NO, it cannot be split. Doing so would affect the dosing release of the drug. You wouldn't want 180 mg. of it all at once, right?
Mrs D already posted this, but I'm doing it again! This is not the only source that clearly states not to split the drug (or crush it).
Mestinon Timespan (pyridostigmine) medical facts from Drugs.com
If the Timespan is more than you need, then why are you taking it? To avoid the waking up every three hours needing more Mestinon (as I have to do)?
None of the Mestinon drugs can be put in a fridge, either. I know that humidity tends to crumble the Mestinon tablets, but putting them in a fridge reduces the potency of the drug.
Are you not doing well?
Annie