I had a similar question with some vials not having a vaccum. I asked the store and they replied
To put your mind at ease: not all vials are vacuum-sealed.
This varies by manufacturer and fill process. Some
lyophilized products are backfilled with an inert gas rather
than sealed under vacuum, so the absence of a vacuum is a
normal characteristic of the fill method and is not an
indicator of degradation or contamination.
another store said
That batch was Nitrogen sealed.
