PURPOSE: To provide the titled donor capable of releasing the drug in a living body under controlled condition, by dissolving chitin in a solvent, contacting the obtained dope with a coagulating liquid to obtain swollen chitin, impregnating the swollen chitin with a drug-containing solution, and drying the product.

CONSTITUTION: Chitin (poly-N-acetyl-D-glucosamine) is dissolved in a solvent (e.g. trichloroacetic acid), and the obtained dope is charged in a pressure tank and extruded with a gear pump, etc. through a sepcific die into a coagulating liquid (e.g. water, alcohol, ketone, etc.) to obtain a swollen product having the form of rod, ring, sheet, etc. The product is impregnated with a solution containing a drug (e.g. proteinous drug, anti-infective, carcinostatic agent, remedy for ophthalmic diseases, etc.), and dried to obtain the objective donor. When the donor is brought ino contact with a body fluid, it releases the drug slowly over a lont time into the body fluid, and finally the donor itself also disappears. The releasing period can be adjusted.