Percutaneous medication device and needle formation used for the device

A percutaneous medication device, comprising:

• a syringe to be filled with medical fluid, the syringe including a syringe body with a leading-end through which the medical fluid is dispensed and a movable plunger provided within the syringe body for dispensing the medical fluid;
• and
• a needle formation attached to the leading-end of the syringe body,
• wherein the needle formation comprises a needle formation body having a leading-end surface, a needle projecting from the leading-end surface of the needle formation body, a cover portion covering a leading-end of the needle formation body, and a fixation member configured to fix the needle to the needle formation body,
• wherein the needle is inserted into a through-hole formed at the leading-end of the needle formation body and the needle is fixed to the needle formation body by the fixation member,
• wherein the cover portion comprises a monolithically formed structure that includes (i) a leading-end wall located at a leading-end of the cover portion and having a leading-end wall surface that faces the leading-end surface of the needle formation body, (ii) one or more sidewalls projecting from an outer perimeter of the leading-end wall in a longitudinal direction, and (iii) a step portion projecting beyond the leading-end wall surface of the leading-end wall in the same longitudinal direction as the one or more sidewalls,
• wherein when the leading-end surface of the needle formation body abuts to the step portion to form a space between the leading-end surface of the leading-end wall of the cover portion and the leading-end surface of the needle formation body, at least a portion of the needle projects out of the cover portion through a needle insertion hole formed in the leading-end wall of the cover portion, at least a portion of the fixation member is disposed on the leading-end surface of the needle formation body and is exposed to the space formed between the leading-end surface of the leading-end wall of the cover portion and the leading-end surface of the needle formation body, and the fixation member does not protrude beyond the leading-end surface of the leading-end wall of the cover portion, and
• wherein the needle formation, which comprises the needle formation body, the needle, the cover portion, and the fixation member, is removably attachable to the leading-end of the syringe body as a single assembled unit to enable attachment of the needle formation to the leading-end of the syringe body prior to dispensing the medical fluid.