看到你的數據, 你應該不需要 refill, this med normally one dose is good enough. that's why the direction wrote as "Single dose". You should be informed some kind of drug interaction upon picking up if you are currently on any.
When to refill, it's a very complicate question, based on your private insurance, some TP follows 2/3 policy but ESI need to be done 80% of your med; Also based on what kind of meds, some PRN (use when needed) meds, monthly max. e.g med used 4 Migraine, if Sig(direction): Use as directed or PRN, than monthly Max. will be 12 tabs. It won't allow to be refill with 30 days..... Ask your RP.h for details.
ODB recipients: Do not allow early refill for more than 10 days ( Very strict), Vacation supply based on the quantity on hand, different qty on hand follows different rules. A signed vacation supply document need to be collected and kept in the pharmacy, do not request vacation supply if you are not really on vacation.