pH adjustment and monitoring
of hydrogen carbonate buffers
Physiolution GmbH
Walther-Rathenau-Strasse 49a
17489 Greifswald, Germany
www.physio-stat.com
electrode potential
CO2
electrode
CO2
CO2 diffusor
The pHysio-stat® enables pH adjustment and monitoring of hydrogen carbonate buffers during dissolution testing.
The pHysio-stat® is an automated microprocessor-driven system which enables the adjustment of the media pH
in a dissolution vessel.
The pHysio-stat® is composed of a pH electrode, a gas diffusor, a digital microcontroller and a proportional valve.
The device is driven by custom-made software which controls the pH adjustment in the range of pH 5.5 to 9.0 and
enables the setting of trigger values as well as a regulation hysteresis within the pharmacopoeial tolerance range
of ± 0.05 pH. The pH electrode and the gas diffusor remain immersed in the dissolution medium. This allows that
the pH is measured over the entire dissolution experiment and is instantly applicable for the regulation of the proportional valve that adjusts the amount of CO2 introduced into the dissolution medium via the diffusor.
The pHysio-stat® device:
• can precisely monitor and adjust the pH value
of commonly used hydrogen carbonate buffers such as Hanks and Krebs buffer solutions
and modifications of biorelevant media
• enables a precise pH adjustment in the range
of pH 5.5 to 9.0 with a maximum deviation
of ± 0.05 pH units
• utilizes pure CO2 as well as mixtures of CO2
with other gases as a titer
• is characterized by high robustness, excellent performance stability as well as extre­
mely high dynamics of the pH adjustment
processes
• can be used in various pharmacopoeial and
non-compendial dissolution test devices.
These unique features make the pHysio-stat®
not only very useful for applications in research
and development but also very efficient for routine applications in dissolution tests in which
hydrogen carbonate based buffers are utilized.
Physiolution GmbH
Walther-Rathenau-Strasse 49a
17489 Greifswald, Germany
www.physio-stat.com
Grzegorz Garbacz, Ph.D.
[email protected]