I. Core Regulations and Standards of Reference
Compressed air used in the production of injectable preparations is a process gas that comes into direct contact with pharmaceutical products and must comply with the stringent clean‑gas requirements set forth in the Good Manufacturing Practice (GMP) for pharmaceuticals. The primary technical basis includes the General Principles of the Chinese Pharmacopoeia (ChP).9201 Microbiological Limit Test for Pharmaceutical Excipientsand9202 Microbiological Limit Standards for Non-Sterile Pharmaceutical ProductsImplicit control principles for process gases in China; General Principles, Volume IV of the 2020 Edition of the Pharmacopoeia of the People’s Republic of China9101 Guideline for Validation of Analytical Methods for Pharmaceutical Quality StandardsIt covers the requirements for the suitability of gas detection methods, as well as ISO 8573-1:2010, “Compressed air — Part 1: Contaminants and purity classes.”
II. Limit Requirements for Key Indicators
- Oil content: According to ISO 8573-1, compressed air for injectables is typically classified as Class 1 (≤0.01 mg/ m³), with internal control standards for some enterprises being tightened to ≤0.003 mg/ m³; No liquid oil or oil mist shall be detected.
- Moisture content (dew point): According to ISO 8573-1, Class 2 level (pressure dew point ≤− 40℃), ensuring that no condensate forms to prevent microbial growth and system corrosion.
- Suspended particles: In accordance with ISO 8573-1 Class 2 (particles ≥0.5 μm ≤10⁶ per m³) m³; ≥1.0 μm particles ≤ 10⁵ per/ m³), while also meeting Grade A/ ISO Dynamic particle control requirements for downstream gas usage points in a Class 5 cleanroom environment.
- Microorganism: There are no mandatory numerical limits, but GMP requires “not detectable,” meaning that in a 1 m³ sampling volume, it must be achieved.SterileLevel; in practical verification, the airborne microbial method is often employed (≤1 CFU/ m³) and the settling bacteria method (≤1 CFU/4 h·Φ90 mm) Double confirmation.
III. Key Points for Verification and Monitoring
Compressed air systems shall undergo installation qualification (IQ), operational qualification (OQ), and performance qualification (PQ). Critical points of use shall be subject to full‑scope testing at regular intervals, with a frequency of no less than once every six months; additional real‑time testing is required prior to high‑risk processes such as filling and lyophilization. Microbiological testing shall be conducted using dedicated sampling equipment that has been validated for media suitability, and sampling operations must be performed under Grade A laminar airflow within a Grade B cleanroom environment.