hdpe plastic bottle paneling

[Debbieeles]

Hello Chemistry gurus.  I have an issue and I hope you can help me.  I have a solid dose product in a 625cc HDPE plastic bottle capped with an induction seal that is experiencing paneling (walls of the bottle are sucked in).  The product was recently changed to include Zinc, Manganese and Copper.  The product also contains Calcium Citrate in high levels.  We have not experienced this issue in the past before changing to this formula and we also pack this formula into smaller bottle sizes which are not experiencing this issue.  The bottle is significantly deformed and due to the vacuum created by the foil liner induction seal it doesn't reform to shape unless you open the seal.  I know there are several effects that could cause this but I am wondering the impact of the added Zinc, Copper and Manganese to the product.  These were introduced at very low levels in the product 5.5mg, 1.15mg and .45mg respectively  per tablet.  There are 280 tablets in the bottle so in total 4.4 g, 3.22g and 1.26g in total.  Would this amount of these minerals be able to absorb so much oxygen in the bottle that it could cause this deformation?

[chenbeier]

If you open one container, how does the product looks like. any changes happend?

[DrP]

Also - just to rule out the simple explanations...   the product wasn't warm when sealed in the bottle was it? Could it be cooling contraction?

 

 

[Debbieeles]

HI Thanks for taking a look at this for me.  The product is made before the packaging so no chance of it being hot.  There were no issues with how the product looked.