Standard Operating Procedure for Selectivity and Sensitivity Evaluation in BA/BE Method Validation

Department	BA-BE Studies
SOP No.	SOP/BA-BE/180/2025
Supersedes	SOP/BA-BE/180/2022
Page No.	Page 1 of 9
Issue Date	17/04/2025
Effective Date	20/04/2025
Review Date	17/04/2026

1. Purpose

To define a standardized procedure for evaluating the selectivity and sensitivity of analytical methods used in bioavailability/bioequivalence (BA/BE) studies for accurate quantification of analytes in biological matrices.

2. Scope

This SOP applies to all LC-MS/MS methods developed and validated in the bioanalytical laboratory for BA/BE studies to ensure accurate detection of analytes without interference and to establish the lower limit of quantification (LLOQ).

3. Responsibilities

• Analyst: Prepares and analyzes blank and spiked samples from multiple plasma sources.
• Study Supervisor: Reviews data and evaluates method performance for selectivity and sensitivity.
• QA Officer: Ensures compliance of documented procedures with ICH M10 and FDA guidelines.

4. Accountability

The Head of Bioanalytical Operations is accountable for ensuring appropriate validation of selectivity and sensitivity across plasma sources, as part of the regulatory submission dossier.

5. Procedure

5.1 Selectivity Evaluation

1. Obtain blank plasma samples from at least six independent sources, including:
   • Four normal plasma samples
   • One lipemic sample
   • One hemolyzed sample
2. Process blank plasma samples without internal standard or analyte.
3. Process additional samples spiked with analyte at LLOQ concentration and internal standard.
4. Inject all samples using validated LC-MS/MS method.
5. Evaluate chromatograms for interfering peaks at the retention times of analyte and IS.

5.2 Acceptance Criteria for Selectivity

1. Response in blank sample must be less than 20% of the response in LLOQ for analyte and less than 5% for IS.
2. At least 5 out of 6 plasma lots must comply with these criteria.
3. Record results in Annexure-1: Selectivity Evaluation Log.

5.3 Sensitivity Evaluation

1. Prepare and analyze six replicates of LLOQ samples from a single plasma lot.
2. Inject samples along with a fresh calibration curve.
3. Measure signal-to-noise (S/N) ratio and back-calculated concentration for each replicate.
4. Evaluate method capability to detect and quantify the LLOQ accurately.

5.4 Acceptance Criteria for Sensitivity

1. LLOQ response must be at least 5 times the baseline noise.
2. Precision (%CV) should be ≤20% and accuracy within ±20% of nominal.
3. Document S/N ratios and replicate results in Annexure-2: Sensitivity Evaluation Summary.

5.5 Documentation and Reporting

1. Compile chromatograms, response tables, %CV and %Nominal values for all replicates.
2. Prepare validation summary including selectivity and sensitivity conclusions.
3. Submit report to QA for approval and file with method validation documents.

6. Abbreviations

• BA/BE: Bioavailability/Bioequivalence
• LC-MS/MS: Liquid Chromatography with Tandem Mass Spectrometry
• IS: Internal Standard
• LLOQ: Lower Limit of Quantification
• %CV: Percent Coefficient of Variation

7. Documents

1. Selectivity Evaluation Log – Annexure-1
2. Sensitivity Evaluation Summary – Annexure-2

8. References

• ICH M10: Bioanalytical Method Validation
• US FDA Guidance for Industry: Bioanalytical Method Validation (2022)
• Internal Method Validation SOP

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name
Designation
Department

11. Annexures

Annexure-1: Selectivity Evaluation Log

Plasma Lot	Type	Analyte Response in Blank	% of LLOQ Response	Status
PL-101	Normal	150	12%	Accepted
PL-106	Hemolyzed	240	18%	Accepted

Annexure-2: Sensitivity Evaluation Summary

Replicate No.	Measured Conc. (ng/mL)	% Nominal	S/N Ratio	Status
1	4.8	96%	6.5	Accepted
2	5.2	104%	7.0	Accepted

Revision History:

Revision Date	Revision No.	Details	Reason	Approved By
01/01/2022	1.0	Initial Issue	New SOP	QA Head
17/04/2025	2.0	Updated plasma lot requirements, annexures added	ICH M10 Update	QA Head