Fabrication of acrylic acid grafted guar gum-multiwalled carbon nanotube hydrophobic membranes for transdermal drug delivery

Environmentally stable acrylic acid (AA) grafted guar gum (GG)-carboxy functionalized multiwalled carbon nanotube (f-MWCNT) in situ composite membranes for the sustained release of a hydrophobic drug, namely, diclofenac sodium, have been developed and characterized. Absolute matrix-filler interaction, particularly up to 1 wt% f-MWCNT concentration, instigated finer dispersion of the filler and subsequent increase in the water resistance and drug retention properties of the composites compared to the 2 and 3 wt% levels. The latter showed non-uniform filler networking and eventually resulted in poor water resistance and drug retention behaviors. The slowest drug release was achieved at the 1 wt% f-MWCNT level and fastest was observed at 3 wt% (21.5% vs. 48.5%). The releases followed a non-Fickian mechanism with the greater influence of viscoelastic relaxation at 0.5 and 1 wt% compositions compared to 2 and 3 wt% compositions, respectively.