Host-guest interaction of anti-carcinogenic drug zoledronic acid with β-cyclodextrin in solid and solution forms

Abstract

Zoledronic acid (ZA) molecule is very important drug used in the treatment of cancer such as prostate, renal and lung cancers. However, it has some disadvantages such as stability and solubility, as well as the disadvantages of many other cancer drugs such as release and undesirable side effects. Therefore, a complex was formed between ZA molecule and beta cyclodextrin (β-CD) which is a good drug carrier system to eliminate the disadvantages of ZA molecule. In this study, complex formed by host (β-CD) and guest (ZA) molecules was obtained and the binding of ZA with β-CD was examined using UV-Vis, FT-IR, NMR spectroscopic methods, powder XRD and thermal analysis methods. Absorption measurements indicated that any chemical shift in UV-Vis spectrum of ZA molecule was not observed after interacting with β-CD molecule. Moreover, as the concentration of β-CD molecule increased, absorbance value of ZA molecule decreased in the solution form. NMR and FT-IR spectra showed that chemical interactions between ZA and β-CD molecules were observed. These interactions were observed especially between the P-OH, C-OH and CN groups of the ZA molecule and the groups in the inner cavity of β-CD. On the other hand, according to thermal analysis results, thermal stability of complex molecule (ZA/ β-CD) was increased when it was compared with ZA and β-CD molecules.