My world is largely based around the production and consumption of 'drugs', chemicals which have physiological affects. Given the variety of drugs in the world, I am looking for alternate ways of consuming them. There are the standard ways, of course: smoking, snorting, suppositories, oral consumption.
I am looking for more 'creative' ways of drug intake, with the reasons for why they must be taken this way.
Ex: eye drops. Reason: the chemical is too potent to be swallowed/dropped on the tongue, so absorbing it through the eyes is slow enough to avoid the negative affects of an overdose which would come from the rapid oral absorption to be used at all.
Ex: skin patches. Reason: the chemical is produced on a certain sort of material as a catalyst and cannot be separated from it after the fact, requiring the use of cutting the material into strips and placing on the skin.