I guess the Command and the Time trigger are clear. But I don't understand the contact trigger.
What does contact mean? Skin contact, Aura contact, Cloth contact, ...?
How does a magician store his preparation once he created it? Because obviously he's not aloud to touch it or "get in contact". Does he need a drone servant? And what if he wants to throw or place it somewhere? He needs to get it out of his bag/suitcase/whatever without getting in contact so the target can be the one to trigger...
Or does the magician not count as a a trigger? How does he trigger his contact preparations? "Hey, you there, plz come here and touch this. It's some great and of course not dangerous magical thing!"

And seriously, that Fixation metamagic needs some rework. The idea is great, but I'm not gonna pay karma for every spell I use...
It should be

Fixation
Instead of one per hour your preparation now loose one point of potency every (initiate grade) days.

fixed.

Yeah contact leaves a lot to guessing. Break the vial on someone? or just by touch?

Spending a point of Karma to extend the life of a potion is not much different than using the quickening metamagic on a sustained spell. It strengthen the magic. Yes, quickening makes an effect permanent, but preparations have more variety available.

I do agree it should extend the decay rate to either 1 per (initiate grade) days OR 1 per (Karma spent, Max equal to Force of item)days with the latter being more dependent on what you put into it. remember the Karma going in also helps resist someone trying to break it with Disjoining.

In my game, it would be perfectly OK to add one to the drain and let the caster add an additional condition to a trigger or an additional trigger.

So a touch trigger that will only activate if anyone (living creature) touches it besides the caster.

Or a touch trigger that will only activate if it is picked up by a living creature.
Stepping on it won't activate the spell, but picking it up by hand will.
Picking it up with glove will still trigger it since it can still touch the target's aura.
But picking it up with a pair of tongs wouldn't trigger it since it is kept far enough away from the user's aura that no contact is made.

Or a touch trigger that requires that the object be touched by bare flesh. So if wearing shoes or gloves you could step on it or pick it up, but if you remove the gloves and touch it, then it activates.

Or add one drain to combine two triggers.
So only activate if touched by a living creature who says "Oh Frag me".

The general rule is a trigger only has the caster's senses.
Otherwise you need a detect spell added to the ritual.

I'm sure there will be expansions on this in the Magic book.

I'd be careful with using Karma to extend it.

I could see using a preparation as a form of Quicken spell but it should have all the costs and limitations of a Quicken spell.

The Fixation Metamagic already costs Karma to extend the shelf life of the preparation, OP was asking why he had to pay Karma for that and was suggesting an alternative.

I was just comparing it to having pay Karma for quickening.

That would be an interesting expansion on the Touch Trigger to be more specifc at the cost of drain.

Right now Touch trigger is the most open and dangerous of the triggers because it's not controlled by the magician after he's done. It's the magical landmine waiting to go off and it doesn't matter who touches it. as a magical spell, use the:
"Some spells can only be cast on targets that you’re touching. You don’t need to see these targets, but you might need to make an unarmed attack to make contact with an unwilling target. Touching a target through clothing, armor, or a layer of paint is acceptable." If you're like trying to touch/throw the preparation at a target.
Treat a touch attack using the same spell rules, so through clothing, armor or a layer of paint. So like the credstick example being picked up as well as a "Bad" Penny with a fireball spell being stepped on so you know when that group of guards is comming down the hall.