[Object]An object of the present invention is to provide a method for producing a microcapsule formulation using a biodegradable polymer, the method being capable of avoiding direct contact of a peptidic physiologically active substance with an organic solvent layer, and achieving a high encapsulation efficiency of the peptidic physiologically active substance.[Method for Achieving the Object]The present invention provides a method for producing a microcapsule formulation comprising: step A of adding a basic amino acid to an aqueous solvent containing a heavy metal salt of a peptidic physiologically active substance to obtain an amino acid-containing S/W suspension step B of adding a basic amino acid to an organic solvent containing a biodegradable polymer to obtain an amino acid-containing polymer solution step C of dispersing the amino acid-containing S/W suspension in the amino acid-containing polymer solution, which is an oil phase, to obtain an S/W/O emulsion step D of dispersing the S/W/O emulsion in a water phase to obtain an S/W/O/W emulsion and step E of removing the organic solvent from the S/W/O/W emulsion.本發明課題在於提供一種胜肽性生理活性物質之封入效率高的微膠囊製劑之製造方法,其係使用了可避免胜肽性生理活性物質直接與有機溶劑層接觸的活體內分解性聚合物。本發明之解決手段是一種微膠囊製劑之製造方法,其含有下述步驟:步驟A:於含有胜肽性生理活性物質之重金屬鹽的水系溶劑中添加鹼性胺基酸,獲得含有胺基酸之S/W型懸浮液;步驟B:於含有活體內分解性聚合物之有機溶劑中添加鹼性胺基酸,獲得含有胺基酸之聚合物溶液;步驟C:將前述含有胺基酸之S/W型懸浮液分散於前述含有胺基酸之聚合物溶液亦即油相中,獲得S/W/O型乳化液;步驟D:將前述S/W/O型乳化液分散於水相中,獲得S/W/O/W型乳化液;及步驟E:去除前述S/W/O/W型乳化液中的有機溶劑。
