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How to Prepare a Lyophilized Powder for Injection

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A vial of bacteriostatic water for injection, a vial of lyophilized powder and a small syringe are in the foreground. A box of small syringes and a needle-disposal container, or sharps container, are in the background

What Is Lyophilized Powder for Injection?

Some medications that need to be injected into the body are lyophilized, or freeze-dried. Before a lyophilized medication can be administered, it needs to be reconstituted, which is the process of mixing it in bacteriostatic water so that it can be injected. Bacteriostatic water for injection is sterile water that contains a small amount of benzyl alcohol. Below are instructions on how to reconstitute a lyophilized medication.

Items Needed to Prepare a Lyophilized Powder

  • Vial of lyophilized medication
  • Vial of bacteriostatic water for injection
  • Mixing syringe
  • Injection syringe
  • Alcohol wipes
  • Sharps container

A vial of bacteriostatic water for injection, a vial of lyophilized powder and a small syringe are in the foreground. A box of small syringes and a needle-disposal container, or sharps container, are in the background
An alcohol wipe in a small, sealed packet and a large syringe are in the foreground. A box of alcohol wipes and a box of large syringes are in the background

How to Prepare a Lyophilized Powder for Injection

  1. Wash your hands thoroughly and assemble the necessary supplies on a clean surface
    Two hands wash each other in front of a faucet that is on. There are soap bubbles on the hands
  2. Remove the plastic caps from the vials containing the lyophilized medication and bacteriostatic water. Wipe the tops of the vials with alcohol pads and let them dry
    A left hand holds a vial of bacteriostatic water while a right hand rubs the stopper in the top of the vial with an alcohol wipe
  3. Using the provided mixing syringe, tighten the needle to the hub and then pull back the plunger to the volume to be reconstituted
    A right hand holds the hub of a syringe while a left hand pulls back on the plunger to bring air into the barrel
  4. Insert the needle into the bacteriostatic water and push the plunger in
    A left hand holds a vial of bacteriostatic water while a right hand holds a syringe, the needle of which has been inserted into the top of the vial. The first finger of the right hand is pressing down on the plunger of the syringe to inject air into the vial
  5. Turn the vial and syringe upside down and draw out the amount of bacteriostatic water directed on your prescription by slowly pulling the plunger back
    A left hand holds a vial of bacteriostatic water upside down while a right hand holds a syringe, the needle of which has been inserted into the vial. The right hand is also pulling the plunger of the syringe to draw bacteriostatic water from the vial
  6. Remove the needle from the bacteriostatic water vial and insert it into the vial containing the lyophilized medication
    A left hand holds a vial of lyophilized powder while a right hand inserts the needle of a syringe into the top of the vial
  7. Slowly push in the plunger to transfer the bacteriostatic water from the syringe to the vial containing the lyophilized medication
    A left hand holds a vial of lyophilized powder while a right hand holds a syringe, the needle of which has been inserted into the vial. The first finger of the right hand presses down on the syringe plunger to inject bacteriostatic water into the vial
  8. Before removing the needle, draw out a volume of air equal to the volume of liquid that was injected into the vial. This will keep the pressure equal within the vial
    A left hand holds a vial of lyophilized powder and bacteriostatic water while the thumb and first finger of a right hand pull on the plunger of a syringe, the needle of which has been inserted into the vial, to draw excess air from the vial
  9. Swirl the vial until the solution is clear
    A left hand holds a vial of lyophilized powder and bacteriostatic water by its top and swirls it clockwise to mix the powder into the water. Four black arrows form a circle around the bottom of the vial and point in the clockwise direction to indicate the swirling motion
  10. Before inserting the needle of the injection syringe into the vial, wipe the top of the vial with an alcohol pad
    A left hand holds a vial of reconstituted medication while a right hand rubs the stopper in the top of the vial with an alcohol wipe
  11. Obtain a new, unused injection syringe. Bring air into the syringe equal to the volume of medication to be injected by pulling back the plunger, then remove the cap of the syringe
    A left hand holds the base of a small syringe while a right hand pulls down on the plunger to bring air into the syringe
  12. Insert the needle into the vial containing the reconstituted medication. Push the plunger in and then turn the syringe and the vial upside down. Pull back the plunger to draw the prescribed amount of medication into the syringe
    A left hand holds a vial of reconstituted medication upside down while a right holds a small syringe, the needle of which has been inserted into the vial. The right hand is also pulling on the plunger to draw the medication into the syringe
  13. Gently tap or flick the syringe until all bubbles rise to the top
    A left hand holds a vial of reconstituted medication upside down as well as a syringe, the needle of which has been inserted into the vial. A right hand is preparing to flick the syringe so that any air bubbles will rise to the top of the syringe barrel
  14. To expel air bubbles contained within the syringe, remove the needle from the vial and slowly push the plunger until a small drop forms on the tip of the needle
    A left hand holds a syringe loaded with reconstituted medication. The thumb of the left hand has slightly pushed the plunger, and a small drop of the medicine has formed on the tip of the syringe needle. The back of the first finger of a right hand is resting on the barrel of the syringe
  15. Choose an injection site recommended by your physician
    The right side of a human body, both the front and the back. Three areas are highlighted in blue and surrounded by dotted lines: the outer part of the shoulder, the outer part of the mid-thigh and the back of the right hip
  16. Discard the syringes into a sharps container (more information is below)

How to Dispose of Used Syringes

You can purchase a sharps container, which is a hard-plastic container made especially for used syringes and needles, at your local pharmacy. If you did not purchase this container with your medication, you can use a hard-plastic container with a screw-on top, such as a clothing softener bottle or hard-plastic detergent bottle. Make sure you can easily put both the syringe and the needle into the container.
Regardless of which container you choose, make sure that needles cannot break through the sides, bottom or top.
Contact your healthcare provider or your local pharmacy about how to properly dispose of used syringes and needles. You can also visit safeneedledisposal.org.

On the left, a hand places a syringe into a cup-like container that has a biohazard symbol on it. On the right is a laundry detergent bottle with the lid on