Polymer hydrogel from carboxymethyl guar gum and carbon nanotube for sustained trans-dermal release of diclofenac sodium

Novel carboxymethyl guar gum (CMG)-chemically modified multiwalled carbon nanotube (MCNT) hybrid hydrogels were synthesized at different MCNT levels as potential device for sustained trans-dermal release of diclofenac sodium. Spectroscopy together with morphology, thermogravimetry, and theological studies proved relatively strong CMG-MCNT interaction at 0.5 and 1 wt% levels of MCNT whereas de-wetting was increased with higher MCNT concentration. Drug encapsulation tendency increased with addition of MCNT; maximum entrapment was noticed at 1 wt% MCNT level. Hydrogels containing 0.5, 1 and 3 wt% MCNT exhibited slower trans-dermal release than neat CMG due to slightly higher gel viscosity and more drug entrapment. Slowest but steady release was obtained from 1 wt% MCNT loaded hydrogel due to highest viscous resistance among all other hybrid nanocomposites. (C) 2011 Elsevier B.V. All rights reserved.