Solid-walled Microcapsule Formed From Preformed Synthetic Polymer Patents (Class 427/213.36)
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Patent number: 7056554Abstract: The invention concerns a method for producing nanocapsules and microcapsules comprising a polyelectrolyte shell by surface precipitation from the solution, by applying a shell to template particles comprising the steps (a) providing a dispersion of template particles of suitable size in a salt-containing liquid phase which contains the components required to form the shell in a dissolved form and (b) precipitating the components from the liquid phase onto the template particles under conditions which enable the formation of a shell around the template particles that has a thickness of from 1 to 100 nm.Type: GrantFiled: August 1, 2001Date of Patent: June 6, 2006Assignee: Max-Planck-Gesellschaft zur Forderung der Wissenschaften E.V.Inventors: Andreas Voigt, Gleb Sukhorukov, Igor Radtchenko, Alexei Antipov, Edwin Donath, Helmuth Möhwald
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Patent number: 7033609Abstract: A parenterally administrable, biodegradable microparticle preparation containing a biologically active substance which, during the first 24 hours after injection, exhibits a release of the active substance that is less than 25% of the total release, determined from a concentration-time curve in the form of the ratio between the area under the curve during the said first 24 hours and the total area under the curve in questionType: GrantFiled: January 10, 2002Date of Patent: April 25, 2006Assignee: Jagotec AGInventors: Nils Ove Gustavsson, Monica Jönsson, Timo Laakso, Mats Reslow, Sören Björn, Jörn Drustrup
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Patent number: 7011776Abstract: An improved method for the preparation of a microsphere from an emulsion wherein an organic phase containing an organic solvent having a boiling point lower than that of water and a hardly-water-soluble polymer is emulsified in an aqueous phase by an in-water drying method, which method includes: (1) providing a gas separation membrane; (2) supplying the emulsion to be subjected to in-water drying to one side of the gas separation membrane; and (3) evaporating off the organic solvent contained in the emulsion to the other side of the gas separation membrane, which can remove the organic solvent with high efficiency and can be carried out in a closed system and hence is favorable from an environmental viewpoint.Type: GrantFiled: April 26, 2001Date of Patent: March 14, 2006Assignee: Tanabe Seiman Co., ltd.Inventors: Takehiko Suzuki, Yasuhisa Matsukawa, Akira Suzuki
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Patent number: 6962716Abstract: A cost-effective, scalable technique for producing microspheres loaded with biologically active solid proteins is provided. The microspheres degrade over time and release biologically active VEGF, as demonstrated by the proliferation of HUVECs in vitro compared to negative controls. A defined concentration of microspheres can deliver a quantifiable level of VEGF with known release kinetics. The invention can be used with other growth factors and applied to tissue engineering applications such as the regeneration of peripheral nerve, bone, adipose tissue, and solid organs.Type: GrantFiled: September 27, 2000Date of Patent: November 8, 2005Assignee: Board of Regents, The University of Texas SystemInventors: Timothy W. King, Charles W. Patrick, Jr.
