Media Preparation System

The PT-DDS4 media preparation and degassing instrument is a vital part of a dissolution testing system. Deaerated media are critical to the reproducibility of dissolution results. The PT-DDS4 can prepare up to 25 litres of pre-heated media, which is degassed by a combination of heating, vacuum and circulation.

The USP reference standard tablets, are used to perform a dissolution instrument suitability test after a successful physical parameter qualification (OQ). During this suitability test, the quality of degassing has a significant effect upon the test results obtained; as does vibration. Naturally, the mechanical “fitness” of the instrument has to be established and is usually achieved by performing the OQ prior to the USP suitability test. Low vibration levels, low wobble, correct tool centering and precise tool depth settings are just some of the factors which may affect a successful qualification – but media degassing is one of the most influential factors.

The PT-DDS4 media preparation system has proven in many tests and in general operation, that its automated degassing and dosing procedure fulfills the requirements of both the FDA and USP and that the USP Prednisone qualification test (PVT) will successfully be achieved. The prepared media (water or buffer) can either be filled directly into the media tank or it can be automatically primed using the on-board vacuum pump and the internal liquid level sensor which controls the pre-filling volume. Select your method of choice and enter the maximum volume. It is also possible to mix a buffer using de-mineralised water and a buffer concentrate, if the on-line buffer mix option is installed.

The instrument’s keyboard and LC-Display are used to file product and de-aeration information. Enter and file descriptive data for the number of media doses required, user data, media information and so on. All method related data as well as the dosage reports can be saved to hard copy using the built-in printer. A maximum of 16 product and de-aeration method files can be saved. As soon as all data is entered, the de-aeration process can start. While the media is heated, it is constantly circulated under vacuum within the tank. The de-aeration process needs about 30 to 45 minutes for approx. 25 litres of media. Thereafter, 25 litres of deaerated and pre-heated media are available for either gravimetric or volumetric dosing.

Volumetric dosing will allow on-line dispensing directly into the dissolution vessels. The PT-DDS4 is equipped, as standard, with a built-in load cell which is used to precisely measure the dosing volume. It is also used to qualify and adjust the dosing accuracy. A dissolution vessel holder supports the empty vessel beneath the dosing tube. The number of medium dosages as well as the actual dosed volume and any deviation from target volume is reported via the built-in printer.


  • Complies to USP, EP and FDA requirements
  • Prepares up to 25 litres of pre-heated and degassed medium
  • Medium is heated and constantly circulated while being degassed by vacuum
  • Media degassing is one of the most influential factors on USP suitability tests
  • Gravimetric dosing included as standard by means of an integrated load cell
  • Volumetric dosing directly into dissolution vessels available as option
  • Integrated cleaning program
  • Integrated qualification and calibration procedure
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