| 摘要 |
PURPOSE: To provide a prefilled syringe wherein there exists no possibility of mixing of foreign matters and eluation and enough liq.-and air-tightness exist during storing and good sliding properties of a gasket is provided when it is used. CONSTITUTION: A gasket 23 is formed of a rubbery elastic body and the outer diameter of a part 233 of the rear end is smaller than the inner diameter of a barrel 1 and the front face and the side face except the part 233 with the smaller outer diameter are covered with a plastic thin film 231 with good sliding properties and in addition, the inner diameter of a part 234 on the inlet side of a recessed part 232 for fixing a plunger rod is reduced. In addition, at the first position where the head part 22 of the plunger rod 21 is inserted into this part 234 with a reduced inner diameter, the part 233 with a smaller outer diameter of the gasket 23 is expanded so as to fit tightly this on the inner wall of the barrel 1 and at the second position where the head part 22 of the plunger rod 21 is inserted into the part 235 with a inner diameter being not reduced, the part 233 with the smaller outer diameter of the gasket expanded at the first position is returned to the original outer diameter. |
