I'm sure this has already been covered someWHERE on the site so forgive the duplication.
Stable packaging is a big concern with anti-oxident ingredients in skin care poducts.  Can anyone tell me what happens to those products that are packaged in jars?  Paula Begoun says this is a BIG NO/NO because of the efficacy of the products are compromised by exposure to light and air. 
My question is how SOON do the ingredients degrade and become ineffective.  My specific example would be my Olay Age-Defying Anti-Wrinkle Replenishing Night Cream which is rated HIGHLY by Begoun for its ingredients but then DOWNGRADED because of unstable packaging.
HELP, PLEASE, I am going to try this again since the Forum seems more active these days. 
Is any one else out there aware/knowledgable on this.  It is difficult to avoid JARS but I sure don't need to be buying products that may be well-formulated but lose their potency once the jar is exposed to the air.