Cyclophosphamide can undergo degradation and form impurities when exposed to various stress conditions, such as acid or base hydrolysis, oxidation, and heat.

Cyclophosphamide has a characteristic UV absorption spectrum, which allows it to be detected and quantified using a UV detector. The concentration of Cyclophosphamide and its impurities are determined by comparing the UV absorption of the sample to that of known standards.

The impurities can affect the quality of Cyclophosphamide by reducing its potency, altering its pharmacokinetics or pharmacodynamics, causing unwanted side effects, or even posing a risk to patient safety.

The control of Cyclophosphamide impurities is regulated by various international regulatory bodies such as the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) and the US Food and Drug Administration (FDA).