Effects of formulation on the palatability and efficacy of in-feed Praziquantel medications for marine finfish

Authors

Edith K. Y. Tang, University of Western Australia, Perth, Western Australia
Gavin J. Partridge, Department of Primary Industries and Regional Development, Fremantle, Western Australia
Lindsey D. Woolley, Department of Primary Industries and Regional Development, Fremantle, Perth, Western AustraliaFollow
Luke Pilmer, Department of Primary Industries and Regional Development, Fremantle, Western AustraliaFollow
Lee Yong Lim, University of Western Australia, Perth, Western Australia

Document Type

Article

Publication Date

5-13-2022

Journal Title

Marine Drugs

ISSN

eISSN 1660-3397

Keywords

Praziquantel; Yellowtail kingfish; Agar; Chitosan; Alginate; Palatability; Efficacy

Abstract

Praziquantel (PZQ) provides an effective treatment against monogenean parasitic infestations in finfish. However, its use as an in-feed treatment is challenging due to palatability issues. In this study, five formulations of PZQ beads (1–4 mm) were developed using marine-based polymers, with allicin added as a flavouring agent. All formulations attained PZQ loading rates ≥74% w/w, and the beads were successfully incorporated into fish feed pellets at an active dietary inclusion level of 10 g/kg. When tested for palatability and digestibility in small yellowtail kingfish, the PZQ-loaded beads produced with alginate-chitosan, alginate-Cremophor® RH40, and agar as carriers resulted in high consumption rates of 99–100% with no digesta or evidence of beads in the gastrointestinal tract (GIT) of fish fed with diets containing either formulation. Two formulations produced using chitosan-based carriers resulted in lower consumption rates of 68–75%, with undigested and partly digested beads found in the fish GIT 3 h post feeding. The PZQ-loaded alginate-chitosan and agar beads also showed good palatability in large (≥2 kg) yellowtail kingfish infected with gill parasites and were efficacious in removing the parasites from the fish, achieving >90% reduction in mean abundance relative to control fish (p < 0.001). The two effective formulations were stable upon storage at ambient temperature for up to 18 months, showing residual drug content >90% compared with baseline levels. Overall, the palatability, efficacy and stability data collected from this study suggest that these two PZQ particulate formulations have potential applications as in-feed anti-parasitic medications for the yellowtail kingfish farming industry.

Recommended Citation

Tang, E. K. Y., Partridge, G. J., Woolley, L. D., Pilmer, L., & Lim, L. Y. (2022). Effects of Formulation on the Palatability and Efficacy of In-Feed Praziquantel Medications for Marine Finfish Aquaculture. Marine Drugs, 20(5), 323. https://doi.org/10.3390/md20050323