The use of the polychaete worm Nereis virens eggs as vehicle for the delivery of oxytetracycline in Solea solea larvae

The eggs of the polychaete worm Nereis virens were used as a vehicle for the delivery of oxytetracycline (OTC) in Dover sole, Solea solea larvae. The eggs were osmotically loaded, and the level of antibiotic was estimated by HPLC and a microbiological bioassay. The amount of OTC in the N. virens eggs was over 1 μg per egg, which was considered more than sufficient for a therapeutic dose for larval fish. The loaded eggs were tested on the sole larvae, and the results of the experiment (9 μg OTC per fish larva) indicated that the eggs of the Nereis worm can be used as biocarriers of water soluble drugs.