Its only probable cause if they're in plain sight. If you have a pile of baggies full of pills in your front seat you might have a problem. Otherwise, if a police officer sees them, they're probably already searching you. However, I would think if you had little cards in each baggie with drug name, dosage and other assorted information and if you had them in what was clearly a first aid kit, the risk of harassment is pretty low.
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A gentleman should always be able to break his fast in the manner of a gentleman where so ever he may find himself.--Good Omens