APT200/S+ Automatic Penetration Force Tester

USP 381 is a United States Pharmacopeia general chapter that defines the test methods and acceptance criteria for elastomeric closures (rubber stoppers) used in injectable pharmaceutical packaging. Penetrability testing under USP 381 measures the force required for a standard needle to pierce the rubber stopper — verifying that the closure does not resist needle insertion to a degree that would compromise the ability of healthcare workers to prepare or administer injectable products. Compliance with USP 381 is required for rubber stopper qualification by pharmaceutical manufacturers seeking FDA approval for injectable drug products packaged in vials with rubber closures.

The APT200/S+ provides stepless speed regulation from 0 to 1500 mm/min, controlled through the touch screen interface. Speed is maintained by the PLC and servo drive combination, which delivers consistent motion at the set point regardless of the load variation encountered during needle penetration. Stepless regulation means the operator can dial in the exact speed specified by the test method — for example, USP 381 specifies a penetration speed of approximately 300 mm/min — rather than selecting from a fixed set of discrete speed options. This precision in speed setting is essential for obtaining reproducible penetration force values that can be reliably compared across batches and instruments.

The standard package with the APT200/S+ includes: a needle holder; a vial holder for securing the rubber-capped vial during the test; a starter set of 100 standard needles (0.8 mm diameter, 21G gauge) as specified for the USP 381 penetrability test; full IQ, OQ, and PQ qualification documentation; an operational manual; and a factory calibration certificate. This means the instrument arrives ready for immediate use and formal qualification without requiring the laboratory to source accessories or documentation separately. The 21 CFR Part 11 compliance software is available as a separately specified option.

21 CFR Part 11 is the FDA regulation that governs the use of electronic records and electronic signatures in regulated industries. It requires that computerised systems managing electronic records implement controls including audit trails, user access management, system validation, and electronic signature functionality equivalent to handwritten signatures. For pharmaceutical QC laboratories, operating software that is 21 CFR Part 11 compliant is increasingly required by both internal quality systems and FDA inspection expectations. The optional compliance software for the APT200/S+ provides these controls, enabling the instrument's test data to form part of an auditable electronic batch record without requiring paper printouts and manual signatures.

The PLC (Programmable Logic Controller) provides precise, software-controlled sequencing of the test cycle — including crosshead start, travel, stop, and return — with no reliance on manual timing or operator reaction. The servo drive maintains the commanded crosshead speed accurately using closed-loop feedback, meaning that as the penetration resistance of the rubber stopper varies during the test, the drive compensates to keep the speed constant. This combination eliminates the speed fluctuations caused by load-dependent deceleration that affect simpler motor-drive systems, and ensures that the force–displacement curve recorded during the test is a true representation of the sample's penetrability characteristics at the specified test speed.

The APT200/S+ provides two data output interfaces: USB and Ethernet. The USB port supports both data transfer to a PC or memory device and direct connection of a printer — enabling hard-copy test reports to be printed without a PC intermediary. The Ethernet port allows the instrument to be connected to a laboratory network for direct data transfer to a server or LIMS system. The touch screen interface displays the force–displacement curve and test result in real time, and results can be stored on the instrument and exported at the end of the test session. The optional 21 CFR Part 11 software extends these capabilities with full electronic records management.

The APT200/S+ operates on 220V or 110V at 50/60Hz — the dual-voltage design makes it suitable for use in laboratories worldwide without requiring a transformer. The instrument weighs 45 kg and has a footprint of 450mm × 450mm (L × W) with a height of 1080mm, making it a compact floor-standing unit that fits comfortably in most pharmaceutical QC laboratory spaces. No compressed air or special utilities are required. The compact and stable frame design means the instrument does not require anti-vibration mounting in normal laboratory conditions, though it should be positioned away from heavy machinery that generates significant floor vibration.