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AAPS PharmSciTech

, Volume 14, Issue 2, pp 517–522 | Cite as

An Automated System for Monitoring and Regulating the pH of Bicarbonate Buffers

  • Grzegorz Garbacz
  • Bartosz Kołodziej
  • Mirko Koziolek
  • Werner Weitschies
  • Sandra Klein
Brief/Technical Note

Abstract

The bicarbonate buffer is considered as the most biorelevant buffer system for the simulation of intestinal conditions. However, its use in dissolution testing of solid oral dosage forms is very limited. The reason for this is the thermodynamic instability of the solution containing hydrogen carbonate ions and carbonic acid. The spontaneous loss of carbon dioxide (CO2) from the solution results in an uncontrolled increase of the pH. In order to maintain the pH on the desired level, either a CO2 loss must be completely avoided or the escaped CO2 has to be replaced by quantitative substitution, i.e. feeding the solution with the respective amount of gas, which re-acidifies the buffer after dissociation. The present work aimed at the development of a device enabling an automatic pH monitoring and regulation of hydrogen carbonate buffers during dissolution tests.

Key words

bicarbonate media hydrogen carbonate buffer modified release physiological buffers biorelevant dissolution 

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Copyright information

© American Association of Pharmaceutical Scientists 2013

Authors and Affiliations

  • Grzegorz Garbacz
    • 1
    • 2
  • Bartosz Kołodziej
    • 3
  • Mirko Koziolek
    • 2
  • Werner Weitschies
    • 2
  • Sandra Klein
    • 2
  1. 1.Physiolution GmbHGreifswaldGermany
  2. 2.Institute of Biopharmaceutics and Pharmaceutical Technology, Department of PharmacyUniversity of GreifswaldGreifswaldGermany
  3. 3.Institute of Low Temperature and Structure ResearchPolish Academy of Sciences in WrocławWrocławPoland

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