Which syringe size is best for withdrawing 1 ml of radiopharmaceutical from a multi-dose vial?

Choosing the appropriate syringe size for withdrawing 1 ml of radiopharmaceutical from a multi-dose vial requires consideration of both accuracy and the need to minimize dead space in the syringe. A syringe that is too small may not allow sufficient access or withdrawal capability from the vial, while a much larger syringe could introduce unnecessary dead volume, which is not ideal when dealing with radiopharmaceuticals.

A 2.5 ml syringe offers a good compromise as it provides enough volume to comfortably withdraw 1 ml without the complications associated with using a size that's too small. Additionally, the larger barrel of a 2.5 ml syringe is easier to handle, reduces the likelihood of creating negative pressure within the vial, and allows for more precise control during the withdrawal process.

The 1 ml syringe, while accurate for 1 ml withdrawals, has very little excess volume and could lead to difficulty in maneuvering the syringe, especially with a thicker liquid or if bubbles form. The 3 ml and 5 ml syringes, while they could also effectively withdraw 1 ml, would introduce greater dead space, which can lead to more residual radiopharmaceuticals left in the syringe after withdrawal—this can be a concern in terms of dosing accuracy and waste management of