Prolonged release microcapsule of a water-soluble drug
AssigneeTakeda Chemical Industries, Ltd.
InventorsHiroaki Okada, Yasuaki Ogawa, Takatsuka Yashiki
Life of this patent
Estimating the term…
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.
Claims8
An injectable preparation comprising a therapeutically effective amount of spherical microcapsules and a pharmaceutically acceptable vehicle, wherein said spherical microcapsules have an average diameter of 2-200 .mu.m, and comprise particles of a mixture of a water-soluble non-polypeptidic drug and a drug-retaining substance therefor selected from the group consisting of gelatin, albumin, pectin and agar, the weight ratio of the drug-retaining substance to the water-soluble non-polypeptidic drug being in the range of about 9/1 to about 0.3/1, the particles being dispersed in a spherical microcapsule matrix composed of a biodegradable polymer, said biodegradable polymer being a copolymer of lactic acid and glycolic acid having a comonomer ratio within the range of about 100/0 to 50/50 and an average molecular weight within the range of about 5,000 to 200,000.
Dependencies are inferred from the claim text.