Analysis of the dissolution behavior and solubility of Rotigotine form II in different mono-solvents

The form II of Rotigotine (RTG), a dopamine agonist used to treat Parkinson's disease and Wills-Ekbom disease, is a stable crystal that is suitable for industrial production. In our study, we measured the solu-bility of RTG in ten solvents, including alcohols and esters, using UV spectrophotometry at temperatures ranging from 278.15 to 313.15 K and atmospheric pressure. Our results showed an increasing trend in solubility with temperature and an increase in carbon chain length of the solvents, except for 2-propanol and isopropyl acetate. By fitting six thermodynamic models to the solubility data, we found strong correlation. Simulation calculations indicated that H-H and C-H bonds are dominant among RTG molecules, and the solubility of RTG has a positive trend with the increase in viscosity and carbon chain length of the solvents.(c) 2023 Elsevier B.V. All rights reserved.

Automated summary

In this study, the solubility of RTG in ten solvents was measured using UV spectrophotometry. The results showed that the solubility increased with temperature and carbon chain length of the solvents, except for 2-propanol and isopropyl acetate. Six thermodynamic models were fitted to the solubility data, showing a strong correlation. Simulation calculations indicated that H-H and C-H bonds are dominant among RTG molecules, and the solubility of RTG has a positive trend with the increase in viscosity and carbon chain length of the solvents.