Demonstrate sampling recovery
Recovery should be demonstrated for sampled contact materials and methods.
CV-REQ-000001
EU GMP Annex 15: Qualification and Validation§ 10.12
TOPIC EXPLORER
Swab Sampling
Direct surface sampling, location selection and material compatibility.
5 connected references
Justify sampling locations
Protocols should identify sampling locations, their rationale and acceptance criteria.
CV-REQ-000006
EU GMP Annex 15: Qualification and Validation§ 10.11
Understand swab compatibility
Sampling materials and extraction solvents can influence analytical results.
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Validation of Cleaning Processes§ Direct surface sampling
Select suitable sampling methods
Sampling should address soluble and insoluble residues appropriately.
CV-REQ-000016
Q7A: Good Manufacturing Practice for APIs§ 12.7 — sampling
Design direct surface sampling
Surface sampling needs a justified, reproducible collection approach.
CV-REQ-000027
Cleaning validation guide (GUI-0028)§ 9.2.1
Practical guidance
PIC/S Publishes PI 006-4: A New Qualification and Validation Recommendation Takes Effect in October
PIC/S has published PI 006-4, the revised Recommendations on Qualification and Validation, superseding the 2007 PI 006-3 and entering into force on 1 October 2026. Cleaning validation now occupies a full chapter, with HBEL-driven scope, explicit limits on visual inspection and a clear position against continued test-until-clean practice.
FDA Challenges a Visual-Only Cleaning Validation Strategy
A 2026 FDA warning letter to Dabur India rejects a shared-equipment cleaning programme that relied exclusively on visual inspection. The objection is narrower than it appears — and it turns on missing quantitative limits, not on visual inspection itself.
What FDA Has Been Citing in Cleaning Validation: The Recurring Themes of 2025–2026
Twelve FDA warning letters issued between 3 December 2024 and 24 July 2026 cite cleaning and cross-contamination control. Read together rather than case by case, they stop looking like twelve incidents and start looking like one audit checklist: worst-case selection, hold times, recovery, MACO justification, visual-only strategies, sampling locations, change control and lifecycle management — in that order of frequency.
Peptide APIs Put Cleaning Limits Under the Microscope: FDA Cites Missing MACO for Semaglutide and Tirzepatide
FDA's 1 May 2026 warning letter to Harbin Jixianglong Biotech found a cleaning procedure that required a toxicity-based carryover limit, and a validation study that established none — with no justification for swab locations and no swab results.
Can a Cleaning Validation Demonstrate Reproducibility If Every Run Samples Somewhere Different?
FDA's Warning Letter 320-26-43 to Cosmetic Manufacturers (Aust) Pty Ltd. states that the firm's cleaning validation protocol 'was not designed to demonstrate reproducibility'. The cause is a design flaw that is easy to copy by accident: each qualification run sampled a different set of locations, so the runs were never replicates of the same measurement.
AI Enters Continued Cleaning Process Verification — but the Statistics Come First
A January 2026 AAPS PharmSciTech paper proposes normalising every residue result to a percentage of its own specification limit, so that cleaning data from different products can finally be pooled, analysed non-parametrically and monitored as a Stage 3 capability index. The statistical argument is the substance; the AI framing is thinner than the title suggests.
Should Cleaning Validation Extend Into the QC Laboratory?
A 2025 DARU Journal of Pharmaceutical Sciences study builds a structured cleaning-validation protocol for QC-lab glassware and stainless-steel equipment, using oxcarbazepine as worst-case API and pairing HPLC residue analysis with conductivity and TOC detergent checks.
Lab, At-Line, Online, In-Line: Where Does TOC Fit?
TOC can live on the QC bench, on the shop floor next to the vessel, or plumbed into the CIP skid. The instrument is the same; the sampling chain — and therefore the meaning of the number — is not.
When MACO Is Not Enough: What the Granules India Warning Letter Really Teaches
The FDA rejected a retrospective MACO argument in a February 2025 warning letter — not because the arithmetic was wrong, but because the cleaning it assumed had not been performed. What cleaning-validation teams can take from it.
Cleaning Validation Meets Waste Treatment: A Study of SGLT-2 Inhibitor Residues
A NIPER-Ahmedabad group pairs a validated RP-HPLC surface-residue method for three SGLT-2 inhibitors with a detoxification strategy for the resulting cleaning waste.
When Shared Equipment Has Never Been Cleaning-Validated: Lessons From an FDA Warning Letter
An FDA Warning Letter to Indian API manufacturer Micro Orgo Chem describes non-dedicated equipment that had never been cleaned under a validated procedure, cleaning SOPs that were not followed, and no evidence that the rinse and swab samples required by the firm's own procedure were ever collected or tested.
ASTM Puts Process Capability on the Cleaning Validation Agenda
ASTM work item WK92658 wants to standardise how cleaning processes are judged capable — one-sided limits, small data sets, non-normal residues and continued verification included. It is the statistical gap E3106 left open.
ASTM Moves Toward Dedicated Guidance for TOC in Cleaning Validation
ASTM Work Item WK92599 would give total organic carbon analysis its own dedicated guidance for swab and rinse samples — and force cleaning programmes to defend recovery and limits, not just concentrations.