title: Development and pharmacokinetic evaluation of erythromycin lipidic formulations for oral administration in rainbow trout (Oncorhynchus mykiss).
abstract: The aim of this work was to enhance the bioavailability of erythromycin base when administered orally in rainbow trout (Oncorhynchus mykiss). Since erythromycin is normally given in the form of medicated feed, in this study three new types of feed formulation were developed. A self-emulsifying system and two types of double microemulsions (O/W/O) were prepared, characterized and adsorbed on a commercial extruded diet for fish. The emulsified systems were based on saturated polyglycolized glycerides and mono- and diglycerides of medium-chain fatty acids (as oily phase), Tween 80 (as surfactant) and, in the case of double microemulsions, distilled water. The systems differed in percentage composition and for the amount and position of erythromycin in different phases. The three medicated feed were then administered orally by means of a gastric probe to rainbow trout and their relative bioavailability was estimated in comparison with that obtained after oral administration of feed with erythromycin powder. For each medicated feed, 80 fish were tested. Finally, plasma profiles of erythromycin after single administration of medicated feeds were used to predict profiles obtainable by administering once-daily medicated feeds for 7 consecutive days. The results proved that the feeds containing microemulsified erythromycin provided largely superior oral bioavailability and the advantage of obtaining the same efficacy against bacterial infections with a much lower dose of drug.
authors.affiliation: Department of Chemical and Pharmaceutical Sciences, University of Trieste, Trieste, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Serdoz
authors.forename: Dario
authors.initials: D
authors.lastname: Voinovich
authors.forename: Beatrice
authors.initials: B
authors.lastname: Perissutti
authors.forename: Iztok
authors.initials: I
authors.lastname: Grabnar
authors.forename: Dritan
authors.initials: D
authors.lastname: Hasa
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Ballestrazzi
authors.forename: Ettore
authors.initials: E
authors.lastname: Coni
authors.forename: Enrico
authors.initials: E
authors.lastname: Pellegrini
mesh_terms: D000284:Administration, Oral; D000821:Animal Feed; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000737:chemistry* / Q000493:pharmacokinetics*; D017756:Aquaculture; D004334:Drug Administration Schedule; D004339:Drug Compounding; D016503:Drug Delivery Systems; D015195:Drug Design; D004355:Drug Stability; D004655:Emulsions / Q000737:chemistry; D004917:Erythromycin / Q000008:administration & dosage / Q000737:chemistry* / Q000493:pharmacokinetics*; D005079:Excipients / Q000737:chemistry; D005227:Fatty Acids / Q000737:chemistry; D008055:Lipids / Q000737:chemistry; D008956:Models, Chemical; D017686:Oncorhynchus mykiss; D012995:Solubility; D014280:Triglycerides / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D004655:Emulsions; D005079:Excipients; D005227:Fatty Acids; D008055:Lipids; D014280:Triglycerides; D004917:Erythromycin