We have a sensory evaluation policy. It is completed each morning or at the change over of any products. Ours is based off of smell, taste, and visual aspects. We product no nicotine, no tobacco products though. I would assume ( i try not to assume very often because it makes an ass out of you and me) that it can be tailored to your product though.
You could visually inspect the first bottles off of each line (or however often you want) and look for warped sections/cracks/breaks/etc, perform a hands on inspection -looking for weakness in bottles or strength of bottle, and you could even smell them- should they have a strong melted plastic smell or hardly none at all?
Write it out and tailor it to your program then compare to the guidance provided (if any is provided) or find guidance in a different certification body and go that route so that you can base it off of something so when your audit comes you at least have something to work with. Or just ask the auditing company?