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US 7,923,034 B2Granted
Process for producing microparticles
AssigneeSanten Pharmaceutical Co., Ltd.
InventorsKazuhito Yamada, Yasumasa Sasaki, Fumitaka Tasaka, Mitsuaki Kuwano
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AssigneeSanten Pharmaceutical Co., Ltd.
InventorsKazuhito Yamada, Yasumasa Sasaki, Fumitaka Tasaka, Mitsuaki Kuwano
Estimating the term…
An object of the present invention is to provide a solvent which is able to produce microparticles where content of the drug is still high and no initial burst takes place even when a drug having a low solubility in a halogenated hydrocarbon solvent is used. The present invention provides a process for production by a solvent-evaporation microencapsulation method, of microparticles which are composed of biodegradable polymer and contain a drug having a low solubility in a halogenated hydrocarbon, which is characterized in that the drug and the biodegradable polymer are dissolved in a mixed solvent comprising a first solvent: halogenated hydrocarbon, and a second solvent: a water-immiscible organic solvent in which solubility of the above-mentioned drug is 0.3% (w/v) or more.
A process for production, by a solvent-evaporation microencapsulation method, of microparticles which are composed of a biodegradable polymer and contain a steroid agent, wherein the steroid agent and the biodegradable polymer are dissolved in a mixed solvent comprising dichloromethane and a phenylalkyl alcohol, wherein a mixing ratio of the dichloromethane to the phenylalkyl alcohol is 1:1 to 1:10, a particle size of the microparticles is 500 nm to 150 μm and an initial burst of the steroid agent in the microparticles is lower than in microparticles produced using a non-halogenated solvent and phenylalkyl alcohol.
A process for production of microparticles in which a steroid agent and a biodegradable polymer are dissolved in a mixed solvent comprising dichloromethane and a phenylalkyl alcohol to form an oily phase, the oily phase is mixed with an aqueous phase to form an o/w type emulsion and then said mixed solvent is removed to produce the microparticles, wherein a mixing ratio of the dichloromethane and the phenylalkyl alcohol is 1:1 to 1:10, a particle size of the microparticles is 500 nm to 150 μm, and an initial burst of the steroid agent in the microparticles is lower than in microparticles produced using a non-halogenated solvent and phenylalkyl alcohol.
Dependencies are inferred from the claim text.