The physiologically active substance release layer comprises a biological, physiologically active substance and a flexible biodegradable polymer.

As the physiologically active substance, use can be made of a physiologically active peptide.

Disclosed is a protecting agent for preventing the deterioration of a physiologically active substance during the lyophilization of a mixture of the physiologically active substance and water.

The method enables to microencapsulate a solid physiologically active substance in a predetermined thickness and a predetermined particle size without the need of dissolving the physiologically active substance in any solvent.

Disclosed are: a target protein and a target gene for a physiologically active substance such as a medicinal agent; and a means for developing a novel physiologically active substance by using the target protein or the target gene.

It is intended to provide a target protein and a target gene of a physiologically active substance such as a drug and a means whereby a novel physiologically active substance can be developed by using the same.

It is intended to provide a method which comprises administering a physiologically active substance to a target submucosal tissue and thus fixing and expressing the physiologically active substance specifically to the tissue.

In particular, a method of introducing a physiologically active substance in cells, comprising adhering a physiologically active substance around a needle of 50 to 500 nm diameter in an amount incorporated in cell and inserting the needle into the cell.

In this manner, the measurement of the specific physiologically active substance can be carried out.

Disclosed is a target protein or target gene of a physiologically active substance such as a drug.

The substance is fine particles of a physiologically active substance which have been obtained by the process and contain no dispersants.

A liposome composition effective in administering a physiologically active substance to Peyer's glands.

It is furthermore intended to provide a method for treating a subject by supplying a cell-associated physiologically active substance and a method of preparing the cell-associated physiologically active substance to be used therein.

A microcapsule comprising a physiologically active substance which is water-soluble at a pH no higher than about 3, and a biodegradable polymer.

It enables the physiologically active substance to have improved releasability in the intestinal tract.