Wang Xiaofeng, Huang Jiaqi, Yang Dengchen, Huang Ting, Yang Yang, Tu Jiasheng, Zou Jian, Sun Huimin, Zhao Xia, Yang Rui
NMPA Key Laboratory for Quality Research and Evaluation of Pharmaceutical Excipients, National Institutes for Food and Drug Control, Beijing 100050, China.
Center for Research Development and Evaluation of Pharmaceutical Excipients and Generic Drugs, Department of Pharmaceutics, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China.
Pharmaceutics. 2024 Jul 10;16(7):919. doi: 10.3390/pharmaceutics16070919.
The encapsulation of sodium sulfobutylether-β-cyclodextrin (SBE-β-CD) is influenced not only by the degree of substitution (DS) but also by the presence of strong-bonded water (SBW). Guests compete with SBW for positions within the cavity of SBE-β-CD. However, the correlation between DS and SBW was not clear. This study revealed a positive correlation between DS and SBW utilizing Karl Fischer titration. The mechanism may be attributed to molecular polarizability. To explore the impact of SBW inside SBE-β-CD with different DS on encapsulation, density functional theory was employed. Throughout the release process, an increase in enthalpy is unfavorable, while an increase in entropy favors spontaneous reaction occurrence. For SBE-β-CD (DS = 2, 3), enthalpy increase is the primary factor, leading to the retention of SBW within the cavities and consequently hindering guest entry. In contrast, for SBE-β-CD (DS = 4, 7), the situation differs. For SBE-β-CD, the influence of SBW is minimal. This study aims to elucidate the relationship between DS and SBW, as well as the effect of SBW inside SBE-β-CD with different DS on encapsulation. It is crucial for a comprehensive understanding of the factors affecting the encapsulation of SBE-β-CD, thereby promoting quality control and functional development of SBE-β-CD.
磺丁基醚-β-环糊精（SBE-β-CD）的包封不仅受取代度（DS）的影响，还受强结合水（SBW）的存在影响。客体与SBW竞争SBE-β-CD腔内的位置。然而，DS与SBW之间的相关性并不明确。本研究利用卡尔费休滴定法揭示了DS与SBW之间的正相关关系。其机制可能归因于分子极化率。为了探究不同DS的SBE-β-CD内部SBW对包封的影响，采用了密度泛函理论。在整个释放过程中，焓增加不利于反应，而熵增加有利于自发反应的发生。对于SBE-β-CD（DS = 2, 3），焓增加是主要因素，导致SBW保留在腔内，从而阻碍客体进入。相比之下，对于SBE-β-CD（DS = 4, 7），情况有所不同。对于SBE-β-CD，SBW的影响最小。本研究旨在阐明DS与SBW之间的关系，以及不同DS的SBE-β-CD内部SBW对包封的影响。这对于全面理解影响SBE-β-CD包封的因素至关重要，从而促进SBE-β-CD的质量控制和功能开发。
