Preparation and characterization of imidacloprid lignin-polyethylene glycol matrices coated with ethylcellulose.
Imidacloprid, a systemic insecticide that has a water solubility of 610 mg L(-1), has been formulated in lignin-polyethylene glycol matrices by a melting process. This formulation was coated in a Wurster type fluidized-bed equipment using ethylcellulose and dibutyl sebacate. Imidacloprid has been entrapped, with an entrapment efficiency higher than 87% in all cases. Thermogravimetric analysis, differential scanning calorimetry, and Fourier transformed infrared spectroscopy studies indicate the stability and compatibility of polymers and imidacloprid. Scanning electron microscopy images show a homogeneous film of ethylcellulose in coated formulations. From T(50) values (the time taken for 50% of the active ingredient to be released into water), the release rate of imidacloprid is controlled by changing the thickness of the coating film and modifying its surface properties by adding a plasticizer. T(50) values, ranging from 3.02 to 168.6 h, allow supplying the appropriate amount of imidacloprid in each specific agronomic practice to increase the efficiency of this bioactive material and minimize the risk of environmental pollution.
Department of Inorganic Chemistry, University of Almería, Campus de Excelencia Internacional Agroalimentario (ceiA3), La Cañada de San Urbano s/n, Almería.
Francisco
F
Flores-Céspedes
Cristina Isabel
CI
Figueredo-Flores
Isabel
I
Daza-Fernández
Fernando
F
Vidal-Peña
Matilde
M
Villafranca-Sánchez
Manuel
M
Fernández-Pérez
D002482:Cellulose / Q000031:analogs & derivatives* / Q000737:chemistry; D055598:Chemical Phenomena; D003692:Delayed-Action Preparations / Q000138:chemical synthesis; D007093:Imidazoles / Q000008:administration & dosage* / Q000009:adverse effects / Q000737:chemistry; D007306:Insecticides; D008031:Lignin / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D000073943:Neonicotinoids; D009574:Nitro Compounds / Q000008:administration & dosage* / Q000009:adverse effects / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D014867:Water / Q000737:chemistry; D014877:Water Pollution, Chemical / Q000517:prevention & control
D003692:Delayed-Action Preparations; D007093:Imidazoles; D007306:Insecticides; D000073943:Neonicotinoids; D009574:Nitro Compounds; D011108:Polymers; D014867:Water; C082359:imidacloprid; D011092:Polyethylene Glycols; C013517:ethyl cellulose; D002482:Cellulose; D008031:Lignin