📌 Importance of Differential Pressure in Pharmaceuticals

1. Prevents Cross-Contamination

   • Differential pressure ensures controlled airflow between cleanrooms of different classifications.

   • Positive pressure in cleaner areas prevents entry of dust, microbes, and contaminants from less clean areas.

2. Maintains Cleanroom Classification

   • Controlled pressure differentials are critical to maintain ISO/GMP cleanroom standards (e.g., Grade A, B, C, D).

   • It ensures compliance with regulatory guidelines like EU GMP Annex 1, WHO TRS, and US FDA cGMP.

3. Supports Product Quality & Patient Safety

   • Prevents contamination of critical products like sterile injectables, ophthalmics, and inhalation products.

   • Ensures consistent quality and safety of pharmaceutical dosage forms.

4. Aids in HVAC System Efficiency

   • Properly maintained pressure differentials help HVAC systems function effectively in providing filtered air.

   • Avoids uncontrolled air infiltration or exfiltration.

5. Regulatory Compliance & Documentation

   • Regulators expect validated pressure differentials with alarm systems and regular monitoring.

   • Differential pressure records are part of batch documentation and cleanroom qualification.

6. Critical for Aseptic Processing

   • Positive pressure protects sterile zones.

   • In case of toxic or highly potent products, negative pressure ensures operator safety and prevents product escape.

✅ Typical Pressure Differentials

• Between clean and less clean areas: 10–15 Pa

• Between critical areas and adjacent rooms: as per regulatory guidelines (maintained continuously and alarmed).