Diclofenac Degradation Under High Pressure Hydrodynamic Cavitation Field

The pharmaceuticals products degradation via uv-assisted photosensitive nanoparticles showed several limits regarding to the yields and the toxicity of by-products. One of alternative less studied is the hydrodynamic cavitation where highly intensive mechanical energy transferred in a shock wave can be an opportunity to develop new technologies. In this paper, a hydrodynamic cavitation method for degradation of the diclofenac-sodium is presented. A plunger pump was uses for feeding a convergent nozzle with a throat diameter of 0.2 mm, which permit the development of high shear forces specific to hydrodynamic cavitation. Three values for the pressure at nozzle inlet were used: 10, 20, 37.5 MPa. A solution of 5g diclofenac powder, milled from tablets, in 50 ml of distilled water was prepared and exposed to cavitation submerged jets for 3 minutes. As-obtained samples were analyzed by UV-VIS spectroscopy for quantifying the conversion rate. The analysis of the samples showed a higher degree of diclofenac degradation as pressure increase −76% at 37.5 MPa - but low degradation gradient as pressure values are increasing.