PTWS 620

The Magnificent Six. All Six Stations in One Line for Optimal Visibility.

PTWS 620

USP/EP Tablet Dissolution Testing Instrument

The PTWS 620 is a 6 + 2 position, single drive tablet dissolution testing instrument for solid dosage forms as described in USP chapter <711/724> and EP section<2.9.3/4> as well as the DAB/BP and Japanese Pharmacopeia section <15>. The USP monograph <1092/2.4.2> lists visual observation of the dissolution behavior as essential for identifying variables in the formulation or manufacturing process. The six vessels in the front row of PTWS 620 offer optimal visibility of the samples.

PTWS 620 dissolution tester - the 6 main test vessels are arranged in a single line for optimal visibility

PTWS 620 dissolution tester - the 6 main test vessels are arranged in a single line for optimal visibility

User Interface

In keeping with our cutting edge design, a large color, touch screen allows control of the various mechanical features of the instrument such as the tool stirring speed, lift drive and heater. The instrument control is menu driven. Status messages and color changes on the display inform the user of the status of critical instrument parameters, e.g. bath target temperature not reached.

A status bar provides a quick overview and uses the familiar traffic light system green – yellow – red. Access to the instrument can be password controlled if required. If certain operational parameters form a regular feature of the daily routine, then these can be incorporated into a test method for faster set up. These parameters can be tool speed, target bath temperature, sampling time points and so on. The test method memory capacity is almost limitless. As soon as the test is started, a screen saver can be activated with the most important information displayed in large script so that this information remains visible even at time when the operator is not standing directly in front of the instrument.

The instrument is controlled by a color touch screen and an additional keyboard
The MonoShaft™ system enable tool change without requiring a subsequent immersion depth re-qualification
The EPE automated sampling manifold drives into the test vessel at programmable intervals

The instrument is controlled by a color touch screen and an additional keyboard

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Stirring Tools

The PTWS 620 uses the Pharma Test MonoShaft™ design. Tools consist of the main shaft plus interchangeable tool heads (adapters). The main shaft remains in place in the instrument regardless of the tool head being used. The clearance of each tool from the vessel base will always be correct once the main tool shaft has been installed and fixed in its position. A wide variety of different stirring tools is available while the standard configuration includes USP/EP App. 2 Paddle stirrers.

Vessel Centering System

The PTWS 620 features a three-point individual centering system for each dissolution vessel (picture shows view from below). The vessels are held in position by three adjustable noses and are inserted into the instrument support framework. Each vessel is correctly centered against the stirring tool, while this position is secured even when the vessels are removed for cleaning and placed back afterwards. The access points for sampling as well as the openings for the tools are contained in an auxiliary, low evaporation, vessel cover.

Baskets attached to the PTWS 620

Baskets attached to the PTWS 620

Heating System

The ultra-fast heating system is installed on an easy to remove platform within the stainless steel housing. The heat up time of the water bath has been reduced by approx. 40% compared to previous models. Access to pump, heater and all safety sensor system is possible without to move the bath from its qualified position. The connections between the heater and the bath are made by “quick connect fittings” for easy connection and disconnection.

Water is pumped through the system using a powerful, yet quiet, circulation pump. The pump itself is spring mounted (to limit vibration transmission) and the flow-through heater is protected from overloading (overheating in case of control electronics failure) via a thermal fuse as well as a thermo switch for added security. With service and maintenance in mind, access to the compact pump and heater section is easily achieved without having to move the main body of the instrument.

Water Bath

The U-shaped water bath rests on vibration absorbers to avoid any vibration transfer from either inside or outside the instrument to satisfy the requirements from USP <711>.  The water bath contains a water diffuser for faster heating and evenly distribution throughout the whole bath.

Automation Capabilities

The motorized EPE-620 sampling system lowers the sampling probes into the media and after sampling raises them back out again. 8 different sampling positions can be programmed. The ITM-620 individual media temperature monitoring system is attached to the EPE-620 and will read and report the vessel media temperatures while sampling.

The manual TM-620 or motorized TMA-620 tablet dropping magazine completes the set of useful accessories for automation. It covers all vessels and ensures low evaporation rates during the dissolution test. The magazines include magnetic holders for the tube cleaning device.

Offline Sampling and Sample Preparation

For offline automation with fraction collection the PTFC-2/8 fraction collector as well as either a PT-SP8 multiple syringe pump, an IPC peristaltic pump, or a CAT piston pump can be added to the PTWS 620.

Using the PTWS 620 within an automated system offers the operator full access to the vessels before and at the end of a run as the complete drive head is lifted electronically.

Sampling sequence timing is programmed using the menu system of the PTWS 620 instrument, while sampling volume and the optional media refilling process is programmed at either the PTFC-2/8 or DSR-M.


