ICH Q5C - Quality of Biotechnological Products - Stability Testing

What it says

Stability programmes for biotechnological and biological products must account for the greater complexity and lability of these molecules compared to small-molecule products, addressing potency assays, higher-order structure, aggregation and degradation pathways specific to proteins and other large molecules.

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

What it means in practice

• Biological products require stability-indicating methods capable of detecting changes in higher-order structure and biological activity, not just chemical purity, reflecting the reality that a biological molecule's function depends on its three-dimensional structure, not just its chemical composition.
• Potency assay results, demonstrating the product retains its intended biological activity, are a central stability parameter for biological products in a way that has no direct equivalent for most small-molecule products.
• Storage and handling sensitivity for biological products is often materially greater than for small molecules, requiring stability programme design that accounts for freeze-thaw cycles, agitation sensitivity and similar biologic-specific stress factors.

What inspectors look for

• Whether stability-indicating methods for a biological product genuinely assess higher-order structure and potency, not only concentration or chemical purity.
• Whether stress conditions applied during stability and forced degradation studies reflect biologic-specific risks such as agitation, freeze-thaw and light exposure appropriate to the specific molecule.
• Whether potency assay validation supports the assay's ability to detect a genuine loss of biological activity over the product's stability programme.

Related regulations