Microcapsules and methods for making
Patent 5827531 Issued on October 27, 1998. Estimated Expiration Date: 
October 27, 2015. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
October 27, 2015. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3639306 Method of preparing microspheres for intravascular delivery Masking of liposomes from RES recognition Method of producing high aqueous volume multilamellar vesicles Apparatus for mixing solutions in low gravity environments Liposomes with enhanced circulation time Paucilamellar lipid vesicles using charge-localized, single chain, nonphospholipid surfactants Method of amphiphatic drug loading in liposomes by pH gradient Neutral glycolipid as an adsorbent for enteric viral pathogens Microreservoir liposome composition and method Patent #: 5225212 InventorsAssigneeApplicationNo. 349169 filed on 12/02/1994US Classes:424/450, Liposomes264/4.32, Microcapsule wall containing two or more layers264/4.33, Microcapsule wall derived from synthetic polymer424/451, Capsules (e.g., of gelatin, of chocolate, etc.)424/489, Particulate form (e.g., powders, granules, beads, microcapsules, and pellets)424/490, Coated (e.g., microcapsules)427/213.3, Solid encapsulation process utilizing an emulsion or dispersion to form a solid-walled microcapsule (includes liposome)428/402.21, Solid-walled microcapsule from synthetic polymer428/402.24Microcapsule with solid core (includes liposome)ExaminersPrimary: Page, Thurman K.Assistant: Spear, James M. Attorney, Agent or FirmInternational ClassesA61K 009/50A61K 009/52 AbstractMethods of forming multi-lamellar microcapsules having alternating layers of hydrophilic and hydrophobic immiscible liquid phases have been developed using different polymer/solvent systems. The methods use liquid-liquid diffusion and simultaneous lateral phase separation, controlled by proper timed-sequence exposures of immiscible phases and low shear mixing, to form narrow size distributions of spherical, multilamellar microcapsules. The use of special formulations of solubilized drugs, surfactants, and polymeric co-surfactants in aqueous vehicles which are dispersed in hydrocarbon solvents containing small quantities of oil, low molecular weight co-surfactants and glycerides that are aqueous insoluble enables the formation of unique microcapsules which can carry large amounts of pharmaceuticals in both aqueous and non-aqueous solvent compartments. The liquid microcapsules are quickly formed in a single step and can include a polymeric outer "skin" which protects the microcapsules during physical manipulation or exposure to high shear forces. Water-in-oil and oil-in-water microcapsules have been formed both in 1×g and in microgravity, which contain several types of drugs co-encapsulated within different fluid compartments inside the same microcapsule. Large, spherical multi-lamellar microcapsules have been formed including a cytotoxic drug co-encapsulated with a radiocontrast medium which has advantages for chemoembolization of vascular tumors. In certain cases, crystals of the drug form inside the microcapsules providing zero-order and first order, sustained drug release kinetics.Other References
Field of SearchLiposomesParticulate form (e.g., powders, granules, beads, microcapsules, and pellets) Coated (e.g., microcapsules) Solid encapsulation process utilizing an emulsion or dispersion to form a solid-walled microcapsule (includes liposome) Solid-walled microcapsule from synthetic polymer Microcapsule with solid core (includes liposome) Microcapsule wall containing two or more layers Microcapsule wall derived from synthetic polymer | |
