
Philo Pharynx |

Let's experiment. Get a stick and start flailing away as if you are fighting a monster. Then have somebody else give you a drink. You can't do it without expending some attention on not drowning and keeping your head still. Chances are most of the potion ends up on your shirt.
I would say it's a standard from each of them. I'd let a feat reduce it to a move action from the drinkee. I'd probably say move (and swift with the feat), if they had two doses in the potion vial and expanded both. This would represent being less careful and spilling lots of liquid magic around.

BishopMcQ |
Age of Worms introduced a character who used Syringes for potions.
As a Standard Action, he can inject himself with a solution similar to a potion. Each syringe holds a single charge of the liquid and the "potions" were stored in removable glass tubes. It intimated that you could inject potions in others including unwilling creatures, likely with a attack roll.
Another possibility would be to create Oils instead of Potions. Applying an oil is a Standard Action which provokes attacks of opportunity. If the target is unconscious it takes a Full Round