Publication Date:
2014-07-26
Description:
The pH-solubility profiles of a model drug in salt form were established and the mechanism of salt-to-free base form transformation was investigated by increasing pH of the system. Wet massing experiments together with suspension experiments were performed to investigate the effects of excipients on the stability of the salt form. It was found that nucleation of the free base did not happen at pH max but that instead a new boundary, the pH metastable , had to be reached before transformation occurred. It was also demonstrated that some excipients influence the stability of the drug, which can help find excipients that previously would have been excluded on basis of a pH higher than pH max but still lower than pH metastable . The application of Raman spectroscopy to monitor procaine concentration with a very large concentration span was proven to be possible. In experiments with additives in wet massing, only MgO influenced the drug stability. Simply determining pH max is not sufficient in order to determine the excipients that may be used without adverse effects in drug manufacturing.
Print ISSN:
0930-7516
Electronic ISSN:
1521-4125
Topics:
Chemistry and Pharmacology
,
Process Engineering, Biotechnology, Nutrition Technology
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