All drugs in Shadowrun are available in whatever vector you want to take them. You can inject them, snort them, lick the dots of the paper, use a slap patch, smoke them, use an inhaler, swallow them, etc. Really, it just depends on the character's preference.
That said, most references I've seen regarded tempo involved it being taken through slap patches (think of a nicotine patch except it contains a tempo/dmso cocktail to release the drug into the user's system).