ERWEKA Offline Dissolution Testers Overview

ERWEKA offline dissolution testers are automated sampling systems controlled by a DT 820 series dissolution tester with fraction collector. The ERWEKA DT 820 series offers advanced intelligence and features for stand-alone operation or for control of the dissolution offline sampling system. It allows storage of up to 60 product test-run parameters. Fully CFR Part II software is also available for this bath upon request (click here for more).

DT 820 dissolution testers come with integrated intelligence for controlling the offline sampling system, which consists of a auto-sampling station connected to the DT, an  8-channel peristaltic pump IPC 8 and the sample collector FRL 824 for storing the samples into glass tubes or sealed HPLC vials.

This configuration does not require an additional PC or any software and therefore saves space, money and last but not least software validation work.

Download the Offline System Spec Sheet here.


Automated Sampling Station

The ERWEKA automated sampling station ASS-8 with automatic height adjustment takes into account the applied method and the used media volume. Similar to manual sampling the tubes are inserted into the media only for sampling time needed and withdrawn after sampling is finished. Since this system adheres to USP requirements and cross validation is not required.

Dissolution Testers


Sample collection

Peristaltic Pump IPC-8

With the standard ERWEKA 8-channel peristaltic pump IPC 8 the sample is withdrawn from the dissolution tester vessel and transferred to the sample collector FRL x24. The pump tubings are made of Verderprene (similar to Fluoropolymer) to prevent the absorption of active ingredients. Alternatively a high pressure piston pump PVP 620 or 820 (6 or 8 channels only) allows filtration from 0.22 μm. With a high precision syringe pump type SP automated dilution of the sample in ratio up to 1:10 is possible.

Sample collection with the FRL

Dosing is performed by overfilling and levelling or 3-way solenoid valves incorporated into the sample collector FRL 624 / 724 or 824 with 6, 7 or 8 channels. There are several sampling possibilities of max. 26 sampling intervals into glass tubes or glass tubes and sealed/unsealed HPLC vials as well as media replacement.

  • Easy access to sample tubes
  • Easy to clean
  • Up to 26 rows for extended release formulation testing
  • Integrated cleaning procedure
  • Needles available in stainless steel or titanium for sensitive APIs, HPLC vials and glass tubes
  • Special procedure for foaming medias handling
  • Automated flush routine between sampling intervals
  • Gentle and precise spindle drive of the sample collector FRL
  • Movable trays provide easy exchange of different racks
  • Different racks available for glass tubes or HPLC vials

Racks available

  • 26 x 8 glass tubes 12 ml
  • 18 x 8 glass tubes 25 ml
  • 26 x 8 HPLC vials 1.5 ml
  • 26 x 8 HPLC vials 4.0 ml

Dissolution Testers

14 Vessel Offline Systems with DT 1610

In combination with the 14 vessel DT 1610 range of dissolution testers, the automated sampling and media replacement can be performed in 14 vessels simultaneously. In this case a peristaltic pump IPC-16 is included in the system.

Ultra Filtration (below 1.0 μm) – AFC 825

For HPLC analysis (but also to fulfil the regulations of the Japanese and Russian Pharmacopeia) filtration below 1.0 μm has to be performed. Since filters below 1.0 μm porosity usually are blocked after use they have to be exchanged after each sampling interval.

ERWEKA has developed the AFC 825 filter changer, which automatically replaces used membrane with new ones. The AFC 825 can be used in Offline Systems ( controlled via DT 820 Dissolution Testers ) as well as in UV-VIS On- and UV-VIS Off-/Online Systems (controlled via the ERWEKA Dissolution Software).

Filtration down to 0.22 μm is possible in combination with the high-pressure PVP 820 Piston Pump (1.0 μm in combination with Syringe- and Peristaltic Pumps). Filters can be exchanged either after each test run or after each sample withdrawal interval.

Technical Details

Dissolution Tester/s ERWEKA DT 820
Pumps IPC 8 peristaltic pump 8-channel peristaltic pump, RS 232 serial interface for external control, touch sensitive keys and LC display, Verderprene tubing for elimination of absorption of active ingredients
Fraction Collector FRL 824 Sample collector FRL for sampling up to 24 sampling intervals; movable tray for easy exchange of racks; 1 driven dosing arm with 8 stainless steel dosing tubes, RS 232 interface for external control by the dissolution tester DT 82x series.
Sampling Containers 26x 8 glass tubes of 12 ml capacity;16x 8 glass tubes of 25 ml capacity;26x 8 HPLC vials of 1.2 ml or 4.0 ml capacity
Membrane Piercing The FRL 824 offers HPLC vial membrane piercing to fill into sealed HPLC vials
Media Replenishment The FRL 824 offers to replenish the withdrawn (stored) media volume by fresh media from a integrated container.
Dilution As option the FRL 824 automates dilution of the stored sample up to 1:10 with an accuracy of ± 0.1 ml (10 ml syringes), only in combination wiht syringe pump SP 640 or 840 (6 or 8 channels)
Tubing fluoropolymer tubing
Cleaning The FRL 824 offers an automated cleaning routine between each sampling interval
System Control DT 820 Series with i-Version upgrade for control of a complete offline system including sample transfer pump and sample collector FRL. Fully CFR Part II software is also available for this bath upon request (click here for more).


  • Rack (24x 8) with glass tubes of 10 ml volume
  • Rack (16x 8) with glass tubes of 25 ml volume
  • Rack (24x 8) for HPLC vials, 1.2 ml volume
  • Rack (24x 8) for HPLC vials, 4.0 ml volume
  • IQ/OQ/PV documents with all dissolution testers
  • Q/OQ/PV service
  • Maintenance contracts