I would suggest you use the FDA's NDC lookup site linked here
NDC look up tool. The benefit of using it is that it will not only tell you if a specific NDC is a single use vial, if you search by drug name it will show you the NDCs for various vial sizes so you can ensure you are purchasing the vials sizes that are most appropriate for your practice's general treatment protocols for a given drug. Here is an example of what you would see for Veklury which is packaged in single use vials.
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Another benefit to using the FDA's NDC lookup site is that it is the official source for the information on drugs. I'm not trying to dismiss
@Tourist95's recommended website; however, as someone who has worked in Payment Integrity auditing drug waste claims for an insurance company, I can tell you that we go to the official regulatory source of information regarding drugs, i.e. the FDA.
Another benefit of using this website is that you can click on the drug name in the first column it will link you to the packaging insert for the drug, which will typically tell you how the drug is packaged.
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