A Guide to Analytical Method Development: Part 1

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?

Development Phase

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!