Inhibitive effect of super paramagnetic iron oxide nanoparticles on the alkaline hydrolysis of procaine

The Super Paramagnetic Iron Oxide Nanoparticles (SPIONs) can bind drugs and act as drug-carriers. The magnetically active SPIONs can be used to deliver the drugs to the target through magnetic fields. The objective of the present work has been undertaken to study the stability, and binding behaviour of procaine with SPIONs and surfactant-coated SPIONs. Procaine is among the ester drugs and hydrolyses in the alkaline medium. The influence of SPIONs and surfactant-coated SPIONs on the rate of hydrolysis of procaine in alkaline medium may help to define the behaviour of the drug in the presence of these nanoparticles. The kinetic studies of procaine hydrolysis in the presence of SPIONs and surfactant-coated SPIONs were carried out spectrophotometrically. The concentrations of OH− ions were taken in excess over [procaine] to keep the reaction conditions under pseudo-first-order. The presence of SPIONs and the SPIONs coated with cetyltrimethylammonium bromide; CTABr and sodium dodecylsulphate; SDS surfactants displayed an inhibitive effect on the rate of hydrolysis of procaine. The synthesised nanoparticles were characterised using X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). The kψ-[surfactant] profile in the presence of SPIONs was discussed using the pseudophase model in which the reactants are considered to be distributed in the aqueous and micellar media. The rate constant for the procaine hydrolysis and the binding constants of procaine with coated and non-coated SPIONs have been calculated by analysing the data for the variation in the rate constant with the change in [surfactant], [SPIONs] and [surfactant-coated SPIONs]. The studies on the rate of hydrolysis of procaine in the presence of SPIONs and surfactant-coated SPIONs shows inhibitive effects of NPs on the reaction. Procaine has good binding affinity with surfactant-coated SPIONs in comparison with the bare SPIONs.