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Making liquid medicine for an injection


Sometimes you need to make liquid medicine from powder to give your child an injection (shot). You do this by mixing the powder for the shot with a liquid.

It is important to keep the medicine sterile (germ free) and mix the right amount of liquid with the powder. This article will help you make the liquid medicine for the shot correctly.

Getting ready

Wash your hands with soap and water. Dry them well. See “Do you know … Clean hands.” Clean your work area with an alcohol prep pad or other disinfectant. Then gather your supplies in this area. You will need:

  • The vial (bottle) of powdered medicine you will give as a shot,
  • The vial (bottle) of liquid – This is usually sterile water or saline. Your child’s nurse or the pharmacy will tell you what to use,
  • 2 empty syringes in different sizes – The nurse will tell you what sizes,
  • 2 blunt (not sharp) needles for liquids,
  • One (1) sharp needle – For giving the shot to your child,
  • Alcohol prep pads, and
  • A sharps container – For throwing away needles.

Mixing the medicine for the shot

1. Prepare supplies

Check the medicine label and the prescription label. Make sure they match and all the information is correct. Then follow these steps.

  • Take the plastic caps off the vials of powdered medicine and liquid – Use your thumb to flip the tops up and off. You will see the rubber stoppers. Avoid touching the stoppers.
  • Clean the stoppers with an alcohol pad for 7 seconds. Let them dry by themselves. Do not blow air on them or fan them. Put the vials aside while you get the other items ready.
  • Open the packages with the needles and syringes. Leave them in the package until you are ready to use them.
  • Take the bigger syringe out of the package and put a blunt red needle on it. Carefully pull the cap straight off the needle.

2. Fill the syringe with liquid

  • Hold the larger syringe in one (1) hand. Pull back on the plunger of the syringe to fill it with air. How much you need depends on how much saline or water you need. You need to pull ____ ml of air into the syringe.
  • Put the vial of saline or water on a flat surface. Put the needle straight through the stopper.
  • Push the syringe plunger down so the air goes into the vial. Keep your thumb on the plunger so air does not come back into the syringe. This makes it easier to get the saline or water into the syringe.
  • Hold the syringe and vial of saline or water in your weaker hand. So if you are right-handed, hold them in your left hand. If you are left-handed, hold them in your right. Turn them upside down so the vial is above the syringe.
  • Pull back on the syringe plunger. Saline or water will flow into the syringe. Pull back until you have the right amount. Keep the tip of the needle inside the vial below the level of the liquid. You might need to pull the syringe down to keep the needle in the liquid.
  • Pull the needle completely out of the vial when you have the right amount of saline or water. Then put the needle straight through the stopper of the vial with powder.

3. Add liquid to the powdered medicine for the shot

  • Push the saline or water into the powdered medicine. Keep your thumb on the plunger so liquid does not come up into the syringe. If you are putting saline or water into more than one (1) vial, do the same thing with the second vial.
  • Take the needle out of the vial of powdered medicine. Throw away the needle in your sharps container
  • Gently roll the vial between your palms to mix the medicine well. Roll until all the medicine is dissolved. Do not shake the container.
  • Wipe the rubber stopper with an alcohol prep pad for 7 seconds. Let the stopper dry without blowing air on it.
  • Write the day and time that you mixed the medicine on the label of the vial. You can only use medicine for a certain amount of time after you mix it. So it is important to write down when you mixed it.

Putting the liquid medicine in a syringe for the shot

1. Prepare the syringe

  • Take out the smaller syringe.
  • Open the other blunt needle just enough to attach it to the syringe (keep the rest of the blunt needle in its package).
  • Then, hold your finger on the needle cap inside the package. Pull the syringe and needle straight back without twisting.

The needle cap should stay in the sterile package. This is so you can put the needle cap back on when you change to a sharp needle for giving medicine. Otherwise, you will not be able to use that needle cap when you change needles.

2. Fill the syringe with medicine for the shot

  • Pull back on the syringe plunger to fill the syringe with air. You need ____ ml of air.
  • Put the vial of medicine on a flat surface. Push the needle through the stopper of the medicine vial.
  • Push the syringe plunger down, so it pushes the syringe air into the vial. Keep your thumb on the syringe plunger so air does not come back into the syringe.
  • Turn the vial upside down with the needle still in it. Make sure to keep the tip of the needle below the level of the medicine. You might need to pull the needle back to keep the tip in the medicine.
  • Pull back on the syringe plunger until the right amount of medicine flows into the syringe. Follow the directions your nurse gave you about how much medicine to give. You will adjust it to the right dose before you give your child the shot.
  • Take the needle and syringe out of the medicine vial. Pull the syringe plunger back until you see a small amount of air at the tip of the syringe. This keeps you from pushing any medicine out by accident.
  • You can find more information by reading “Do You Know … Withdrawing Medicine from a Vial.”

3. Change the needle

  • Slide the needle into the needle cap that is still in its package. Hold the needle with one hand and the syringe with the other, and take the needle off the syringe. The blunt needle should stay inside the needle cap that is in the package. Avoid pushing any medicine out when you do this.
  • Put the smaller, sharp needle on the syringe. If you are giving it later, leave the needle cap on. Put the syringe in a clean plastic bag in the refrigerator until time to give the shot.

Giving the shot

  • When you are ready to give the medicine, pull the pink safety cover down out of the way. Pull the needle cap straight off.
  • Push the plunger gently forward so the air bubble at the end is pushed out. Adjust the medicine dose by pushing some medicine out. Do this until you have the amount in the syringe that your child needs.
  • Give your child the medicine. For more information on giving a shot, read “Do you know … How to Give Subcutaneous Injections.”

Throwing away needles

Put the pink safety cover back over the needle. Throw away all the used needles in your sharps container. Read “Do you know … Throwing Away Sharp Objects Safely” to learn more.


Ask your child’s nurse or doctor if you have questions about making liquid medicine for a shot.


This document is not intended to take the place of the care and attention of your personal physician or other professional medical services. Our aim is to promote active participation in your care and treatment by providing information and education. Questions about individual health concerns or specific treatment options should be discussed with your physician.

St. Jude complies with health care-related federal civil rights laws and does not discriminate on the basis of race, color, national origin, age, disability, or sex.

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