I don't know if this is already posted somewhere. Here are a few comtainers that are easy to find.
1. These droppers are good. I get them at Wallgreens. They are called Sweet Breath. They are .125 floz and weigh about .1 oz on my scale.
nice thing is that it already has edible contents "breath freshiner". I use to use eyedrop bottles but they kind of worry me because of the chemicals. I wouldnt use the Sweet Breath droppers for eyedrops. They tend to retain the mint oils. I had to open up the nipple a bit with a pin for thick fluid like Dave's Insanity Sauce.
2. Mylar zip bag. I use these bags that used to contain GNC Whey Protein. They zip shut and are reasonable water tight. They weigh .55 oz. They have a pleated bottom and will sit up when filled. I don't know the exact volume of the bag.
3. Mouthwash bottle. These are good for alcohol, fule or beverage. The cap is a good shotglass or fule measure. The bottle weighs 2 oz for 16 floz. Not super light but very durable with a built in cup.