Don't think so, since SP medigels are more like Ops Packs. All the other ways work fine though.
You can, but it is slightly more annoying since if you are below max health it will use it as the Ops and you have to wait for the medigel animation. It works the same as MP if you are at max health, and your allies are at max health.
Unfortunately the game also has an issue where it sometimes thinks Shepard or your squad isn't actually at full HP when you are, causing you to consume medigel and get nothing in return.
For SP the best method is probably an empty grenade power, you can even potentially use one you add with console or Gibbed, set to Level 0 if you already have it on a quick slot.