Nanoemulsion Formulations of Fungicide Tebuconazole for Agricultural Applications

Tebuconazole (TBZ) nanoemulsions (NEs) were formulated using a low energy method. TBZ composition directly affected the drop size and surface tension of the NE. Water fraction and the organic-to-surfactant-ratio (R(O/S)) were evaluated in the range of 1–90 and 1–10 wt %, respectively. The study was carried out with an organic phase (OP) consisting of an acetone/glycerol mixture containing TBZ at a concentration of 5.4 wt % and Tween 80 (TW80) as a nonionic and Agnique BL1754 (AG54) as a mixture of nonionic and anionic surfactants. The process involved a large dilution of a bicontinuous microemulsion (ME) into an aqueous phase (AP). Pseudo-ternary phase diagrams of the OP//TW80//AP and OP//AG54//AP systems at T = 25 °C were determined to map ME regions; these were in the range of 0.49–0.90, 0.01–0.23, and 0.07–0.49 of OP, AP, and surfactant, respectively. Optical microscope images helped confirm ME formation and system viscosity was measured in the range of 25–147 cP. NEs with drop sizes about 9 nm and 250 nm were achieved with TW80 and AG54, respectively. An innovative low-energy method was used to develop nanopesticide TBZ formulations based on nanoemulsion (NE) technology. The surface tension of the studied systems can be lowered 50% more than that of pure water. This study’s proposed low-energy NE formulations may prove useful in sustainable agriculture.