Lantus pen efficacy after 75 days

[Vicpug]

With our feline on 2 x 1U a day, the 300U Lantus pen should in theory last 150 days. It is stored in the fridge. Reading thru the forum, should it be discarded after 28 days? We are now 75 days into its use. Risky to use it for so long?

 

[Wendy&Neko]

Insulin stored in the fridge can be used up to six months. Might want to read this Sticky Note.
Insulin Care & Syringe Info: Proper Handling, Drawing, Fine Dosing

Only insulin kept out of the fridge lasts a short time.