If you are that busy, where you need an assembly-line... You might want to research a bottler company. You provide the
juice, and they fill and label the bottles for you. Cheaper than you could do it alone.
If you are not dealing in volumes that high, then it would be cheaper to do it yourself.
Usually, in an assembly line... they would use a box-shape, and have 10 x 10 or something similar. Filling all 100 pre-labeled bottles in one shot, or row by row.
They use a valved and metered plunger style filler, which fills to within 0.1ml to 0.0001ml accuracy. Not sure where you could get one of those, but a standard syringe and stopper-limit for filling would be your best alternative.
Remember to store the bottles in a cool and dark place. Light and heat destroys nicotine and many flavorings. It also promotes bacterial growth. (That is why they sell most in dark glass bottles.)
Invest in a micro-filter to pre-filter the fluids before you use them to fill another device, and a hepa-filter for the area where you are working. The more lab-like your setup is, the less chance you have of causing problems down the line.
You may also want to print-up a full list of ingredients, and the supplier responsible for creating the actual juice. Since you are now redistributing a chemical with a broken seal, you are fully liable for anything that happens to the people you sell this to. It is not the manufactures liability. (You would have to sue them, after you have been sued for distributing a broken-seal bottle. They are only responsible for the bottle without the broken seal, and only if it harmed you, not your customers.)
Just be careful, is all I am saying... If the FDA and the supreme court does find an issue with these things... You would now legally be considered a drug-dealer. (Selling a regulated substance without permission. Though, it would not be as bad as selling a regulated narcotic.)
