Sustained release microcapsule
AssigneeTakeda Chemical Industries, Ltd.
InventorsMasaki Yamamoto, Shigeyuki Takada, Yasuaki Ogawa
Life of this patent
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Abstract
Microcapsules are advantageously produced with high take-up of a water-soluble drug by preparing a W/O emulsion composed of a water-soluble drug-containing solution as the inner aqueous phase and a polymer-containing solution as the oil phase, dispersing said emulsion in an aqueous phase and subjecting the resulting W/O/W emulsion to an in-water drying, wherein the viscosity of the W/O emulsion used in preparing the W/O/W emulsion is adjusted to about 150 to about 10,000 centipoises.
Claims13
A sustained-release microcapsule for injection containing a water-soluble drug, which is produced by a process consisting essentially of preparing a W/O emulsion composed of a water-soluble drug-containing solution as the inner aqueous phase and a biodegradable polymer-containing solution as the oil phase, adjusting the viscosity of the W/O emulsion used in preparing the W/O/W emulsion to from about 150 to about 10,000 centipoises by the procedures of increasing the polymer concentration in the oil phase;
- adjusting the ratio of the aqueous phase to the oil phase;
- adjusting the temperature of said W/O emulsion;
- adjusting the temperature of the external aqueous phase;
- adjusting the temperature of the W/O emulsion with a line heater or cooler or the like in infusing the W/O emulsion into the external aqueous phase;
- or carrying out the above procedures in combination, dispersing said emulsion in an aqueous phase and subjecting the resulting W/O/W emulsion to an in-water drying to form microcapsules.
Dependencies are inferred from the claim text.