Sustained release particles
AssigneeBiogram AB
InventorsNils-Ove Gustafsson, Timo Laakso, Peter Fyhr, Monica Jonsson
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Abstract
A method of preparing parenterally administrable sustained release microparticles, which comprises preparing core particles in an aqueous medium that is essentially free from organic solvent, a biologically active substance being entrapped therein during or after said preparation, drying the core particles and coating the same with a release-controlling polymer by air suspension technique so as to create a shell on the core particles without any detrimental exposure of the active substance to organic solvent. Microparticles obtainable by such a method also are provided.
Claims32
A method for preparing parenterally administerable, sustained release microparticles containing a biologically active substance, which method comprises (i) preparing core particles from a biodegradable material in an aqueous medium which substantially lacks any organic solvents which are detrimental to the activity of said active substance;
- such that said biologically active substance becomes entrapped in said particles during or after said preparation;
- (ii) drying said core particles containing said active substance;
- and (iii) coating said core particles with a film-forming, biodegradable, release-controlling polymer by an air suspension technique which results in the creation of a shell comprised of said polymer containing said core particles under condition that avoid exposure of the active substance to any detrimental organic solvent potentially detrimental to the activity of said active substance.
A method of coating small particles comprising applying to said small particles by an air suspension technique an emulsion comprising a polymeric coating material wherein one of the phases of said emulsion is a liquid of said polymeric coating material comprised in a solvent and the other phase is water.
Parenterally administrable sustained release microparticles, which comprise:
- (a) core particles of a biodegradable material and entrapped therein a biologically active substance which is sensitive to exposure to organic solvents, said core particles having been prepared in an aqueous medium essentially free from organic solvent to which said biologically active substance is sensitive;
- and
- (b) a shell, on said core particles, from a film-forming, biodegradable, release-controlling polymer;
- said shell having been applied on the core particles by means of air-suspension technique.
Dependencies are inferred from the claim text.