So I recently was Black Friday shopping and I came across a serum product consisting of ascorbic acid and alpha arbutin dissolved in propanediol. This was from a fairly reputable retailer and so my question is if anybody has any specific solubility information about propanediol. I found some resources from a manufacturer of this ingredient suggesting that it can dissolve much higher amounts of ascorbic acid than propylene glycol, but again, no specifics. Any information would be really appreciated. I'm curious to know if any other cosmetic actives can be dissolved in propanediol as well.