Rheological studies on solid lipid nanoparticle based carbopol gels of aceclofenac.

Solid lipid nanoparticles (SLN) of aceclofenac were prepared using Taguchi experimental design by Trotta method. The prepared SLN were formulated into a gel preparation, using carbopol 940. Gels were evaluated for drug content, bioadhesion and their stability against change of temperature and shear. The viscosity of prepared gels was found to be temperature independent. Rheological behavior of gels with changing shear was rather complex. Viscosity varied inversely with shear but remained almost constant during short spans of time when shear was kept constant. Viscosity of the gels did not change if shear was not varied. In vitro diffusion studies exhibited an immediate release followed by a sustained release. This could help in maintaining the concentration of bioactives such as aceclofenac in desirable levels at sites of inflammation and injury.