Microemulsions of tribenuron-methyl using Pluronic F127: Physico-chemical characterization and efficiency on wheat weed

Microemulsions have received particular interest as novel vehicles for drug delivery. Herein, a new tribenuronmethyl (TM) loaded oil-in-water Pluronic F127-stabilized microemulsion is developed as a promising delivery nanocarrier for herbicides to control the growth of wheat weed (Convolvulus arvensis). The diameter for the TM-loading microemulsions was determined to be 7.5 nm. Experimental results revealed a high entrapment (83% +/- 6%) and loading efficiency (0.44% +/- 0.07%) of TMin F127-stabilized microemulsions. The in-vitro release profile from the microemulsions ensured a controlled and sustained release of the loaded TM, with ca. 50% release of TM was achieved from the microemulsions within the first 35 h, in comparison to a complete release of free TM within the first 5 h. After 5 weeks, TM-microemulsions were able to reduce the fresh weight (76%), dry weight (55%), acetolactate synthase activity (83%), and plant height (79%) of C. arvensis in comparison with controls. Using a herbicide concentration as low as ca. 50% [15 g of active ingredient per hectare,g a.i. ha(-1))], of the recommended dose of commercial herbicides (Granstar) great inhibitions of weed growth were obtained. Therefore, the present microemulsion system opens the door to new nanocarriers for effective weed control to reduce economic costs and potential pollution issues. (C) 2020 Elsevier B.V. All rights reserved.