phase are combined to form an emulsion. A portion of the second phase is separated from the emulsion (solvent rich), and the solvent is extracted from the separated second phase, which is then returned (solvent poor) to the emulsion. This process of separation of a solvent rich phase, extraction of solvent, and return of a solvent poor phase, is carried out until a selected level of solvent in the emulsion is achieved. Alternatively, the separated solvent rich phase is not returned to the emulsion, but replaced with another solution, such as an aqueous solution, that is free from solvent. The solvent is preferably extracted into an extraction liquid that functions as a “solvent sink” for the solvent.

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: Apparatus and method for preparing microparticles. An emulsion is formed by combining two phases in a static mixing assembly. The static mixing assembly preferably includes a preblending static mixer and a manifold. The emulsion flows out of the static mixing assembly into a quench liquid whereby droplets of the emulsion form microparticles. The residence time of the emulsion in the static mixing assembly is controlled to obtain a predetermined particle size distribution of the resulting microparticles.

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.