This is a ready-to-use log recording growth promotion, the media sterility check, and pH for each lot of FTM and SCDM before it is used in the sterility test. Growth promotion is a release gate: no pass, no use. It is also a recurring inspection finding when a lot is used before results are available or a received lot is never tested. Replace every <<FILL: ...>> placeholder, keep one row per medium lot, and maintain the log under document control. A field-definition table, the blank log, instructions, retention, and a filled specimen follow. The compendial chapter is copyrighted; this log describes the test in original wording and cites the chapter by number. This is general guidance to adapt, not legal or regulatory advice. This log supports the SOP: Sterility Testing (USP <71>).
Field definitions
| Field | Format | Required | Who enters | Definition |
|---|---|---|---|---|
| Medium / lot | Text | Yes | Analyst | FTM or SCDM and the lot number (in-house or vendor). |
| Received / prepared date | Date | Yes | Analyst | When the lot was received or prepared. |
| Expiry / use-by | Date | Yes | Analyst | Lot expiry or established use-by. |
| pH | Number | Yes | Analyst | Measured pH within the medium’s specification. |
| Sterility check (7 day) | Pass / Fail | Yes | Analyst | Uninoculated medium incubated, must show no growth. |
| GPT organisms | Text | Yes | Analyst | The challenge organisms for that medium (<=100 CFU each). |
| Growth by day | Pass / Fail + day | Yes | Analyst | Clearly visible growth within the read window. |
| Overall GPT | Pass / Fail | Yes | Analyst | Overall growth promotion result. |
| Released for use | Yes / No | Yes | Reviewer | Whether the lot is released (only after all pass). |
| Analyst / reviewer | Name, date | Yes | Both | Performer and reviewer sign-off. |
Blank log
| Medium / lot | Received/prepared | Expiry | pH | Sterility check | GPT organisms | Growth by day | Overall GPT | Released | Analyst / reviewer |
|---|---|---|---|---|---|---|---|---|---|
<<FILL>> | <<FILL>> | <<FILL>> | <<FILL>> | <<FILL: Pass/Fail>> | <<FILL>> | <<FILL>> | <<FILL: Pass/Fail>> | <<FILL: Yes/No>> | <<FILL>> |
<<FILL>> | <<FILL>> | <<FILL>> | <<FILL>> | <<FILL>> | <<FILL>> | <<FILL>> | <<FILL>> | <<FILL>> | <<FILL>> |
Instructions
- Test every lot of every medium before use: FTM challenged with the aerobes plus the anaerobe Clostridium sporogenes; SCDM challenged with the aerobes plus the yeast and the mold. Use not more than 100 CFU of each organism.
- Confirm clearly visible growth within the read window (not more than 3 days for bacteria, not more than 5 days for fungi).
- Run the medium sterility check (uninoculated) in parallel; it must show no growth, proving the medium was not contaminated in preparation.
- Do not release a lot for use until pH, the sterility check, and all GPT organisms pass. Never use a lot while results are pending.
- For FTM, reject or regenerate a lot in which more than the upper third is oxidized (pink); regenerate at most once.
Retention
Retain the GPT log under document control for not less than <<FILL: retention period, at least the retention of the sterility results it supports>>. It is the evidence that every sterility result was read on media proven able to grow a low inoculum.
Filled specimen
| Medium / lot | Received/prepared | Expiry | pH | Sterility check | GPT organisms | Growth by day | Overall GPT | Released | Analyst / reviewer |
|---|---|---|---|---|---|---|---|---|---|
| FTM lot F-2606-14 | 02 Jul 2026 | 01 Oct 2026 | 7.1 | Pass (no growth, 7 d) | S. aureus, P. aeruginosa, B. subtilis, C. sporogenes | Pass, day 2-3 | Pass | Yes | S. Rahman / T. Alvarez |
| SCDM lot S-2606-22 | 02 Jul 2026 | 01 Oct 2026 | 7.3 | Pass (no growth, 7 d) | S. aureus, P. aeruginosa, B. subtilis, C. albicans, A. brasiliensis | Pass, day 2 (bact), day 4 (mold) | Pass | Yes | S. Rahman / T. Alvarez |
| FTM lot F-2606-15 | 09 Jul 2026 | 08 Oct 2026 | 7.0 | Pass | full panel | C. sporogenes no growth day 3 | Fail | No | S. Rahman / T. Alvarez |
The third row shows the log doing its job: an FTM lot in which the anaerobe failed to grow was not released, so it never reached a product test where it could have masked a real contaminant. The failed lot is recorded, investigated, and quarantined, not quietly reused.
Common inspection findings this log prevents
- A media lot used in a sterility test before growth promotion results were available.
- A received ready-to-use lot never tested for growth promotion.
- Over-oxidized FTM used without regeneration.
- No medium sterility check, so contamination introduced in preparation could be mistaken for a product positive.
How to adapt this log
- Align the medium specifications and pH ranges to your media certificates.
- Set your organism source and suspension standardization references.
- Add a lot-quarantine column if you hold received lots pending GPT.
- Confirm the challenge organisms and read windows against the current USP <71> before issue.