PREPARATION OF MICROSPHERE

• Main Authors: YAMAKAWA ICHIRO, MACHIDA RYOICHI, WATANABE SUMIO
• Format: Patent
• Language: English
• Published: 17.02.1992
• Subjects: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; HUMAN NECESSITIES; HYGIENE; MEDICAL OR VETERINARY SCIENCE; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; PREPARATIONS FOR MEDICAL, DENTAL, OR TOILET PURPOSES; THEIR RELEVANT APPARATUS; TRANSPORTING

PURPOSE:To heighten the content of a drug ingredient by specifying the solvent composition of an oil phase in a specific combination when the water-soluble drug ingredient is formed into microspheres by an O/W type drying method. CONSTITUTION:A water-soluble drug ingredient is dissolved or dispersed together with a polymeric substance (e.g. polylactic acid, collagen) in an organic solvent composition comprising at least one water-insoluble solvent such as methylene chloride, chloroform or ethyl acetate and at least one water-miscible solvent such as methanol, ethanol, ethanol or dimethyl sulfoxide to form an oil phase (inner phase). The oil phase is added to and stirred in a water phase (outer phase) comprising an aqueous solution containing a active agent such as polyvinyl alcohol to dry in the liquid, thereby providing microspheres containing the water-soluble drug ingredient. The water-miscible solvent is preferably added in a ratio of 5-95%, preferably 10-50%, in the oil phase. The addition of a fatty acid salt to the oil phase heightens the content of the water-miscible drug ingredient.