Drug distributed in a vial for parenteral administration must be withdrawn carefully to provide the correct dose and to prevent problems later.


Goals of dosing:

(1) delivery of correct dose

(2) prevent contamination of drug left in the vial

(3) prevent development of a pressure difference between the interior of vial and the outside air


Steps for withdrawing a dose from a reconstituted drug vial:

(1) Determine the volume of liquid that needs to be withdrawn to deliver the prescribed dose.

(2) Obtain sterile supplies (alcohol swab, sterile needles, sterile syringe).

(3) Remove the covering over the vial septum and clean the septum with an alcohol swab.

(4) Place a sterile needle on a sterile syringe.

(5) Draw air into the syringe to the volume required for the dose. In an airplane a lower volume is required because of the reduced air pressure. In a pressurized environment a higher volume may be required.

(6) Place the needle through the septum of the drug vial and inject the air into the container.

(7) Invert the bottle so that the bevel of the needle is below the surface of the liquid. If the bevel is at or above the liquid surface air may be drawn into the syringe.

(8) Withdraw a volume of liquid into the syringe that is slightly more than needed for the dose.

(9) Examine the syringe for evidence of bubbles or air. Tap the syringe so that bubbles and air rise towards the needle. Reinject these and the extra liquid into the vial.

(10) Withdraw the needle from the syringe and cap/cover the needle.

(11) Replace the needle on the syringe with a new needle prior to making the injection.

(12) Cover the vial septum to prevent contamination.

(13) The vial should be stored at the recommended temperature.



(1) Do not reuse a syringe or needle.

(2) Do not reinject material into the vial or combine contents of separate vials.

(3) Do not enter a vial without cleaning the septum first.


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