Microparticles
AssigneeJagotec AG
InventorsNils Ove Gustavsson, Monica Jonsson, Timo Laakso, Mats Reslow
Life of this patent
Estimating the term…
Abstract
A process for producing parenterally administrable microparticles, in which an at least 20% by weight aqueous solution of purified amylopectin-based starch of reduced molecular weight is prepared, the solution is combined with biologically active substance, an emulsion of starch droplets is formed in an outer phase of polymer solution, the starch droplets are made to gel, and the gelled starch particles are dried. A release-controlling shell is optionally also applied to the particles. Microparticles which essentially consist of said starch, have an amino acid content of less than 50 μg and have no covalent chemical cross-linking.
Claims46
A process for producing parenterally, preferably by injection, administrable microparticles containing a biologically active substance, which process comprises:
- a) preparing an aqueous starch solution, comprising starch which has an amylopectin content exceeding 85% by weight, in which the molecular weight of the said amylopectin has been reduced such that at least 80% by weight of the material is within the range of 10-10 000 kDa, and which has an amino acid nitrogen content of less than 50 μg per g dry weight of starch, the starch concentration of the solution being at least 20% by weight,
- b) combining the biologically active substance with the starch solution under such conditions that a composition in the form of a solution, emulsion or suspension of said substance in the starch solution is formed,
- c) mixing the composition obtained in step b) with an aqueous solution of a polymer having the ability of forming, a two-phase aqueous system, thereby forming an emulsion, of starch droplets which contain the biologically active substance as an inner phase in an outer phase of said polymer solution,
- d) causing or allowing the starch droplets obtained in step c) to gel into starch particles through the natural capacity of the starch to solidify,
- e) drying the starch particles, preferably after prior removal of said outer phase through washing, and
- f) optionally applying a release-controlling shell of a biocompatible and biodegradable polymer, preferably by air suspension technology, to the dried starch particles.
Microparticles suitable for parenteral administration, preferably via injection, to a mammal, especially a human, and containing a biologically active substance, which microparticles essentially consist of starch having an amylopectin content exceeding 85% by weight, of which at least 80% by weight has an average molecular weight within the range of 10-10 000 kDa and having an amino acid nitrogen content of less than 50 μg per gram dry weight of starch, and which have no covalent chemical cross-linking between the starch molecules.
Dependencies are inferred from the claim text.