Such cryoprotectants don't exist... yet
Currently, it is not possible for a human to survive being frozen (or a vacuum for that matter). The expanding substances in our bodies ruptures cell walls killing us on a cellular basis. The cryoprotectants you would need will need to be a fictional substance that would fortify human cell walls in a way that allows a human to survive being both frozen and subjected to a vacuum. Because this technology does not exist yet, it means that this drug can take on any form you so choose. When/if anyone ever discovers a workable cryoprotectant, maybe it will be something you can eat, maybe not, but until then, it is writer's choice. Since the drug could come in any form, then any way you could consume anything would be a possible delivery method; so, just make up what ever scenario you find most interesting.