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Patent number: 6932984Abstract: A method for microencapsulation of substances is provided. The substance(s) is/are dissolved or dispersed in an organic solvent of the kind that is partially miscible in water media. This organic solution is then mixed with an aqueous solution, which is saturated with an organic solvent and an emulsifier to form an emulsion. The emulsion is then poured into water under continuous agitation for the extraction of residual solvent. The formation of the solid capsules takes place during this extraction process. The capsules are undergone to further purification, whereby the microcapsules can be separated from the water and dried. By conditions of incubation of microcapsules in water-containing formulations the wall-softening process takes place. The unique system for controlled releasing the ingredients from microcapsules is based on the above-mentioned process.Type: GrantFiled: November 16, 2000Date of Patent: August 23, 2005Assignee: Tagra Biotechnologies Ltd.Inventors: Vladimir Babtsov, Yury Shapiro, Emma Kvitnitsky
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Patent number: 6911218Abstract: A method of spherifying a sustained release ionic conjugate which contains a free carboxyl group-containing biodegradable polymer and a free amino group-containing drug which are ionically bonded to each other.Type: GrantFiled: April 22, 1997Date of Patent: June 28, 2005Assignee: Ipsen Manufacturing Ireland LimitedInventors: Francis Xavier Ignatious, Thomas Ciaran Loughman, Shalaby Wahba Shalaby, Franck Jean-Claude Touraud
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Patent number: 6884829Abstract: A polymer with a hemocompatible film or coating is manufactured by a one-step method comprising polymerizing monomer droplets comprising at least one crosslinking agent to form a polymer and simultaneously coating the resulting polymer using at least one dispersing agent to thereby form a hemocompatible coated polymer.Type: GrantFiled: October 18, 2002Date of Patent: April 26, 2005Inventor: Robert L. Albright
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Patent number: 6844026Abstract: A subject matter of the invention is a process for the preparation of particles comprising at least one metal ion, which comprises the stage of bringing into contact a precursor a metal cation, optionally partially hydrolyzed, with at least one water-soluble comb copolymer. Likewise, a subject matter of the invention is particles capable of being prepared according to the process of the invention, said particles exhibiting a mean size of between 2 and 500 nm and preferably between 2 and 300 nm. Finally, it relates to the use of such particles in the mechanical polishing of hard objects, in the preparation of pigments or mixed ceramics for the electronic industry, in the reinforcing of polymeric matrices, in fungicidal or biocidal dispersions, in the scavenging of sulfur derivatives or the scavenging of unpleasant smells.Type: GrantFiled: February 12, 2001Date of Patent: January 18, 2005Assignee: Rhodia ChimieInventors: Olivier Anthony, Corine Gerardin, Nathalie Cadena, Marie-Pierre Labeau
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Patent number: 6767637Abstract: A method for generating a plurality of drug-containing microcapsules employs one or more atomizers to form the microcapsules by the phenomenon of solvent exchange. A plurality of microdroplets of an aqueous solution is contacted with a plurality of microdroplets containing a polymer dissolved in a hydrophilic solvent under conditions whereby the polymer solution envelops the aqueous microdroplet. Exchange of solvent molecules between the aqueous core and its polymer-containing shell deposits the polymer as a membrane around the aqueous core. A preferred atomizer is a coaxial ultrasonic atomizer. Microcapsules can be generated in air as well as when submersed in a collection bath. Desired properties of the microcapsules, e.g., controlled release, can be achieved by providing protective excipients within the aqueous core, providing a hydrophilic polymer capable of undergoing a sol-to-gel transition within the aqueous core, optimizing selection of the polymer solvent, adjusting relative flow rates, and the like.Type: GrantFiled: March 19, 2003Date of Patent: July 27, 2004Assignee: Purdue Research FoundationInventors: Kinam Park, Yoon Yeo
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Patent number: 6737108Abstract: A process for producing a MC-type conductive filler includes treating minute metallic particles with a coupling agent, preparing an oil phase of the coupling agent-treated minute metallic particles and a reactive substance A, the reactive substance A directly contacting the metallic particles. Then, an aqueous phase is prepared having a reactive substance B, which is capable of reacting with the reactive substance A, dissolved in water. Thereafter, the oil phase is dispersed in the aqueous phase to form a suspension. In situ reaction of the reactive substances A and B is then caused by applying heat to the suspension or adding a catalyst to the suspension. This forms a coating of a thermosetting insulating resin on the surface of the minute metallic particles. Alternatively, the reactive substance B may not be used.Type: GrantFiled: May 14, 2002Date of Patent: May 18, 2004Assignee: Fujitsu LimitedInventors: Hiroaki Date, Makoto Usui, Isao Watanabe, Yuko Hozumi
