Preparation and characterization of PEG-Mentha oil nanoparticles for housefly control.

Nanoparticles of Mentha × piperita essential oil were prepared by melt-dispersion method. The nanoparticles prepared at varying oil doses (5-10%, w/v) showed an encapsulation efficiency of 78.2-83.4%, while the oil load was observed to range between 3.64 and 7.46%. The average particle size of the nanoparticles varied between 226 and 331 nm, while polydispersity index showed variation between 0.547 and 1.000. DSC analysis indicated endothermic reaction during formation of nanoparticles, while a 2-term exponential kinetic model was followed during oil release. Nanoparticles showed considerable mortality against housefly larvae in lab (100%) as well as simulated field condition after first week (93%) and 6th week (57%) of application. This was the first study utilizing controlled release property of nanoparticles to formulate a cost effective product for breeding site application against housefly.