alter the sample composition, thereby maintaining data accuracy and integrity.

2. Scope

This procedure applies to all dissolution methods developed in the Analytical Method Development (AMD) department involving filtration of samples prior to analytical measurement.

3. Responsibilities

• Analytical Scientist: Performs compatibility testing with different filter materials and documents recovery data.
• Group Leader: Reviews filter type selection and validation data.
• QA Executive: Verifies compliance and reviews filter validation records.

4. Accountability

The Head of Analytical Method Development is accountable for ensuring appropriate filter compatibility testing is completed and approved prior to method validation.

5. Procedure

5.1 Filter Types for Evaluation

1. Select minimum three different filter types based on availability and compatibility with the dissolution media:
   • 0.45 µm Nylon
   • 0.45 µm PVDF (Polyvinylidene fluoride)
   • 0.45 µm PTFE (Polytetrafluoroethylene)
   • 0.45 µm PES (Polyethersulfone)

5.2 Sample Preparation

1. Prepare drug solution at target concentration (same as expected in dissolution sample) using selected media.
2. Prepare a control sample (unfiltered) and filtered samples using each type of filter under test.
3. Filter at least three replicates through each membrane filter.

5.3 Assay and Recovery Evaluation

1. Analyze filtered and unfiltered samples using a validated method (e.g., UV or HPLC).
2. Calculate the % recovery of filtered samples compared to the unfiltered control:
   
   % Recovery = (Filtered Sample Result / Unfiltered Sample Result) × 100
3. Acceptance Criteria:
   • Recovery should be within 98.0% – 102.0%
   • RSD of replicates should be ≤ 2.0%

5.4 Final Selection and Documentation

1. Select the filter type that meets the recovery and variability criteria.
2. Document filter brand, type, pore size, and lot number in Annexure-1.
3. Include photographic evidence of filter membrane if available.
4. Summarize compatibility results in Annexure-2 and update in the dissolution method SOP.

6. Abbreviations

• SOP: Standard Operating Procedure
• PVDF: Polyvinylidene Fluoride
• PES: Polyethersulfone
• PTFE: Polytetrafluoroethylene
• RSD: Relative Standard Deviation

7. Documents

1. Filter Compatibility Recovery Log – Annexure-1
2. Compatibility Evaluation Summary – Annexure-2
3. Certificate of Analysis (CoA) of Selected Filter – Annexure-3

8. References

• USP General Chapter <1092> – The Dissolution Procedure
• ICH Q2(R1) – Validation of Analytical Procedures
• FDA Guidance on Dissolution Testing

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name	Priya Kulkarni	Sachin Nair	Sunita Reddy
Designation	Analytical Scientist	QA Reviewer	Head – AMD
Department	Analytical Method Development	QA	Analytical Method Development

11. Annexures

Annexure-1: Filter Compatibility Recovery Log

Filter Type	Replicate 1 (%)	Replicate 2 (%)	Replicate 3 (%)	Average Recovery (%)	RSD (%)	Status
PVDF 0.45 µm	99.4	99.1	99.5	99.3	0.2	Pass
Nylon 0.45 µm	97.2	96.9	97.5	97.2	0.3	Fail

Annexure-2: Compatibility Evaluation Summary

PVDF 0.45 µm membrane filter selected for dissolution sample filtration. Recovery within range and consistent across batches. Details updated in the dissolution method validation protocol.

Annexure-3: Certificate of Analysis (CoA)

Attached CoA of PVDF membrane filter from vendor: Merck Millipore, Lot No.: FVM2025-789

Revision History:

Revision Date	Revision No.	Details	Reason	Approved By
21/05/2025	2.0	Expanded to include multiple filter types and quantitative RSD criteria	Annual SOP Review	Sunita Reddy
15/04/2022	1.0	Initial Issue	New SOP	QA Head