Fig. 1.

Drug particles in the hydrogels. a FESEM photograph of freshly prepared nanosize drug-loaded gel (with triethanolamine) showing uniformly distributed drug particles of size, 10 nm. b Light microscope picture of freshly prepared hydrogel with microsized drug particle (with triethanolamine). c FESEM photograph of nanosize drug loaded hydrogel (with triethanolamine) upon storage of the samples at 4°C. d FESEM photograph of nanosize drug loaded hydrogel (with triethanolamine) upon storage of the samples at 25°C and 60% RH. e SEM of nanosize drug loaded hydrogel (with triethanolamine) upon storage of the samples at 40°C and 75% RH