PROBLEM TO BE SOLVED: To provide a production method of a controlled release system, particularly a method for including a compound in a polymer carrier for controlled release of an active ingredient such as drug, preferably a biologically active ingredient.SOLUTION: By this method, a system for controlled release of an active ingredient, particularly a system for controlled drug delivery is provided. According to the present invention, the term controlled release encompasses various kinds of controlled release including sustained release, extended release and delayed release. In particularly, the present invention provides an active ingredient included in a polymer carrier such as micelle, nanoparticle and microsphere or in a polymeric device or another kind polymer device, or incorporated by another method, or bound to them, for controlled release. The active ingredient is covalently bound to the polymer carrier or the polymeric device.
