How the System Works

1.

2.

3.

4.

5.

The diagram illustrates sampling from one diffusion cell. The MicroettePlus system simultaneously samples and collects from groups of six cells.

The system is set up by filling each diffusion cell with heated deaerated receptor solution from the media beaker. A measured volume and thickness of drug formulation is then placed on the membrane in the cell donor chamber to start the test.

The MicroettePlus saves up to 25 protocols for sampling volumes and time points, including advanced routines for cell dilution and other requirements. A given protocol is activated to initiate the start.

Sample aliquots are collected and archived in sealed-septum HPLC vials in the MultiFill collector. When each sampling point is complete, the Helix stirrer starts again to restore homogeneity.

Sample aliquots are collected and archived in sealed-septum HPLC vials in the MultiFill collector. When each sampling point is complete, the Helix stirrer starts again to restore homogeneity.

6.

7.

8.

9.

10.

A rinse cycle just before each sampling cycle ejects contents of the sample tube to waste. This cleans the sample lines prior to sampling and collection.

This sampling and collection sequence continues for each programmed time point until the end of the test. The validation printer provides an on-going status report of all test operating conditions.

The use of advanced "scripting" allows for special protocol routines, including cell dilution at selected time points.

Throughout the test, the heater circulating bath maintains controlled temperature in the media replacement beaker and each diffusion cell (typically 32°C for skin permeation studies).

Collected samples archived in interchangeable racks may be removed at the convenience of the scientist for HPLC and other method analysis.