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Publication number: 20040070093Abstract: 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.Type: ApplicationFiled: August 12, 2003Publication date: April 15, 2004Applicant: Brown University Research FoundationInventors: Edith Mathiowitz, Donald Chickering, Yong S. Jong, Jules S. Jacob
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Patent number: 6713090Abstract: 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.Type: GrantFiled: January 31, 2003Date of Patent: March 30, 2004Assignee: Alkermas Controlled Therapeutics Inc. IIInventors: Shawn L. Lyons, Steven G. Wright
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Patent number: 6692667Abstract: A method of making phosphorescent fiber having phosphorescent particles composed, by weight, of 55-62.5% of strontium oxide, 35-42.5% of aluminum oxide, 1-9% of dysprosium oxide and 0.5-1.5% of europium oxide encapsulated with a wall material. The encapsulated particles are mixed and pelletized at a weight ratio of 15-25:85-75 with polymer capable of fiber formation to give a master batch, which is then compounded at a weight ratio of 30-70:70-30 with a polymer mixture, in combination with a softener and a dispersing agent. Polymer mixture consists of two polymers. One is the same polymer used to produce a master batch, the other is a polymer in the same chemical structure but different in physical properties such as melt index and tenacity. The compounded chip is melt-spun at 190-290° C. through a melt extruder. The fibers with the encapsulated phosphorescent particles exhibit such excellent physical properties as to be applicable to various textile products and show a high degree of luminescence.Type: GrantFiled: March 7, 2001Date of Patent: February 17, 2004Assignees: Glowyarn Co., Ltd.Inventor: Kang Kyeng-Jung
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Patent number: 6660382Abstract: The invention concerns a method for making coated granules with masked taste and instant release of the active principle which consists in: first, mixing the constituents of a powder comprising at least the active principle and a granular disintegrating agent; then, granulating the resulting powder, in the presence of a mixture of carriers comprising at least a binding agent capable of binding the particles together to obtain grains; coating the grains formed by spraying a suspension comprising at least a coating agent and a membrane disintegrating agent; finally drying the resulting coated granules.Type: GrantFiled: January 8, 2002Date of Patent: December 9, 2003Assignee: EthypharmInventors: Noureddine Nouri, Jean-Marc Zuccarelli, Charles Chauveau, Etienne Bruna
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Patent number: 6616869Abstract: 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.Type: GrantFiled: May 11, 2001Date of Patent: September 9, 2003Assignee: Brown University Research FoundationInventors: Edith Mathiowitz, Donald Chickering, III, Yong S. Jong, Jules S. Jacob
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Publication number: 20030152860Abstract: A process for forming microcapsules having substantially impermeable microcapsule walls comprising the steps of: forming an emulsion of an internal phase in a continuous aqueous phase, the internal phase including a photosensitive composition and a polyvalent isocyanate, the continuous aqueous phase including a sulfonated polystyrene, at least one of the internal phase or the continuous aqueous phase further including a hydrophilic polymer; and enwrapping particles of the internal phase in an amine-formaldehyde condensation product produced by in situ condensation of an amine and formaldehyde is disclosed.Type: ApplicationFiled: March 17, 2000Publication date: August 14, 2003Inventors: Ibrahim Katampe, Joseph C. Camillus
