Provided are a medicinal composition containing a herbal medicine excellent in storage stability, and a storage stabilizer and a stabilization method for the medicinal composition containing a medicinal composition. The following components (A) and (B): (A) one or more selected from the following components (A-1) to (A-6) (A-1) buckwheat or an extract thereof (A-2) licorice Or an extract thereof (A-3) glycyrrhetinic acid or a salt thereof (A-4) a salamander or an extract thereof (A-5) a horse chestnut seed or an extract thereof (A-6) a red pepper or an extract thereof (B) A pharmaceutical composition comprising loxoprofen or a salt thereof.保存安定性に優れた生薬等含有医薬組成物、並びに生薬等含有医薬組成物の保存安定化剤及び安定化方法の提供。 次の成分(A)及び(B):(A)次の成分(A-1)~(A-6)から選ばれる1種以上 (A-1)オウバク又はその抽出物 (A-2)カンゾウ又はその抽出物 (A-3)グリチルレチン酸又はその塩 (A-4)サンショウ又はその抽出物 (A-5)セイヨウトチノキ種子又はその抽出物 (A-6)トウガラシ又はその抽出物(B)ロキソプロフェン又はその塩を含有する医薬組成物。