Abstract
A combination of Fourier transform infrared spectroscopy in attenuated total reflectance geometry (FTIR-ATR) and 2D correlation analysis (2D-COS) was applied here for the first time in order to investigate the temperature-dependent dynamical evolution occurring in a particular type of inclusion complex, based on sulfobutylether-β-cyclodextrin (SBE-β-CD) as hosting agent and Coumestrol (7,12-dihydorxcoumestane, Coum), a poorly-soluble active compound known for its anti-viral and anti-oxidant activity. For this purpose, synchronous and asynchronous 2D spectra were calculated in three different wavenumber regions (960–1320 cm−1, 1580–1760 cm−1 and 2780–3750 cm−1) and over a temperature range between 250 K and 340 K. The resolution enhancement provided by the 2D-COS offers the possibility to extract the sequential order of events tracked by specific functional groups of the system, and allows, at the same time, the overcoming of some of the limits associated with conventional 1D FTIR-ATR analysis. Acquired information could be used, in principle, for the definition of an optimized procedure capable to provide high-performance T-sensitive drug carrier systems for different applications.
Highlights
Over the last years, many efforts have been devoted to the design of high-performance drug delivery systems capable to transport suitable dosage of the drug with high spatial and temporal accuracy
As already reported [42], the complexation process occurring between Coum and SBE-β-CD was testified by dissimilarities in the experimental 1D FTIR-ATR spectra of the
We focused on the dynamical behavior exhibited by the Coum/SBE-β-CD material upon thermal stimuli, resulting from the application of an upward temperature trajectory, that follows a well-defined “time” sequence that cannot be highlighted by conventional 1D FTIR-ATR analyses
Summary
Many efforts have been devoted to the design of high-performance drug delivery systems capable to transport suitable dosage of the drug with high spatial and temporal accuracy. As is well-known, drugs administered through conventional routes may lead to a series of unwanted effects mainly induced by their poor water solubility in lipophilic solvents and insufficient bioavailability [1,2,3,4,5,6,7], strongly limiting their pharmacological efficacy In this context, supramolecular compounds based on natural and modified cyclodextrins (CDs and MCDs, respectively) represent an attractive strategy for the engineering of bio-friendly host-guest inclusion complexes capable to improve the chemical/physical properties of pharmaceutical agents both in solution or in solid state [8,9,10,11,12]. It is worth noting that the partial overlap of several vibrational bands ascribed to both Coum and SBE-β-CD molecules makes the definition of an unambiguous assignment of each spectral feature and its evolution vs T difficult to accomplish by 1D FTIR-ATR spectroscopy In this context, 2D-COS analysis overcomes this limitation, furnishing information on the time-step sequence of events affecting the molecular dynamics of SBEβ-CD-based inclusion complexes, not accessible through conventional analysis. Knowledge of the aforementioned additional aspects could furnish useful insights for the development of next-generation CD-based drug carriers providing, at the same time, a detailed scenario of the Coum/SBE-β-CD complex behavior when exposed to temperature perturbations
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
