RESUMEN
The microencapsulation and dissolution of undecenovanillylamide (I), a potential coyote-aversive agent for use on sheep, were studied. While I has been shown to protect sheep, its short duration of action makes it economically unfeasible. Compound I microcapsules were prepared, and optimum conditions for encapsulation via complex coacervation were determined. Microcapsules that were hardened for 0.5, 1, and 2 hr, as well as I powder, were characterized according to their dissolution. Longer hardening times resulted in slower release, with all encapsulated I forms being released slower than the powder. The dissolution t50 for unencapsulated powder was less than 3 min; for microcapsules hardened for 30 min, the dissolution t50 was 7.3 min; for those hardened 60 min, the t50 was 17.7 min; and for those hardened 120 min, the t50 was 28 min. The encapsulated I would have a longer field life and, therefore, might be a viable economic and ecologic answer to coyote protection for sheep.
