Dextrin Nanocomposites as Matrices for Solid Dosage Forms
- ACS Appl Mater Interfaces. 2020 Apr 8;12(14):16969-16977. doi: 10.1021/acsami.0c02061.
- 1. Department of Chemical Engineering, University of Pretoria, Private Bag X20, Hatfield, Pretoria 0028, South Africa.
- 2. Sefako Makgatho Health Sciences University, Ga-Rankuwa 0208,South Africa.
- 3. Department of Consumer and Food Sciences, University of Pretoria, Private Bag X20, Hatfield, Pretoria0028, South Africa.
Safe application of water-insoluble acaricides requires fast release from solid dosage systems into aquatic environments. Dextrin is a water-soluble form of partially hydrolyzed starch, which may be used as matrix material for these systems if retrogradation can be inhibited by the inclusion of nanofillers. Several glycerol-plasticized thermoplastic dextrin-based nanocomposites were prepared with a twin-screw extrusion-compounding process. The nanofillers included a layered double hydroxide (LDH), cellulose nanofibers (CNF), and stearic acid. The time-dependent retrogradation of the compounds was monitored by X-ray diffraction (XRD) and dynamic mechanical thermal analysis (DMA). XRD showed that composite samples that included stearic acid in the formulation led to the formation of an amylose-lipid complex and a stable crystallinity during aging. The most promising nanocomposite included both stearic acid and CNF. It was selected as the carrier material for the water-insoluble acaricide Amitraz. Fast release rates were observed for composites containing 5, 10, and 20% (w/w) of the pesticide. A significant reduction in the particle size of the released Amitraz powder was observed, which is ascribed to the high-temperature compounding procedure.