Stability study design
Stability study design: 6 articles from Peptides Info. Handling, storage and laboratory reference.
Mass Balance in Forced Degradation: Calculation and Shortfalls
The reconciliation a stability-indicating method depends on: the ICH Q1A(R2) definition, the (assay + degradants) ÷ initial formula normalised to the unstressed sample, response-factor and molecular-weight corrections worked for a generic stressed peptide, how the acceptance window follows from precision, and the numbered investigation when degradants are missing.
Accelerated Stability and Arrhenius Extrapolation: What a Hot Study Can and Cannot Predict
The Arrhenius equation, what the activation energy silently assumes, a worked extrapolation from three temperatures, why lyophilised and solution peptides break the model in different ways, and what ICH allows an accelerated result to support.
Designing a Stability Study: The ICH Q1A Framework Scaled to a Small Lab
How stability is established rather than assumed: storage conditions, pull points, attributes, sample numbers and acceptance criteria, taken from ICH Q1A(R2) and the 2025 consolidated Q1 draft and scaled to a laboratory without a stability department.
Forced Degradation: Stressing a Peptide on Purpose to Learn How It Fails
The deliberate-degradation experiment: how it differs from stress and formal stability testing, the conditions used on peptides, the extent of degradation to aim for, identifying the products, mass balance, and why it has to come before a stability-indicating method.
Photostability Testing: ICH Q1B, Light Sources and Amber Glass
How light sensitivity is established rather than assumed: the Q1B exposure units, the Option 1 and Option 2 sources, dark controls and actinometry, the stepwise container sequence, which residues absorb, and what amber glass does and does not stop.
Stability-Indicating Methods: Why a Purity Assay Alone Does Not Qualify
What a method has to demonstrate before its results can support a stability claim: specificity shown with degraded samples, resolution of degradants, an assay that measures amount, closed mass balance, and the validation elements, with a checklist.