The purpose of this study was to examine the capacity of live brine shrimp Artemia spp. to accumulate
metronidazole at different developmental life stages.
Metronidazole is used in fish as an
antiparasitic medication. An effective
drug delivery method is to enrich the Artemia with
metronidazole and offer them as live feed to the infected fish, usually ornamental species and other small fishes. Artemia
cysts were hatched and then soaked in a
metronidazole solution (0.05%) at instars 1-3 of larval development. Our findings indicated that Artemia were able to accumulate
metronidazole at levels considered therapeutic to other animals and humans (25-100 mg/kg). However, the levels varied depending on the stage of larval development. Artemia accumulated the highest levels of
metronidazole (137-143 mg/kg) when they started filter feeding (instar 2), whereas newly hatched Artemia (instar 1) contained the lowest level (85 mg/kg). Based on this study and a review of the literature, a new protocol recommended for enriching Artemia with
metronidazole consists of soaking the Artemia in a 0.05%
metronidazole solution for 3 h at room temperature. Because
metronidazole is relatively insoluble in water, it must first be dissolved in warm water with continuous stirring.