Polymer microparticles for drug delivery
AssigneeDanbiosyst UK Limited
InventorsMing-Kung Yeh, Alan Gerald Coombes, Paul George Jenkins, Stanley Stewart Davis
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Abstract
Provided are biodegradable microparticles, which exhibit a linear release profile of active agent, and methods for making the microparticles. The microparticles include a mixture of a biodegradable polymer, a water soluble polymer, and an active agent. Preferred biodegradable polymers include lactide homopolymers or copolymers of lactide and glycolide, and preferred water soluble polymers include poly(ethylene glycol) (PEG) or PEG copolymers. The microparticles are made using an emulsion/solvent extraction method, in which the continuous phase of the secondary emulsion contains an organic solvent that is miscible with the organic solvent in the primary emulsion.
Claims26
A microparticle comprising a mixture of:
- (a) a biodegradable polymer,
- (b) a water soluble polymer which has a molecular weight of about 8000 Daltons or higher, and
- (c) an active agent;
- characterised in that the microparticle exhibits an active agent release profile which is substantially linear with time.
A microparticle comprising a mixture of:
- (a) a biodegradable polymer,
- (b) a water soluble polymer, and
- (c) an active agent;
- wherein the water soluble polymer is a block copolymer comprising PEG as one of the blocks.
A method of forming polymer microparticles containing an active agent comprising the steps of:
- a. forming an aqueous solution, water-in-oil (W/O) emulsion or a suspension of the active agent in a first organic solvent;
- b. mixing the aqueous solution, W/O emulsion or suspension of the active agent with a polymer solution formed in a second organic solvent;
- and
- c. mixing the emulsion so formed in step b. with a continuous phase comprising a third organic solvent which is miscible with the first and second organic solvents and is not a solvent for the polymer.
A method of administering an active agent to an animal or human comprising administering a microparticle comprising a mixture of
- (a) a biodegradable polymer,
- (b) a water soluble polymer, and
- (c) the active agent,
- wherein the microparticle exhibits an active agent release profile which is substantially linear with time.
Dependencies are inferred from the claim text.