Prolonged release microcapsule and its production
AssigneeTakeda Chemical Industries, Ltd.
InventorsHiroaki Okada, Yasuaki Ogawa, Takatsuka Yashiki
Life of this patent
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Abstract
A microcapsule produced by preparing a water-in-oil emulsion comprising an inner aqueous layer containing said water-soluble drug and a drug retaining substance therefor and an oil layer containing a polymer substance, then thickening or solidifying said inner aqueous layer to a viscosity of not lower than about 5000 centiposes and finally subjecting the resulting emulsion to in water drying gives prolonged release of water-soluble drug.
Claims9
A prolonged release microcapsule having an average diameter of about 2 to 200.mu.m for injection, which is produced by preparing a water-in-oil emulsion comprising an inner aqueous layer containing a biologically active polypeptide, a drug retaining substance therefor selected from a member of the group consisting of gelatin, albumin, pectin and agar and an oil layer containing a polymer substance of lactic acid-glycolic acid copolymer or lactic acid polymer, then thickening or solidifying said inner aqueous layer to a viscosity of not lower than about 5000 centipoises and finally admixing the resulting emulsion with a third aqueous layer to give a water/oil/water ternary layer emulsion and then desorbing the solvent in the oil layer.
A method for producing a prolonged release microcapsule having an average diameter of about 2 to 200 .mu.m for injection, which comprises preparing a water-in-oil emulsion comprising an inner aqueous layer containing a biologically active polypeptide, a drug retaining substance therefor selected from a member of the group consisting of gelatin, albumin, pectin and agar and an oil layer containing a polymer substance of lactic acid-glycolic acid copolymer or lactic acid polymer, then thickening or solidifying said inner aqueous layer to a viscosity of not lower than about 5000 centipoises and finally admixing the resulting emulsion with a third aqueous layer to give a water/-oil/water ternary layer emulsion and then desorbing the solvent in the oil layer.
Dependencies are inferred from the claim text.