Subject: How do I keep the oxidation of Vit C powder to a minimum?

I want to use lab grade Vitamin C powder topically, to try to therapeutically
treat various skin conditions. What's the best way to use it on the skin? If I
mix it w/ distilled H2O, will it oxidize instantly, or can I keep it in an
opaque spray container in the fridge for a while? Or should I just add it to
some lotion & apply? How do I keep the oxidation of Vit C powder to a minimum? I
know to expose it to light & air as little as possible,& that it is
water-soluble, but what is the best medium to administer the Vit C?

Re: How do I keep the oxidation of Vit C powder to a minimum?