Autor: M. D. Likar, Russell H. Robins, Paul E. Fagerness, Richard J. Taylor, Yukio Hiyama
Rok vydání: 1993
Předmět:
Zdroj: Pharmaceutical Research. 10:75-79
ISSN: 0724-8741
DOI: 10.1023/a:1018925113721
Popis: Understanding how moisture interacts with a drug or formulation is a critical component of product development. This study demonstrates how water affects the 3′-gem-diol ↔ 3′-keto equilibrium in trospectomycin sulfate bulk drug and freeze-dried formulation, as probed by solid-state carbon-13 cross-polarization magic angle spinning (CP/MAS) and high-resolution nuclear magnetic resonance (NMR) spectroscopy. Drying the bulk drug or formulation to low water levels dehydrates trospectomycin sulfate from the diol to the keto form. Carbon-13 CP/MAS NMR spectroscopy measures the keto drug concentration in solid samples directly. The bulk drug, which contains approximately 16% water, is more than 90% in the 3′-diol form. Oven drying to 95%) of the drug is in the 3′-diol form. After equilibration at 60°C, however, the 3′-keto content increases to 7%, and in d 6-DMSO solvent at 25°C the drug is mostly (60%) in the 3′-keto form.
Databáze: OpenAIRE