very good question but whos to say they do sterelize em, or maybe they come pre-sterilised as generic needles wud be sterilised cos how wud the manufacturer know whether it was for execution or for medical reasons, these are the things u need to think on
That's a good question and one that you can find the answer to in Volume 11 No. 8 of the Nexus Journal. I shan't spoil it and give you the answer.
in case the person involved in preparing the injection accidentally sticks the needle in themselves... have I just ruined it
But the person sterilising the needles might prick him or herself in the process so no you have not spoiled it.