Wow, well that answers it. I should have come to you from the very start. Glad to know my assumption was way off.
So if we got a metacresol/M-cresol free insulin it would no longer have that distinct smell? Any idea on that?
Where'd you find that information out? Thanks for the answer!
well the formulation for Humalog, Novolog, and most modern insulins are licensed, must be made exactly the same way every time they are made, and are part of the drug's copyrights. A new formulation would mean new applications to the FDA, new testing, new data, new analysis, new approval. Ordinary drug licenses and approval take many years.
from what I know, metacresol is both a preservative and a absorption modifier for insulin. Both things affect the efficacy and stability of insulin. The reason(s) that these are in there are many - but the purpose is a longer shelf life, and reasonable/predictable/repeatable absorption rates. Its in a family of compounds called aromatic phenols (STINKY) which have a variety of uses.
there is such controversy regarding these preservatives, because if you were to get your hands on pure cresol you would immediately scream "they are putting POISON in our insulin, ya ya ya ya etc" because pure cresol IS poison. It's also a preservative in highly diluted solutions. Pure anything can kill you. Hell, water can kill you in large quantities.
looking for an insulin without phenols? I dunno, nothing out there suggests to me that they SHOULD change insulin formulation, but what the heck do I know. The other thing that crosses my mind is I have been injecting the stuff since '77 and I love it. (naw really - but it has kept me alive 31 years). PS once upon a time I took a type of insulin that had "fish semen" as a an ingredient... I guess diabetes ain't for sissies.
where? well I am a process engineer and I help make a variety of stuff for a big pharma company. I helped build and start up a Gardasil factory last year and I am working on a Varicella (chicken pox) "bulk and purification" factory right now. I did ask around to the big brained people I work with, and I asked the doctors I know (my Dad and my kid brother) but it's no secret what's in Insulin.... haha not even when they add fish semen.