Production method for sustained-release preparation
This invention provides a production method for a solid sustained-release preparation, characterized in that a sustained-release preparation (a sustained-release preparation suspension) is freeze-dried in a freeze-drying container whose inner face is partially or totally coated with an ice layer or water-repelling base material.
1 . A method for producing a solid sustained-release preparation, which comprises freeze-drying a sustained-release preparation in a freeze-drying container of which the inner face is partially or wholly coated with an ice layer or water-repelling base material:
wherein the ice layer has a thickness of about 0.1 mm to about 30 mm; and
wherein the water-repelling base material is ethylene tetrafluoride resin, ethylene trifluoride resin, ethylene difluoride resin, vinylidene fluoride resin, propylene hexafluoride-ethylene tetrafluoride copolymer resin, modified fluorine resin, ethylene tetrafluoride-perfluoroalkoxyethylene copolymer resin, or ethylene tetrafluoride-ethylene copolymer resin.
2 . A method for producing a solid sustained-release preparation, which comprises freeze-drying a sustained-release preparation in a freeze-drying container of which the inner face is partially or wholly coated with a water-repelling base material, and the coated inner face is further partially or wholly coated with an ice layer.
3 . The method according to claim 1 wherein the inner face is the bottom face alone.
4 . The method according to claim 1 wherein the freeze-drying container is a tray.
5 - 6 . (canceled)
7 . The method according to claim 1 wherein said sustained-release preparation is a microsphere.
8 . The method according to claim 1 which comprises completing the sublimation of frozen water in the freeze-drying container under reduced condition that the temperature in the freeze-drying container is 0° C. or below.
9 . The method according to claim 3 wherein said sustained-release preparation is a microsphere.
10 . The method according to claim 4 wherein said sustained-release preparation is a microsphere.
11 . The method according to claim 2 wherein the inner face is the bottom face alone.
12 . The method according to claim 2 wherein the freeze-drying container is a tray.
13 . The method according to claim 2 wherein said sustained-release preparation is a microsphere.
14 . The method according to claim 2 which comprises completing the sublimation of frozen water in the freeze-drying container under reduced condition that the temperature in the freeze-drying container is 0° C. or below.