RESUMO
We aimed to assess guar and xantban gum based floating drug delivery system containing mefenamic acid. Floating tablets of nefenamic acid were formulated with different concentrations of guar and xanthan gum via wet granulation method. The flow properties of granules that is: bulk density, tapped density, flow rate, Carr index, Hausner's ratio, compressibility index and angle of repose as well as physical parameters of the compressed tablets including: hardness, friability, thickness and swelling indices were determined and found to be good. Xanthan gum was superior to guar gum in maintaining drug release, but a combination of polymers was found to be the best for achieving sustained release up to 12 h due to the synergistic effect of both gums. Drug release mechanism was best explained by Korsmeyer-Peppas model. Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) studies showed absence of any visible interaction. Stability studies at 40°C (75% RH) showed that the formulation was stable at elevated temperature. It can be concluded that floating tablets can be used as a sustained release matrix due to their superior characteristics.
