Is there an invisible seal on an unopened Levemir pen?

[FurBabiesMama]

Hi. Just like with vials, unopened Levemir FlexTouch pens are supposed to be good until the printed expiration date, but once you open them, they lose effectiveness more quickly. (Obviously, they are fine for longer than the 42 days the manufacturer states, especially since we keep them refrigerated since we don't have to worry about issues with the mechanism. But, they do loose effectiveness sooner than the printed expiration date that is years out.)

I have been wondering why/how that is true. Does anyone know? With a vial, there is a clearly visible seal on the top that must be broken to use it, so I have assumed that is at least a big part of the reason. Is there a seal that gets broken when a pen is first opened that is just not visible to me once I open it? Or, is the brief exposure to light that occurs when the cap is removed for drawing out insulin enough to impact the effectiveness..or the brief exposure to room temperature or just the fact that needles are being stuck in it.. what is it?

 

[Wendy&Neko]

I have used a Lev cartridge for over 90 days, to the last drop. A Lev cartridge, not available in the US, is like a pen refill without the extra packaging of a pen, looks like a mini vial. It has the same type of top as the vial that you out the needle through.

 

[MrWorfMen's Mom]

It's the breaching of the rubber stopper in the vial (cartridge) that allows air and possibly other contaminants into the vial that cause it to deteriorate faster once used than those with the stopper intact, sitting in the fridge. The expiry dates provided by manufacturers are indicative of how long they have tested the product under different conditions but that doesn't mean it's gone bad on the stroke of MN at 42 days or the expiry date on the packaging. Not sure how the pens are packaged but the cartridges we get in Canada are in a bubble type protective wrap. Perhaps the pen itself provides the extra "seal" with the pens.

 

[FurBabiesMama]

I know that the in-use insulin is effective for considerably longer than the 42 days the manufacturer states, but it is not good for years. So, I wanted to understand why an unopened pen is. Thanks for the explanation, Linda.

It's the breaching of the rubber stopper in the vial (cartridge) that allows air and possibly other contaminants into the vial that cause it to deteriorate faster once used than those with the stopper intact, sitting in the fridge

 

[JoyBee&Ravan]

Ravan gets a low dose so his Levemir Pen lasted for almost 4 months. It appeared to be working just fine to the last dose. ( I was trying not to waste any & would often inject the excess I accidentally pulled out back into the pen.)
I'm much better at getting the accurate dose into the syringe now.
I once read it's the same with meds & vitamins. You can safely use it way beyond the expiration date.

 

[Bronx's dad (GA)]

There is no seal on a new Levemir pen.