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Patent number: 6599627Abstract: A solvent exchange method is employed to provide microencapsulated compositions, such as microcapsules of pharmaceutical preparations. The method is based on an exchange of water and a hydrophilic organic solvent, whereby a decline in solvent quality for the organic solvent causes a polymer dissolved therein to be deposited onto an aqueous core. Optimal results are rationalized in terms of a balance of water solubility and surface tension for the organic solvent. In a preferred embodiment, microcapsules of selected drugs are formed by contacting microdroplets of an aqueous solution containing the drug with the organic solvent containing a polymer dissolved therein. A preferred method employs biodegradable poly(lactic acid-co-glycolic acid) (PLGA) dissolved in acetic acid, ethyl acetate, methyl acetate, or ethyl formate, to form a PLGA membrane around an aqueous drug core. The method is particularly attractive for encapsulating protein-based drugs without substantial denaturation.Type: GrantFiled: December 13, 2001Date of Patent: July 29, 2003Assignee: Purdue Research FoundationInventors: Yoon Yeo, Alvin Un-Teh Chen, Osman A. Basaran, Kinam Park
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Patent number: 6565777Abstract: Bioactive agent is encapsulated in a polymer microparticle in a (water-in-oil)-in-water emulsion-based method, and using a solvent that comprises ethyl acetate. Also described are microparticles comprising low inherent viscosity (i.v.) PLG, some with i.v. less than 0.5 dl/g, and methods for their preparation. DNA release is modified through use of low i.v. PLG. A particle production method for scale-up uses a blender that avoids excessive shear damage to DNA being encapsulated.Type: GrantFiled: May 29, 2002Date of Patent: May 20, 2003Assignee: Microbiological Research AuthorityInventors: Graham Henry Farrar, Anne Margaret Tinsley-Bown, David Hughes Jones
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Patent number: 6544559Abstract: 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.Type: GrantFiled: January 29, 2002Date of Patent: April 8, 2003Assignees: Alkermes Controlled Therapeutics Inc. II, Janssen ParmaceuticaInventors: Jean Mesens, Michael E. Rickey, Thomas J. Atkins
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Patent number: 6537586Abstract: 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.Type: GrantFiled: April 1, 2002Date of Patent: March 25, 2003Assignee: Alkermes Controlled Therapeutics Inc. IIInventors: Shawn L. Lyons, Steven G. Wright
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Patent number: 6534092Abstract: 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.Type: GrantFiled: February 14, 2002Date of Patent: March 18, 2003Assignee: Alkermes Controlled Therapeutics, Inc. IIInventors: Steven G. Wright, Michael E. Rickey, J. Michael Ramstack, Shawn L. Lyons, Joyce M. Hotz
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Patent number: 6503762Abstract: A novel magnetic carrier is provided which comprises particulate silica containing a magnetic material, having polyacrylamide on the surface thereof in an amount ranging from 0.3 to 5 mmol/g in terms of monomeric acrylamide. A process for producing the magnetic carrier is also provided in which the surface of particulate silica containing a magnetic material is treated with a coupling agent, and the treated particulate silica is reacted with acrylamide and/or polyacrylamide. The magnetic carrier is useful for extraction of nucleic acid. The magnetic carrier can be produced readily by controlling the shape, the particle diameter, and the pore diameter, and is excellent in strength and adsorption efficiency. The extraction of a nucleic acid can be automated by use of the magnetic carrier.Type: GrantFiled: November 1, 2000Date of Patent: January 7, 2003Assignee: Tosoh CorporationInventors: Syoichi Yamauchi, Kiyoshi Kasai
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Patent number: 6503559Abstract: The present invention relates to colorant compositions containing neonanoplasts. The colorant compositions exhibit improved color brightness and brilliance due to the incorporation of one or more colorants in the neonanoplasts. The colorant compositions may be printed onto virtually any substrate. The colorant compositions of the present invention have particular utility in the area of printed textiles.Type: GrantFiled: June 3, 1999Date of Patent: January 7, 2003Assignee: Kimberly-Clark Worldwide, Inc.Inventors: Ronald Sinclair Nohr, John Gavin MacDonald
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Patent number: 6500534Abstract: The invention relates to powder-coated substrates bearing on a powder-coated surface a scratch-resistant and abrasion-resistant topcoat of a coating material which comprises: a) condensates based on hydrolyzable silanes containing at least one non-hydrolyzable substituent, the hydrolyzable silanes having an epoxide group on at least one non-hydrolyzable substituent; b) a curing catalyst selected from Lewis bases and alkoxides of titanium, zirconium or aluminium; c) nanoscale particulate inorganic solids having a particle size in the range from 1 to 100 nm; and d) at least one organic monomer, oligomer or polymer containing at least one epoxide group.Type: GrantFiled: November 21, 2000Date of Patent: December 31, 2002Assignee: Institut Für Neue Materialien gemeinnützige GmbHInventors: Carola Dittfurth, Stefan Sepeur, Ralf-Peter Winkler, Helmut Schmidt
