Allantoin hs been associated with wound healing. The evidence is inferred by the fact that maggots exude it, and maggots are very good at cleaning up septic wounds. It's even a proper recognised medical therapy for bed sores. (How the diet going ?) :D
I've usually gone to lower concentrations than 0.5%, typically 0.1-0.2% not had any problems with recrystallisation. (I know that the data says that 0.5% is soluble, I've found it difficult to get that all into a hot water phase - YMMV)
At 0.5% I did see one very old product have crystals in it. Came in as a glass complaint. The product was at least 3 years old, not seen the problem since
It looks like you're new here. If you want to get involved, click one of these buttons!