Comparability

In Japanese quality documents, the state in which a product made before and after a manufacturing change is highly similar in quality, safety and efficacy, with any difference shown to have no adverse impact. The Japanese text of ICH Q5E, issued as an MHLW notice on April 26, 2005, uses the paired term (同等性／同質性) for this concept, and the exercise is called a comparability assessment (同等性評価). Be careful in translation: the same word also means statistical equivalence and appears in bioequivalence. When a Japanese document says two lots are equivalent (同等), ask whether it means comparable under ICH Q5E or statistically equivalent.