Liquid insulin monomer for better control

Hi, I have been wondering why JDRF (and other diabetes associations) do not propagate/fund a development of fast-acting insulins that could be used in pumps, without current toxic and hexamer-promoting formation. Do the milions of insulin dependent patients really need to be treated as ignorants? Just to make it more clear, it is not a rocket science to understand- phenol present in all current liquid insulin formulations, added as ‘preservative’, prolongs the duration of insulin action and delays the onset. The question is, why this preservative has been chosen instead of none (sterile solution) or some less toxic. It is well known that is used as a very cheap solvent to separate the protein from bacterial DNA, during the production. But there are other and non cancerogenic solvents.
Insulin is only active in its monomeric form, and presence of phenol propagate formation of slowly absorbed hexamers.
Monomer liquid insulins have been developed and stabilised in the 90’s, but somehow everything ended under the carpet.

lispro and glargine are sterile liquids. sterile liquids, especially in vials where repeated syringe draws are made, where the patients may store in “room temperatures” (pretty much any temperature under 30C) for a month, expose their vials to sunlight, expose their vials to a bit more vibration and jiggling than recommended, and especially with the practice or drawing room air and pushing that air into the vial, may not stay sterile which is a considerable risk to us. the phenol and m-cresol also have properties such as anti-agglomeration, which is important because if those long insulin chains cross-connect, they will not be insulin anymore.

do I like preservatives in insulin? well, no and yes. no for the obvious cytotoxic reasons, and yes for the “life ain’t perfect and so a little protection against cross linking and actual bugs in my insulin is certainly practical” reason. sometimes I gotta take the lesser of 2 evils.


I have no complaints about the sterility of my insulins over the years, so I accept preservatives as a trade-off to avoid much larger issues. It is a necessary component since we are dipping into the same vial several times, at least 4 times for pumpers and dozens of times for MDIers, and alcohol swabs alone cannot prevent everything. In my 33 years of using insulin I have never had an issue.