  • Automated temperature check and log at all sampling times
  • Fully USP <711/724> and EP <2.9.3/4> compliant
  • 8 stirred positions in a 6 + 2 arrangement
  • Rigid motorized lift drive to raise and lower the head
  • Individually coded Borosilicate vessels
  • File up a nearly unlimited number of different test descriptions (methods)
  • Instrument suitability check prior to start of a test run
  • Staggered start capability
  • Vessel low evaporation sealing covers
  • Drainage tap to empty the bath
  • CFR compliant method management and user administration with access control
  • Built-in thermo printer to print a test-log at the end of a run
  • Optical and acoustic signals to inform about sampling intervals, timer count down function
  • Status bar with traffic light information on display shows the instrument status by different colors (green = ready to use, yellow = preparing to use, red = error encountered)
  • OQ, PQ interval warning with programmable interval
  • Interfaces: USB port for remote control of the PTWS 620, RS-232 port to connect serial devices, I/O port for remote control of external instruments in automated applications, like DSR-M, pumps and PTFC-2/8
  • Calibration menu for stirrer speed, bath temperature


  • 6 front line vessels for easy access in manual operation and optimal visibility
  • Rigid aluminum water bath cover
  • Individual 3-point vessel centering
  • Excellent access to all vessels
  • Staggered start feature for convenient manual sampling
  • Screen saver functionality offers most important information at a glance (stirrer speed, bath temperature, time to next sampling interval, elapsed time, media temperature etc.)
  • Wake up functionality to start heating at a pre-programmed time
  • Programmable infinity test
  • MonoShaft™ system to avoid re-adjustment of immersion depth
  • Ultra-fast heating system with excellent temperature stability due to newly designed heat exchanger
  • Water diffuser for even temperature distribution
  • Vibration absorber to avoid vibration transfer into the USP/EP vessels
  • Spring loaded pump assembly to eliminate vibration transfer to the frame work
  • Extraordinary safety features for pump and heating system, flow control, digital temperature control, water level sensor, thermo switch, thermo fuse
  • DQ/QC, IQ and OQ documents included free of charge

Technical Specifications

Parameter Specification
Display 6″- 320*240 pixel color LCD, illuminated
Data Entry Resistive touch screen, alpha-numerical and functional keys
Acoustic Signal Acoustic signal for operator information at programmable intervals
Timer Programmable sampling times, wake-up and sleeping mode, operation time information and timer count-down mode
Stirrer Position 8 freely programmable stirrer immersion positions (paddle over disk, transdermal cylinder etc.)
Testing Method Descriptions Unlimited number of test descriptions can be stored on SD card
User Access Control Multiple level access control
OQ, PQ control Programmable time periods to remind about QO or PQ testing
Printer Built-in thermo printer
Number of Stirred Vessels 8 (6 + 2 arrangement)
Standard Vessels 1 liter USP/EP Borosilicate glass vessel, each individually coded
Speed Control 25 – 250 RPM
Speed Accuracy ±2% of set speed, typically < 1%
Stirrer Shaft Wobble Better than 0.2 mm total run out
System Tools MonoShaft™ stirrer design, USP/EP apparatus 1, 2, 5, 6 tool adapter, cream cell, transdermal patch tools, tools & vessels individually coded
Heating System Pump for water circulation and 1400W heater for fast heating up
Heater Range 25 – 45°C
Heater Accuracy ± 0.2°C inside the water bath
Heat Up Process Energy saving, programmable “wake up” function and “sleep mode”
Water Circulation Water circulated from external heating system through special diffuser inside the water bath
Vibration Elimination Water bath rests on vibration absorbers, spring loaded pump assembly
Calibration Built-in calibration procedures for speed, temperature control, OQ/PQ interval programmable including alarm indicator
Bench Space Requirements Approx. 112 x 58 cm
Packaging Approx. 137 x 78 x 87 cm (W x D x H)
Weight 75 kg net weight, 100 kg gross weight
Certification All components certified to USP / EP requirements

We reserve the right to make technical changes without any prior notice.

Included in the Standard Scope of Supply

  • One set of stainless steel paddles
  • One set of batch coded 1000ml Borosilicate glass vessels
  • One set of depth adjustment balls
  • One bottle of ALGEX water preservative
  • Comprehensive documentation folder including:
    • User manual
    • DQ/QC instrument compliance test certificate
    • IQ documentation
    • OQ documentation
    • Instrument logbook
    • Compliance certificates for vessels and stirring tools


  • Direct control of peripheral instruments via I/O port such as PTFC-2/8 fraction collector or DSR-M Sampling Robot
  • Eco saving double walled vacuum molded water bath
  • 2 liter vessel version (can also be used with 1 liter vessels)
  • 250 ml Mini Vessel set incl. mini paddle stirrers
  • Amber colored vessels for UV sensitive test materials
  • Full range of MonoShaft™ stirring tools available
  • Full range of certified validation tools available
  • PT-RP80 serial report printer

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