Pharmaceutical companies need to have stability indicating methods in place to be able to detect products of drug instability.
Here are five major degradation pathways:
Damage from an acid can cause loss of structural components necessary to the molecule
Damage from a base can cause loss of structural components necessary to the molecule
Change in number or types of chemical bonds
Exposure to heat can cause a molecule to lose necessary critical functional groups
Light sensitivity can cause molecule to fall apart and become ineffective or toxic
This paper is a comparative analysis between the application of the FDA Process Validation Guidance (2011) to new products and legacy products.