The present invention relates to a composition comprising sustained-release fine particles, characterized in that it contains sustained-release fine particles that can be used in quick-disintegrating tablets in the buccal cavity, one or more fillers selected from the group consisting of sugars or sugar alcohols, and one or more binders for quick-disintegrating tablets in the buccal cavity selected from the group consisting of sugars of high moldability and water-soluble polymer substances, and in that the sustained-release fine particles are granulated with filler and binder for quick-disintegrating tablets in the buccal cavity, and a manufacturing method thereof.