Infrared spectroscopic study of triacetyl‒β‒cyclodextrin and its inclusion complex with nicardipine

Abstract

Infrared spectra of inclusion compounds of triacetyl‒β‒cyclodextrin with nicardipine hydrochloride were compared and analysed with those corresponding to their physical mixture and the pure compounds, respectively. Different O–H stretching vibrations, assigned to water molecules, were located in the Fourier Transform Infrared (FT IR) spectra of triacetyl‒β‒cyclodextrin, and its inclusion complex with nicardipine obtained by spray‒drying (SD) method. Water molecules involved in various hydrogen bonds environments change their status during complexation process. Evidences are observed of the formation of the complex especially in the spectral regions of the amino and carbonyl stretching vibrations.

Effect of Cross-Linking Properties on the Vibrational Dynamics of Cyclodextrins-Based Polymers: An Experimental–Numerical Study

“…According to this model, the O−H stretching profile can be well reproduced by using five spectral contributions assigned to vibrations involving the OH groups of interstitial and intracavity water molecules and the primary and secondary OH groups of cyclodextrin. 29,30 We remark that, in the case of PMA−nanosponges, the OH groups present in the PMA molecule give additional contributions overlapped with those arising from the CD units and that the separation of these spectral components can become not meaningful. For this reason, we decided to apply the approach described above only to β-CDPMA nanosponges obtained by using the lowest β-CD/PMA molar ratio, i.e., 1:2 and 1:2.5.…”

“…29,30 In the case of β-CDPMA nanosponges, by increasing the amount of the crosslinking agent, water molecules are forced to change their environment and rearrange in a new hydrogen bonds scheme, that will be characterized by a major number of interstitial hydrogen-bonded clusters of water molecules (I 1 + I 3 increases of ∼8.5%, while I 5 remains essentially unchanged within the experimental error).…”

Isoflavone aglycons-sulfobutyl ether-β-cyclodextrin inclusion complexes: in solution and solid state studies

“…The main results, i.e. centre-frequency and percentage intensity of each subband, are reported in Table 1, together with an assignment of each contribution, based on previous works on similar systems [32,[49][50][51].…”

UV–vis and FTIR–ATR spectroscopic techniques to study the inclusion complexes of genistein with β-cyclodextrins

“…In the case of Gen/␤-CyDs physical mixtures and complexes, the O-H stretching vibrational modes coming from primary and secondary O H groups of ␤-CyDs, from crystallization water molecules (interstitial and intracavity), and from the hydroxyl groups of the guest molecules are revealed in the ∼3700 to ∼3100 cm −1 range [36,37]. In principle, these contributions, that usually appear overlapped, give rise to very broad bands, and this makes the analysis of this spectral profile not easy.…”