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Patent number: 6444261Abstract: A particle resistant to storage of at least one first and at least one second component, wherein said second component of at least one crosslinkable polymer as a shell at least partially envelops and/or encloses said first component as a core and said first component has at least one ascertainable property, obtainable by reacting said first component with the crosslinkable polymer and subsequently reacting the formed product with a crosslinking agent such that the first component with resistance to storage remains within the second component.Type: GrantFiled: July 20, 1998Date of Patent: September 3, 2002Assignee: Abion Beteiligungs-und Verwaltungsgesellschaft mbHInventors: Dmitri Plaksine, Elena Gromakovskaia, Christoph Erhardt
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Patent number: 6440493Abstract: Processes for making microparticles, preferably containing an active agent, are provided. In a preferred embodiment, the process involves preparing (1) a dispersed phase containing an agent in a solution of polymer and a first solvent; (2) a continuous phase containing a surfactant, and a second solvent that is totally or partially immiscible with the first solvent; and (3) an extraction phase that is a nonsolvent for the polymer, a solvent for the continuous phase components, and a solvent for the first solvent, wherein the first solvent has solubility in the extraction phase of between about 0.1% and 25% by weight. Then, the dispersed phase and the continuous phase are mixed to form an emulsion, and the emulsion is then briefly mixed with a suitable quantity of extraction phase to induce skin formation at the interface of the dispersed and continuous phases. Remaining solvent is removed by an evaporation process step.Type: GrantFiled: November 29, 2000Date of Patent: August 27, 2002Assignee: Southern Biosystems, Inc.Inventors: John W. Gibson, Richard J. Holl, Arthur J. Tipton
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Patent number: 6406746Abstract: A process for producing a MC-type conductive filler includes treating minute metallic particles with a coupling agent, preparing an oil phase of the coupling agent-treated minute metallic particles and a reactive substance A, the reactive substance A directly contacting the metallic particles. Then, an aqueous phase is prepared having a reactive substance B, which is capable of reacting with the reactive substance A, dissolved in water. Thereafter, the oil phase is dispersed in the aqueous phase to form a suspension. In situ reaction of the reactive substances A and B is then caused by applying heat to the suspension or adding a catalyst to the suspension. This forms a coating of a thermosetting insulating resin on the surface of the minute metallic particles. Alternatively, the reactive substance B may not be used.Type: GrantFiled: March 1, 2000Date of Patent: June 18, 2002Assignee: Fujitsu LimitedInventors: Hiroaki Date, Makoto Usui, Isao Watanabe, Yuko Hozumi
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Patent number: 6395302Abstract: The invention relates to a method for the preparation of microencapsulated colloidal systems such as liposomes, i.e., microspheres which comprise colloidal systems. These microencapsulated colloidal systems can be used as controlled release systems for the delivery of active ingredients in in vivo and in vitro applications. A method is provided in which the colloidal systems are added to a phase which comprises a water soluble crosslinkable polymer followed by formation of microspheres.Type: GrantFiled: February 15, 2000Date of Patent: May 28, 2002Assignee: Octoplus B.V.Inventors: Wilhelmus Everhardus Hennink, Okke Franssen
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Patent number: 6395304Abstract: 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.Type: GrantFiled: April 10, 2001Date of Patent: May 28, 2002Assignee: Alkermes Controlled Therapeutics Inc. IIInventors: Shawn L. Lyons, Steven G. Wright
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Patent number: 6391338Abstract: The present invention is a method of preparing a system for delivering a bio-affecting agent and the composition prepared thereby. The invention includes forming a molecular dispersion of the bio-affecting agent in an increased energy state in a water-soluble polymer which is compatible with the bio-affecting agent. As a consequence of transforming the bio-affecting agent to an increased-energy condition and freezing it in such condition in a water-soluble polymer, the bio-affecting agent is made available (“bio-available”) to a bio-system upon dissolution of the polymer. This method and composition has been found extremely effective for delivery of otherwise substantially non-soluble drugs and other bio-affecting ingredients.Type: GrantFiled: August 21, 1998Date of Patent: May 21, 2002Assignee: Biovail Technologies Ltd.Inventors: Steven E. Frisbee, Garry L. Myers, Richard C. Fuisz, Andrea S. Blake, Robert K. Yang
