Poly (vinyl alcohol) and xanthan gum composite films for sustained releaseAuthor(s): Neeraj Dhar, Hema Setia, Anupama Thakur, R.K.Wanchoo
In the present work, films based on Poly(vinyl alcohol) (PVA) and composite films based on PVAand Xanthan Gum(XG) were synthesized in acidic, neutral and alkaline conditions using Epichlorohydrin as cross linker. The effect of pHduring synthesis and the ratio of PVA: XG in the composite film on the equilibrium swelling ratio of the composite films were investigated. The in vitro release study on the synthesized films was carried out at 7.4 pH and 37°C (±1°C) using uric acid as model drug. The swelling capabilities of PVA/XG composite films were found to be lesser than PVAfilms and the equilibrium swelling ratio decreased with an increase in the XG content in the composite films. It was observed that the films synthesized at pH<4.0 have a higher equilibrium swelling ratio as compared to those synthesized at pH 7-7.5 and pH >9.0. The observed experimental data on uric acid were fitted to different kinetic models available in the literature and based on the minimumrelative quadratic error it was found that the drug release data was well represented by first order kinetics.