What do "USP 26" and "USP 42" mean? I am being asked by a colleague if the Polyvinylpyrrolidone (PVP) we buy in our lab is &quot;USP 26&quot; or &quot;USP 42&quot;. I've never heard those terms before. I searched up online but found nothing.
I'm sure its something concerning the US Pharmacopeia, but I've found their site to be extremely walled up and unhelpful.
Can anyone tell me what do those terms mean, and how to find out if my PVP is either? The manufacturer's Safety data sheet didn't seem to mention it.
Note: I don't work at a food grade or drug grade lab. I'm also not in the USA.
I was able to reach the manufacturer and ask her directly. USPXX is the &quot;edition&quot; of the US Pharmacopeia's &quot;exams&quot; that a product must pass in order to be considered pharmaceutical grade. As time goes on, these exams may get updated and improved. So a higher number USPXX means that a product passed a more recent (and likely, more demanding) USP set of exams.
Therefore, USP 26 is a cheaper PVP, that may not be able to pass the USP 42 standards. Or at least, wasn't tested on them.
On the other hand, USP 42 is a more expensive PVP,  that can and did pass the standard.
As for the actual differences between both standards, I don't know them. So I can't say if the difference between then it's significant or not. It seems USP guidelines are not available freely.
Edit: Todd Minehardt's comment had the right answer it seems.