<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Substances in the form of weak acid salts have been found to be problematic for dissolution testing. Their absorption can start only after they are turned into the form of an acid following the gastric passage although they were administered in the form of a salt. Due to poor solubility, they cannot be tested in acidic gastric environment for a biased dissolution profile. The biphasic dissolution method is promising for overcoming this obstacle. Tablets with warfarin clathrate sodium salt in two concentrations and two different particle size distributions were tested as a suitable model for finding the medium and process conditions of dissolution. The dissolution method based on the use of the upper organic layer (1-octanol) and the lower aqueous layer 0.1 mol L<sup>−1</sup> HCl) was found suitable and discriminatory for tablets containing active substances in the form of salts of weak acids. The method also reflects physical differences in the quality of used substances.</p></abstract>

Substances in the form of weak acid salts have been found to be problematic for dissolution testing. Their absorption can start only after they are turned into the form of an acid following the gastric passage although they were administered in the form of a salt. Due to poor solubility, they cannot be tested in acidic gastric environment for a biased dissolution profile. The biphasic dissolution method is promising for overcoming this obstacle. Tablets with warfarin clathrate sodium salt in two concentrations and two different particle size distributions were tested as a suitable model for finding the medium and process conditions of dissolution. The dissolution method based on the use of the upper organic layer (1-octanol) and the lower aqueous layer 0.1 mol L−1 HCl) was found suitable and discriminatory for tablets containing active substances in the form of salts of weak acids. The method also reflects physical differences in the quality of used substances.

Biphasic dissolution method for quality control and assurance of drugs containing active substances in the form of weak acid salts

Department of Pharmaceutics, Faculty of Pharmacy, University of Veterinary and Pharmaceutical Sciences, Brno, Czech Republic

Masaryk Memorial Cancer Institute, Brno, Czech Republic

Acta Pharmaceutica

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Substances in the form of weak acid salts have been found to be problematic for dissolution testing. Their absorption can start only after they are turned into...

Biphasic dissolution method for quality control and assurance of drugs containing active substances in the form of weak acid salts

Published Online: Mar 07, 2016

Page range: 139 - 145

Accepted: Sep 29, 2015

DOI: https://doi.org/10.1515/acph-2016-0010

Keywords
weak acid salts, warfarin sodium, dissolution method

© 2016 Aleš Franc et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Biphasic dissolution method for quality control and assurance of drugs containing active substances in the form of weak acid salts

Published Online: Mar 07, 2016

Page range: 139 - 145

Accepted: Sep 29, 2015

DOI: https://doi.org/10.1515/acph-2016-0010

Keywordsweak acid salts, warfarin sodium, dissolution method

© 2016 Aleš Franc et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
weak acid salts, warfarin sodium, dissolution method