ICH Q5D - Derivation and Characterisation of Cell Substrates

What it says

Cell substrates used to manufacture biotechnological and biological products must be derived, established and characterized using scientifically sound procedures, including cell banking systems with defined testing for identity, purity and stability, to provide assurance that the cell substrate will consistently support safe and effective product manufacture.

Paraphrased for plain-language clarity. Always verify against the current published regulation text.

What it means in practice

• The master cell bank and working cell bank system this guideline describes is foundational to biologics manufacturing consistency, since essentially every batch of a biotech product traces back to a qualified cell bank.
• Cell substrate characterization data generated under this guideline typically supports comparability assessments described elsewhere, since any change to the cell substrate itself is one of the most significant changes a biologics manufacturing process can undergo.
• Adventitious agent testing built into cell bank characterization connects this guideline closely to viral safety and contamination control expectations across the broader biologics quality system.

What inspectors look for

• Whether master and working cell bank qualification testing was completed and documented according to the defined characterization program before the cell bank was used in production.
• Whether cell bank stability is monitored over time and whether cells used in production remain within the qualified passage range.
• Whether any change to the cell substrate or cell banking system was evaluated through an appropriate comparability assessment.

Related regulations