Vesicles prepared by β-cyclodextrins Inclusion complexes based on switching supramolecular interaction models induced by mixed solvents

Spectral and molecular modeling investigations of supramolecular complexes of mefenamic acid and aceclofenac with α- and β-cyclodextrin

Inclusion complexes of mefenamic acid (MFA) and aceclofenac (ALF) with α- and β-cyclodextrins (CDs) in aqueous medium were investigated by absorption, fluorescence, time-resolved fluorescence methods. The solid inclusion complexes between drugs and CDs were characterized by SEM, TEM, FT-IR, ¹H NMR, DSC and powder XRD techniques. Spectral studies indicated that both CDs form 1:1 inclusion complex with MFA and ALF. The experimental results revealed that the inclusion process is a spontaneous process. Time-resolved fluorescence studies suggested that ALF exhibited biexponential decay in aqueous and triexponential decay in CD whereas significant enhancement of lifetime of decay components of MFA was observed. Morphologies of drug-CD complexes observed by TEM demonstrate that self-aggregates of MFA/α-CD, ALF/α-CD and ALF/β-CD were nano-sized particles while vesicles were observed for MFA/β-CD. A spatial arrangement of inclusion complex is proposed based on ¹H NMR and PM3 results. Investigations of thermodynamic and electronic properties confirmed the stability of the inclusion complex.

Inclusion complexation of isoprenaline and methyl dopa with α- and β-cyclodextrin nanocavities: spectral and theoretical study

Inclusion complex formation of isoprenaline (ISOP) and methyldopa (MDOP) with α-CD and β-CD were investigated. Solid inclusion complex nanomaterials were characterized by SEM, TEM, FTIR, DSC, (1)H NMR and XRD methods. Spectral results showed that single emission (monomer) noticed in aqueous solution where as dual emission (excimer) in CD. Both drugs formed 1:2 (CD-drug2) inclusion complexes with CDs. Time-resolved fluorescence studies show that single exponential decay observed in water whereas biexponential decay observed in CD. Nano-sized particles were found in ISOP/CD while vesicles were obtained in MDOP/CD complexes. DSC results revealed that the thermal stability of drugs was improved when it was included in the CD nanocavity. Based on PM3 calculations, the inclusion structure of ISOP/CD and MDOP/CD complexes were proposed. Thermodynamic parameters and binding affinity of complexation of CD were determined by PM3 method.