Preparation of metal ion-mediated Furosemide molecularly imprinted polymer: synthesis, characterization, and drug release studies

In the present study, a molecularly imprinted polymer (MIP) was prepared for Furosemide drug as template molecule in H₂O/THF (1:1 v/v) medium using Fe³⁺ as metal ion mediator. Acrylic acid, acrylamide, and N,N′-methylenebis(acrylamide) were used as functional monomer, comonomer, and cross-linking agent, respectively. Different binding and selectivity parameters of the prepared system were studied and compared with the corresponding metal ion-free MIP and non-imprinted polymer (NIP). The presence of the metal ion during pre-assembly step showed a significant influence on the imprinting ability of the resulting polymeric network due to its strong interactions with the template molecule and the functional monomer. Besides, structural, thermal, and morphological characterizations of the prepared system were investigated. In the final step, the in vitro release study of Furosemide from the synthesized polymers was carried out in pH = 7.41 phosphate-buffered saline solution at 37 °C. Results indicated that the Fe³⁺-mediated MIP (Fe-MIP) has larger drug loading capacity and higher amount of drug release at its equilibrium state. Moreover, according to the drug release profiles, the drug release rate of the Fe-MIP is more controlled than that of the MIP and the NIP, especially at the early stages of release.