Pharmsteri™ PSTT Series PTFE Cartridge Filter

Overview

The Pharmsteri™ PSTT Series PTFE Cartridge Filter is a sterilizing-grade, hydrophobic membrane filter engineered for critical gas and air filtration in regulated life science and biopharmaceutical manufacturing environments. Based on a symmetric, non-shedding polytetrafluoroethylene (PTFE) membrane thermally bonded to polypropylene support structures—without solvents or adhesives—the PSTT filter delivers consistent, high-integrity performance across repeated steam-in-place (SIP) and autoclave cycles. Its 0.22 µm pore rating is validated per ASTM F838–22 using Brevundimonas diminuta challenge testing, ensuring reliable removal of microorganisms from process gases, vent lines, and sterile compressed air systems. Designed for integration into stainless-steel housings compliant with ASME BPE and ISO 20360 standards, the PSTT series supports both upstream and downstream filtration in single-use and multi-use configurations, meeting stringent requirements for sterile barrier integrity, low extractables, and material biocompatibility.

Key Features

• Sterilizing-grade hydrophobic PTFE membrane with validated 0.22 µm retention, certified per ASTM F838–22
• Solvent-free thermal bonding of membrane to polypropylene support layers—eliminates adhesive-related extractables and delamination risk
• Full USP in vitro cytotoxicity and USP Class VI plastic reactivity compliance for direct contact with pharmaceutical process streams
• Validated integrity test parameters: minimum bubble point ≥1155 mbar (60% IPA/water, 25°C); water intrusion ≤1.4 mL/min (10″, 2620 mbar)
• Robust thermal stability: withstands 25 consecutive SIP cycles at 127°C (30 min, forward/reverse) while maintaining post-sterilization integrity
• Low leachables profile: endotoxin release <0.25 EU/mL; TOC <0.5 mg/L; conductivity ≤1.3 µS/cm after 5 L water rinse (10″ format)
• Non-fiber-shedding design compliant with 21 CFR 210.3(b)(6), suitable for WFI and clean steam applications per USP

Sample Compatibility & Compliance

The PSTT filter is qualified for use with compressed air, nitrogen, CO₂, oxygen, and other process gases in Grade A/B cleanroom environments. All wetted components—including PTFE membrane, polypropylene core, end caps, support cages, and silicone O-rings—meet USP Class VI biological reactivity criteria and EU food contact regulations (EC) No. 1935/2004 and (EU) No. 10/2011. The filter is manufactured under an ISO 13485-certified quality management system and conforms to ISO 9001 requirements. It supports GMP-compliant validation protocols, including pre-use post-sterilization integrity testing (PUPSIT), and is compatible with automated integrity test systems that comply with FDA 21 CFR Part 11 data security and audit trail requirements.

Software & Data Management

While the PSTT cartridge itself is a passive filtration device, its qualification and lifecycle documentation are fully aligned with digital quality systems used in modern biomanufacturing. Batch-specific Certificates of Conformance include full traceability to raw material lots, manufacturing date, integrity test parameters, and sterility assurance data. Integration with electronic batch records (EBRs) and MES platforms is supported via standardized PDF and CSV export formats. All validation reports—including bacterial challenge summaries, extractables profiling, and endotoxin testing—adhere to ALCOA+ principles (Attributable, Legible, Contemporaneous, Original, Accurate, Complete, Consistent, Enduring, Available) for regulatory inspection readiness.

Applications

• Sterile venting of bioreactors, fermenters, and storage tanks
• Final filtration of compressed process gases prior to aseptic filling lines
• Protection of sensitive sensors and analytical instruments from particulate contamination
• Filtering of clean steam condensate return lines in HVAC and utilities systems
• Gas-phase sterilization in lyophilizer chamber backfill and vacuum break applications
• Single-use system (SUS) gas filtration where low adsorption and high chemical resistance are required

FAQ

What regulatory standards does the PSTT filter meet?
It complies with ASTM F838–22, USP ///, ISO 9001/13485, FDA 21 CFR Parts 210/211, and EU food contact regulations.
Can the PSTT filter be used for liquid filtration?
No—it is specifically designed as a hydrophobic gas/air filter. For liquid sterilization, hydrophilic PTFE or PVDF variants are recommended.
How many SIP cycles can the filter endure without integrity loss?
It maintains validated integrity for up to 25 full-cycle SIP treatments at 127°C (30 minutes, forward and reverse flow).
Is bubble point testing sufficient for routine integrity verification?
Yes—bubble point is the primary method specified for hydrophobic filters per USP ; water intrusion testing is also supported for high-pressure applications.
Are Certificates of Conformance provided with each shipment?
Yes—each batch includes a CoC listing lot number, manufacturing date, bubble point specifications, and sterility assurance data.