Standard Operating Procedure for Hold Time Studies in Harvest Tanks in Bioreactor Operations for Biosimilars
| Department | Biosimilars |
|---|---|
| SOP No. | SOP/BS/090/2025 |
| Supersedes | SOP/BS/090/2022 |
| Page No. | Page 1 of 11 |
| Issue Date | 04/05/2025 |
| Effective Date | 06/05/2025 |
| Review Date | 04/05/2026 |
1. Purpose
To establish a systematic approach for conducting hold time studies in harvest tanks used during biosimilar production. This ensures harvested material maintains stability, sterility, and identity during defined storage periods prior to downstream processing.
2. Scope
This SOP is applicable to hold time studies of clarified harvest retained in stainless steel or single-use harvest tanks across all biosimilar bioreactor operations within the manufacturing facility.
3. Responsibilities
- Production Team: Execute sampling and monitor hold time intervals as per protocol.
- QC Department: Perform testing for bioburden, pH, osmolality, and product titer at defined time points.
- QA Department: Review study design, oversee compliance, and approve final data summary.
4. Accountability
The Head of Manufacturing is accountable for ensuring that hold time validation
is completed and limits are established before routine production batches are released to downstream processing.
5. Procedure
5.1 Study Design
- Initiate hold time validation prior to commercial production or during process qualification phase.
- Define conditions:
- Storage temperature: 2–8°C or 20–25°C (based on product stability)
- Duration: 0 h, 6 h, 12 h, 24 h, 48 h, 72 h
- Test attributes: pH, bioburden, osmolality, titer
5.2 Sampling Procedure
- Collect 50 mL sample aseptically from harvest tank at each defined time point using sterile sampler.
- Label samples with:
- Time point
- Tank ID
- Batch No.
- Transfer samples to QC under controlled conditions (2–8°C).
5.3 Analytical Testing
- Perform the following tests:
- pH using calibrated pH meter
- Osmolality via freezing point osmometer
- Titer via ELISA or HPLC
- Bioburden as per pharmacopoeial method (≤10 CFU/mL)
- Record results in Annexure-1: Hold Time Study Log.
5.4 Data Review and Acceptance
- Compile all results in data summary sheet and compare with initial (0 h) values.
- Acceptable variation:
- pH ± 0.2 units
- Osmolality ± 5%
- No increase in bioburden
- Titer variation ≤5%
- QA to approve final hold time limit and include it in process BMR.
6. Abbreviations
- CFU: Colony Forming Unit
- QC: Quality Control
- QA: Quality Assurance
- ELISA: Enzyme-Linked Immunosorbent Assay
7. Documents
- Hold Time Study Log – Annexure-1
- Hold Time Validation Summary Report – Annexure-2
8. References
- WHO TRS 1010 – Guidelines on validation
- ICH Q8(R2) – Pharmaceutical Development
9. SOP Version
Version: 2.0
10. Approval Section
| Prepared By | Checked By | Approved By | |
|---|---|---|---|
| Signature | |||
| Date | |||
| Name | |||
| Designation | |||
| Department |
11. Annexures
Annexure-1: Hold Time Study Log
| Time Point | pH | Osmolality (mOsm/kg) | Titer (mg/mL) | Bioburden (CFU/mL) | Remarks | Analyst |
|---|---|---|---|---|---|---|
| 0 h | 7.2 | 280 | 1.45 | 0 | Baseline | Sunita Reddy |
| 24 h | 7.2 | 281 | 1.44 | 0 | Within limits | Sunita Reddy |
Annexure-2: Hold Time Validation Summary Report
To be prepared and reviewed by QA after completion of full data analysis for each new product or manufacturing scale.
Revision History:
| Revision Date | Revision No. | Revision Details | Reason for Revision | Approved By |
|---|---|---|---|---|
| 04/05/2025 | 2.0 | Included multiple time points and expanded test criteria for microbial control | Validation Protocol Update |