(289h) Controlled Release of Insect Repellent from Biopolymer Core-Shell and Matrix Microcapsules

Natural insect repellents have gained attention in recent years as a safe method to combat the spread of vector-borne illnesses such as Malaria or Zika. However, these chemicals tend to evaporate at a rate far higher than is needed, requiring them to be reapplied every few hours. Consequently, harsher chemicals such as permethrin are still used when long-lasting repellency is required. The objective of this research is to encapsulate natural insect repellants in polymeric gels and matrices to achieve controlled release. The relation between the structure of the crosslinked gel and the diffusion rate will be studied by varying the thickness and the degree of crosslinking. Two separate methods of microencapsulation are being explored: a gelatin/gum arabic core-shell microcapsule using complex coacervation, and a gelatin matrix microcapsule using a solvation/dialysis method. The morphology, rheology, and diffusion rate of the insect repellant into different media are being studied. The methods used and the results obtained will be presented.

PAO #: U19-1079