Tare the scale and add the hyaluronic acid powders. Mix the powders into the glycerin.
Hyaluronic acid powders can take a while to incorporate into the water and other aqueous ingredients. By mixing it with glycerine first, it is much easier to combine all of the ingredients quickly.
If you don't want to use glycerin (another humectant), you should allow the hyaluronic acid powders to slowly absorb the water overnight and then you can thoroughly mix together the ingredients.