Synthesis, recognition properties and drug release behavior of diltiazem-imprinted chitosan-based biomaterials

In this study, we prepared diltiazem (DTZ)-imprinted biomaterials for TDDS using chitosan, PVA, plasticizers, and sulfosuccinic acid. DTZ and the prepared biomaterials were characterized using field emission scanning electron microscopy, Fourier transform infrared, and ¹H nuclear magnetic resonance. DTZ recognition properties were confirmed by the binding isotherm, Scatchard plot analysis, the adsorption of materials with structures similar to DTZ, selectivity factor (α), and the imprinting-induced promotion of binding (IPB). Results revealed that adsorbed amount (Q) of DTZ-imprinted biomaterials was 1.63–2.53 times higher than that of non-imprinted biomaterials. In addition, it could be verified that DTZ-imprinted biomaterials have a binding site for DTZ according to Scatchard plot analysis. Furthermore, the results of α and IPB indicated that the recognition capacity of the prepared DTZ-imprinted biomaterials is superior to that non-imprinted biomaterials. DTZ release properties were evaluated under various pH buffers and artificial skin. Results indicated that the DTZ release in buffers at low pH was faster than that in buffers at high pH. The DTZ release using artificial skin was continuous over 20 days. Furthermore, the DTZ release profile in the buffer followed the pseudo-Fickian diffusion mechanism, whereas the profile in the artificial skin test followed a non-Fickian diffusion mechanism.