Abstract: The invention provides a pharmaceutical composition that can be used for an efficient administration of a water-soluble polymer drug by a method other than injection, and a method for production of the pharmaceutical composition. The pharmaceutical composition contains a small particle comprised of (a) a water-soluble drug and (b) a pharmaceutically acceptable ionic crystalline compound which is solid at room temperature, wherein the ionic crystalline compound is crystallized in the small particle.

Abstract: The invention provides a pharmaceutical composition that can be used for efficient administration of low-molecular weight drugs and polymeric compounds such as peptides and proteins by methods other than injection, as well as a method for producing the composition. The pharmaceutical composition is for transmucosal administration and comprises (a) a drug having a positive or negative charge at a predetermined pH, (b) a pharmaceutically acceptable small particle and (c) a pharmaceutically acceptable surface-coating polymer capable of being electrically charged at the pH, wherein the surface of the small particle is coated by the surface-coating polymer, the drug is immobilized on the surface of the small particle via the surface-coating polymer, and a complex is formed by a noncovalent interaction between the small particle and the surface-coating polymer and a concurrent electrostatic interaction between the surface-coating polymer and the drug.