VHP in Pharmaceutical Isolators: What Annex 1, FDA Warning Letters, and 21 CFR 211.113(b) Are Actually Requiring

Two FDA warning letters — Catalent Indiana (November 2025) and Simtra BioPharma (March 2026) — both cite VHP decontamination failures in pharmaceutical isolators and RABS. The findings reveal what FDA inspectors are now specifically scrutinizing, and what site-specific VHP validation must actually demonstrate.