Another handy item I’ve just acquired from Ebay is these nice little 50ml airless pump bottles.  I plan on using them initially for toiletry items like shampoo, shower gel and shaving gel.  They could come in useful as food liquid storage bottles as well as they are polypropylene so are food safe. The dimensions are 48mm diameter and 94mm high and they are airless. They operate instead by drawing up the bottom of the bottle each time they are pumped.  They are re-usable simply by pushing the bottom back down again.

I think they are ideal storage items for any liquids for a GHB or just for general travel use.