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Patent number: 6379704Abstract: 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.Type: GrantFiled: June 1, 2001Date of Patent: April 30, 2002Assignee: Alkermes Controlled Therapeutics Inc. IIInventors: Steven G. Wright, Michael E. Rickey, J. Michael Ramstack, Shawn L. Lyons, Joyce M. Hotz
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Patent number: 6376078Abstract: Disclosed are spherical particles of a polyorganosilsesquioxane resin have a unique optical properties when each particle has a core-cladding composite structure consisting of a core portion of, for example, a polymethylsilsesquioxane resin and a cladding layer of, for example, a polyphenylsilsesquioxane resin having refractive indices differing by at least 0.02, the diameter of the core portion being in a specified range relative to the diameter of the whole particle. Such particles of a core-cladding structure can be prepared by conducting the hydrolysis-condensation reaction of organotrialkoxysilanes, e.g., methyl trimethoxysilane and phenyl trimethoxysilane, in two successive steps by using different silane compounds or by using silane mixtures of different mixing proportion in the first and second step reactions.Type: GrantFiled: June 2, 2000Date of Patent: April 23, 2002Assignee: Shin-Etsu Chemical Co., LtdInventor: Yoshinori Inokuchi
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Patent number: 6331317Abstract: 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.Type: GrantFiled: November 12, 1999Date of Patent: December 18, 2001Assignee: Alkermes Controlled Therapeutics II Inc.Inventors: Shawn L. Lyons, Steven G. Wright
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Patent number: 6309569Abstract: Bioactive agent is encapsulated in a polymer microparticle in a (water-in-oil)-in-water emulsion-based method, and using a solvent that comprises ethyl acetate. Also described are microparticles comprising low inherent viscosity (i.v.) PLG, some with i.v. less than 0.5dl/g, and methods for their preparation. DNA release is modified through use of low i.v. PLG. A particle production method for scale-up uses a blender that avoids excessive shear damage to DNA being encapsulated.Type: GrantFiled: May 13, 1999Date of Patent: October 30, 2001Assignee: Microbiological Research AuthorityInventors: Graham Henry Farrar, Anne Margaret Tinsley-Bown, David Hugh Jones
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Patent number: 6291013Abstract: Processes for making microparticles, preferably containing an active agent, are provided. In a preferred embodiment, the process involves preparing (1) a dispersed phase containing an agent in a solution of polymer and a first solvent; (2) a continuous phase containing a surfactant, a second solvent that is totally or partially immiscible with the first solvent, and sufficient first solvent to saturate the continuous phase; and (3) an extraction phase that is a nonsolvent for the polymer, a solvent for the continuous phase components, and a solvent for the first solvent, wherein the continuous phase solvent has solubility in the extraction phase of between about 0.1% and 25% by weight. Then, the dispersed phase and the continuous phase are mixed to form an emulsion, and the emulsion is then briefly mixed with a suitable quantity of extraction phase to induce skin formation at the interface of the dispersed and continuous phases. Remaining solvent is removed by an evaporation process step.Type: GrantFiled: May 3, 1999Date of Patent: September 18, 2001Assignee: Southern BioSystems, Inc.Inventors: John W. Gibson, Richard J. Holl, Arthur J. Tipton
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Patent number: 6274387Abstract: A novel magnetic carrier is provided which comprises particulate silica containing a magnetic material, having polyacrylamide on the surface thereof in an amount ranging from 0.3 to 5 mmol/g in terms of monomeric acrylamide. A process for producing the magnetic carrier is also provided in which the surface of particulate silica containing a magnetic material is treated with a coupling agent, and the treated particulate silica is reacted with acrylamide and/or polyacrylamide. The magnetic carrier is useful for extraction of nucleic acid. The magnetic carrier can be produced readily by controlling the shape, the particle diameter, and the pore diameter, and is excellent in strength and adsorption efficiency. The extraction of a nucleic acid can be automated by use of the magnetic carrier.Type: GrantFiled: December 28, 1998Date of Patent: August 14, 2001Assignee: Tosoh CorporationInventors: Syoichi Yamauchi, Kiyoshi Kasai
