Well, prolotherapy is another matter. The purpose is to injure or almost destroy the nerve, to stimulate repair. I fail to see how dextrose on the skin is going to work, unless it is a special transdermal vehicle. Even then, the concentration has to be high, as it is an osmotic working factor. Dextrose will not pass thru normal skin without facilitation.

Your mixture of drugs will be in a special base that carries them thru the skin into the body. If you try to mix glucose into your cream, it may crack the base and cause separation. Concentrated salts do that to creams as a rule. They break the tiny membranes holding the drugs in an emulsion. So then it may separate and not work. You can ask the pharmacist at the compounding pharmacy, to be sure.