It is stable and safe.
One of the reasons why vitamin C is so fragile is that it is broken down just by being exposed to oxygen. Glucose (Dextrose) is combined to a fragile part of L-ascorbic acid biotechnologically, resulting in the formation of L-ascorbic acid 2-glucoside (AA-2G).
This made it possible to maintain stability against heat, light, and water.
Since AA-2G is made only from vitamin C and glucose, there is no risk of harm to the body.