Synthesis and characterization of polyacrylamide/sodium carboxymethyl cellulose/montmorillonite nanocomposite hydrogel vaginal ring for drug delivery systems

Abstract

This research developed a hydrogel vaginal ring consisting of polyacrylamide (AAm), sodium carboxymethylcellulose (NaCMC) for vaginal drug delivery. To improve the swelling behaviour of vaginal ring, different concentrations of NaCMC were utilized. The results indicated that 0.1 g NaCMC had the highest amount of swelling. However, by increasing the swelling characteristic of vaginal ring, a low strength hydrogel was obtained. Therefore, N,N'-methylenebisacrylamide (MBA) was applied to the hydrogel in order to study the effect of cross-linker on prepared polymer efficiency and swelling properties. By adding of MBA within vaginal ring network, sufficient stability as well as proper swelling properties was obtained. It was found that vaginal ring composed of 0.1 g NaCMC and 0.02 g MBA showed the optimum swelling and suitable structure stability. In addition, montmorillonite (MMT) was added to the blank hydrogel (AAm/NaCMC) to investigate its effect on drug delivery in the simulated vaginal environment (pH= 4- 4.5). Both blank and nanocomposite vaginal rings were loaded with methylene blue (MB) as a modelled drug. The vaginal rings were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), Xray Diffraction (XRD) and Nuclear Magnetic Resonance (NMR). In vitro release behavior of MB illustrated that incorporation of MMT into vaginal ring controlled the drug delivery. It was found that by changing the concentration of MMT from 0.007 g to 0.01 gr, the drug release was prolonged for 15 days by reducing the initial drug release. According to the results, AAm/NaCMC/MMT nanocomposite hydrogel vaginal rings can be considered as good candidates for the vaginal drug delivery