The vial is for multiple use.
My uro's instructions included wiping the cap with an alcohol swab each time before use, then letting it sit with a swab on top while prepping the needle.
My pharmacy will package the 10 ml quantity in two 5 ml vials at no extra charge. The intention is really a travel / home vial (just in case it was exposed too long to temperatures out of range, you don't waste the whole lot), but if you don't travel, do it anyway if they offer the service, use one, then the other. Sounds reasonable for less risk, if there really is any.