Check the instructions on the medicine bottle. Most liquids will require shaking before being drawn into oral medicine syringes. Unscrew the top of the bottle and see if it has a bottle stopper. If so, put the tip of the oral syringe in the hole, while keeping the bottle upright. Once you notice it fits snuggly, turn the bottle upside down carefully and hold the syringe tightly against the bottle at eye level. Pull the plunger back, filling the syringe with a little more than the required dose. Slowly push the plunger up to the correct line for the dose. This helps get rid of any air bubbles that may have been drawn into the oral syringe. You can also tap or flick the barrel of the syringe with your finger to move the air bubbles toward the top of the syringe before pushing the plunger. Turn the bottle back upright, remove the medication syringe, and secure the cap on the bottle.
If the medication bottle doesn't have a stopper, slowly pour a small amount of medication into a measuring cup and insert the tip of the syringe into it. Pull in slightly more than the required dose, turn the oral syringe upwards and push the plunger to remove the unwanted air bubbles.