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Patent number: 6270700Abstract: This invention relates to a process for preparing biodegradable microspheres and or nanospheres using an oil-in-water process for the controlled release of bioactive peptides.Type: GrantFiled: July 20, 1999Date of Patent: August 7, 2001Assignee: Societe de Conseils de Recherches et d'Applications Scientifiques, SASInventor: Francis X. Ignatious
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Patent number: 6264987Abstract: 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.Type: GrantFiled: May 19, 2000Date of Patent: July 24, 2001Assignee: Alkermes Controlled Therapeutics Inc. IIInventors: Steven G. Wright, Michael E. Rickey, J. Michael Ramstack, Shawn L. Lyons, Joyce M. Hotz
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Patent number: 6235224Abstract: 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.Type: GrantFiled: November 18, 1999Date of Patent: May 22, 2001Assignee: Brown University Research FoundationInventors: Edith Mathiowitz, Donald Chickering, III, Yong S. Jong, Jules S. Jacob
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Patent number: 6224793Abstract: The invention is an encapsulated active agent comprising an active agent encapsulated in a crystallizable or thermoplastic polymer wherein the particle size of the encapsulated active agent is 3,000 microns or less wherein the active agent is not significantly extractable from the particles under ambient conditions. In another embodiment the invention is a process for preparing an encapsulated agent which comprises a) contacting an active agent with a crystallizable or thermoplastic polymer wherein the polymer is molten and the active agent in not volatile under the contacting conditions; b) forming particles of about 3000 microns or less; and c) exposing the particles to conditions such that the portion of the particle at and near the surface undergoes rapid solidification. The encapsulated active agents of the invention do not require washing in order for them to be stable in curable compositions. These encapsulated active agents can be designed to release the active agent at a desired temperature.Type: GrantFiled: April 27, 1999Date of Patent: May 1, 2001Assignees: The Dow Chemical Company, Landec CorporationInventors: Dwight K. Hoffman, Steven P. Bitler
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Patent number: 6224794Abstract: A process for forming microspheres that includes passing a first composition containing polymer and solvent through an orifice and directly into a second composition containing water and a microsphere-stabilizing agent, under at least one of conditions (a) and (b), wherein (a) the first composition flows through a first conduit along a first path and exits the first conduit at the orifice, the second composition flows through a second conduit along a second path in an upstream to downstream direction, the first conduit is connected to the second conduit and terminates at the orifice, the first and second paths being orientated at an angle &thgr; relative to each other, wherein 0°<&thgr;<180°; (b) the first composition being at a first temperature and including a solvent having a boiling point, the second composition being at a second temperature, the boiling point of the solvent being less than the second temperature; and forming a composition including water and microspheres, the microspheres bType: GrantFiled: May 5, 1999Date of Patent: May 1, 2001Assignee: Angiotech Pharmaceuticals, Inc.Inventors: Brian G. Amsden, Richard T. Liggins
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Patent number: 6217999Abstract: A photochemical reactor element containing microcapsulated TiO2 photocatalyst particles dispersed in a polysiloxane matrix is disclosed. The polysiloxane matrix has an oxygen gas permeability not less than 1×10−14 mol·m·m−2·s−1·Pa−1. The photochemical reactor element is produced by dispersing the microcapsulated or naked TiO2 photocatalyst particles in a hydrolyzate-polycondensate sol of a trialkoxysilane or a mixture thereof with a tetra- and/or dialkoxysilane and then shaping the dispersion into the element. The naked TiO2 photocatalyst particles in the element are microcapsulated within a porous silica shell layer in situ by irradiating the element with UV radiation.Type: GrantFiled: December 28, 1998Date of Patent: April 17, 2001Assignee: Nihon Yamamura Glass Co., Ltd.Inventors: Zuyi Zhang, Yoshinori Tanigami, Hideo Yamada, Hiroyuki Nishino
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Patent number: 6197349Abstract: Particles comprising (a) a supercooled melt of a poorly water-soluble substance and (b) a stabilizing agent, which have a mean particle size of between 30 and 500 nm, and disperse compositions containing them, as administration forms and delivery systems for drugs, vaccines and other biologically active agents such as herbicides, pesticides, insecticides, fungicides, fertilizers, vitamins, nutrition additives and cosmetics.Type: GrantFiled: November 6, 1997Date of Patent: March 6, 2001Assignee: Knoll AktiengesellschaftInventors: Kirsten Westesen, Britta Siekmann