I haven’t used an eye dropper in ages but needed one to draw off the liquid in a homemade tincture. I ordered a glass bottle and dropper of the desired capacity. As soon as I started to use it I am reminded of how frustrating it can be. Try as I might I can only draw the pipette maybe half full. And yet they are sold by the bottle capacity and the calibrated rating of the pipette. The squeeze bulb is just too small.
Searching around I can find others with longer bulbs and even some with bellows that appear they might do a better job. But most of them are the old version that cannot deliver a full pipette worth of stuff. I mean, how much can it cost to make a longer rubber bulb?
Do two half-droppers to get the full dose. Or you could try tipping the bottle a little bit, sometimes that works to increase the amount the dropper will pick up.
In other words, try everything and make do. I use CBD drops, and I go through the same hassle. I don’t think dropper bulb size is a problem that will be addressed any time in the near future.
Is the air in the tube the reason that the pipette doesn’t fill completely? What I’ve done is to squeeze the bulb in the water, so the air is forced out and the resulting vacuum allows for more liquid to be drawn.
In this case I am drawing an ounce of liquid off the unwanted sediment. I have to squeeze at least 30 times to get it all. I have tried various ways to draw more liquid but nada. They do make ones with large bulbs that probably work better but you would think they would all have larger bulbs. I like these bellows types:
Perhaps you should try the hypodermic syringe device and perhaps add a small tube to get into the bottle. These are available typically to dispense antibiotics to children orally. They have a larger capacity. Available from chemist/pharmacy stores.