Preliminary Evaluation of Diclofenac Gel and Emulgel Formulated using Bentonite as a Gelling Agent

In this work, a bentonite from Maghnia (northwestern Algeria) was used as a gelling agent in gel and emulgel formulations. The percentage of Na-bentonite in the formulations was fixed at 5%. The physical appearance of the formulated gel and emulgel was characterized before determining their pH, viscosity and swelling index. A rheological analysis demonstrated the characteristic shear thinning and viscoelastic behavior of the formulations using thixotropy. Stability studies showed that the physical appearance and rheological properties of the prepared gel and emulgel remained unchanged having been stored for 3 months. An FTIR study proved that the drug and excipients are compatible with each other. The prepared formulations exhibited acceptable physical properties as well as levels of homogeneity, consistency and viscosity. The pH fell within an acceptable range of 6.40-6.80.