Early Step by Step Questions to Ask
- Step I: What type of product/analyte is being tested?
- Step II: What is the intended purpose of the method?
- Step III: What type of method should I use?
- Step IV: What components will effect my method?
Step I: Product/Analyte
What type of product/analyte is being tested?
- Small or large molecules (proteins/peptides).
- Raw materials.
- Intermediates/in-process or finished products.
What is the sample composition?
- Sample matrix.
- Target concentration.
Step II: Method Propose
What is the intended purpose of the method?
- Quantitate, detect, identify, purify, characterize.
Will the method be used for:
- Intermediate/release/stability testing.
- Characterization, formulation, or degradation studies.
- Reference standard qualification.
- Potency, excipient, or impurity testing.
Step III: Method Selection
What type of method should I use?
- Compendial: Standardized Methods (United States Pharmacopeia/National Formulary) or FDA recognized procedures. Requires verification.
- Non-compendial: Method which requires full development and validaiton.
- Literature research
Step IV: Method Components
What components will effect my method?
- Instrumentation selection.
- Reagent/solution/diluent selection.
- Reference standard and control selection.
- Instrument and operation parameter set-up.
- System suitability.
- Test sample used.
Establishing conditions, setting operations parameters, and challenging method performance properties must be measured. This is the QUALIFICATION PHASE!