Liquid chromatographic determination of florfenicol in the plasma of multiple species of fish

Quantification and Analysis of Trace Levels of Phenicols in Feed by Liquid Chromatography–Mass Spectrometry

A sensitive and reliable method using liquid chromatography–negative electrospray ionization mass spectrometry was developed for the simultaneous determination of chloramphenicol, florfenicol, and thiamphenicol at trace levels in animal feed. The analytes were extracted from grinded feed with ethyl acetate. Further the ethyl acetate was evaporated, residue resuspended in Milli-Q water, defatted with n-hexane, and solid phase extracted using BondELUT C18 cartridges. Separation was carried out on a C6 phenyl column with a mobile phase consisting of 0.1% formic acid in Milli-Q water and acetonitrile. The detector response was linear over the tested concentration range from 100 to 1000 µg kg−1. The recovery values for all analytes in feed were higher than 79% with RSD for repeatability and reproducibility in the ranges of 4.5–10.9% and 8.4–13.5%, respectively. CCα and CCβ varied between 76.8 and 86.1 µg kg−1, and between 111.3 and 159.9 µg kg−1, respectively. The results showed that this method is effective for the quantification of phenicols in non-target feed.

Development and Characterization of Florfenicol-Loaded BSA Nanoparticles as Controlled Release Carrier

Florfenicol (FLO) is a broad-spectrum fluorinated antibiotic used for the treatment of bacterial diseases such as bovine respiratory disease (BRD) in cattle. FLO is a poorly soluble drug in aqueous solution, and its encapsulation in various nanovehicles has been reported to be less than 30%. In this context, the use of bovine serum albumin (BSA) as a nanocarrier for FLO is an interesting approach. BSA is a biocompatible, biodegradable, nontoxic, and nonimmunogenic natural protein, allowing the vehiculization of hydrophilic and hydrophobic drugs with a well-tolerated administration. The present work focuses on the fabrication and characterization of florfenicol-loaded BSA (FLO-BSA NPs), incorporation efficiency, and in vitro release pattern. FLO-BSA NPs nanoparticles were successfully obtained by a simple, low-cost and in a few steps method. The physicochemical properties of the obtained nanoparticles such as size (~ 120 nm), polydispersity index (0.04), and zeta potential (approximately - 40 mV) suggest a high colloidal stability and suitable characteristics for drug delivery. The drug loading reveals a high incorporation of florfenicol in the nanoparticles, in which 33.6 molecules of FLO are encapsulated per each molecule of BSA. The in vitro release profile exhibits an initial stage characterized by the burst effect and then a prolonged release of FLO from the albumin matrix, which is compatible with the Higuchi model and which follows a Fickian diffusion. The results together suggest a suitable tool for future investigations in drug delivery field in order to use this nanomaterial in food, pharmaceutical, and veterinary industry.

Florfenicol residues in Nile tilapia after 10-d oral dosing in feed: effect of fish size

Nile tilapia Oreochromis niloticus were medicated with florfenicol (AQUAFLOR type A medicated article; Schering-Plough Animal Health, Summit, New Jersey) via a medicated ration at 15 mg florfenicol x kg fish body weight(-1) d(-1) for 10 d to compare the elimination kinetics of the test article in different size fish held at 25 degrees C. The groups of fish used in the study had mean weights of approximately 100, 250, and 500 g. In each trial, the fish were provided the medicated ration and 15 fish were processed at each of seven time points postfeeding for determination of the florfenicol concentration in serum and the florfenicol residue in the edible portion (composite muscle and skin). There was a trend toward shorter half-lives of elimination in the smaller fish. The elimination times in muscle-skin (times to reach the established tolerance concentration for channel catfish Ictalurus punctatus and salmonids of 1.0 microg florfenicol residue/g) and half-lives were 9.2 and 1.2 d (100 g), 8.6 and 1.7 d (250 g), and 12.7 and 2.2 d (500 g), respectively.

Florfenicol residues in three species of fish after 10-day oral dosing in feed

Nile tilapia Oreochromis niloticus, walleye Sander vitreus, and hybrid striped bass (female white bass Morone chrysops x male striped bass M. saxatilis) were medicated with florfenicol (AQUAFLOR type A medicated article; Schering-Plough Animal Health, Summit, New Jersey) via a medicated ration of 10 mg florfenicol x kg fish body weight(-1) d(-1) for 10 d to compare the elimination kinetics of the test article. This study was part of a larger effort in support of a species grouping concept that could contribute to the regulatory approval process for therapeutic compounds for cultured fishes. The trials in this study were conducted at the ideal water temperature for each species and at the temperature 5 degrees C lower than the ideal. The test temperatures were 30 degrees C and 25 degrees C for Nile tilapia, 25 degrees C and 20 degrees C for both walleyes and hybrid striped bass. In all cases, the elimination kinetics of florfenicol were more rapid at higher temperatures. The time to reach the tolerance of 1 microg/g in muscle-skin, as set by the U.S. Food and Drug Administration for channel catfish Ictalurus punctatus and salmonids, ranged from 6.1 to 4.1 d for Nile tilapia, from 12.6 to 9.7 d for walleyes, and from 2.6 to 0.7 d for hybrid striped bass at temperatures between 20 degrees C and 30 degrees C.

Acute toxicity of oxytetracycline and florfenicol to the microalgae Tetraselmis chuii and to the crustacean Artemia parthenogenetica

Aquaculture systems are a potentially significant source of antibacterial agents to the aquatic environment. The antibacterials oxytetracycline (OTC) and florfenicol (FLO) have been widely used in aquaculture. These pharmaceuticals may cause deleterious effects on wild aquatic organisms accidentally exposed to them. Therefore, the objective of this study was to evaluate the acute toxicity of OTC and FLO to the microalgae Tetraselmis chuii and to the crustacean Artemia parthenogenetica, using culture growth inhibition and death, respectively, as effect criteria. OTC and FLO were found to inhibit the growth of T. chuii cultures, with 96 h IC(50) values of 11.18 and 6.06 mg/L, respectively. OTC 24 and 48 h LC(50) values for A. parthenogenetica were 871 and 806 mg/L, respectively. FLO did not cause mortality of A. parthenogenetica. These results indicate that OTC and FLO are considerably more toxic to T. chui than to A. parthenogenetica. They also indicate that the concentrations required to induce mortality to A. parthenogenetica only in exceptional conditions will occur in the environment.

Comparative evaluation between capillary electrophoresis and high-performance liquid chromatography for the analysis of florfenicol in plasma

A capillary electrophoresis (CE) and a reversed phase high-performance liquid chromatography (RP-HPLC) method with UV detection have been developed for florfenicol analysis in plasma samples. The suitabilities of both methods for quantitative determination of florfenicol were approved through validation specification, such as linearity, precision, selectivity, accuracy, limit of detection and quantification. The capillary electrophoresis (CE) and high-performance liquid chromatography (HPLC) assay were compared by analyzing a series of plasma samples containing florfenicol in different concentrations using the two methods. The extraction procedure is simple and no gradient elution or derivatization is required. Furthermore, the analysis time of the CE method is two times shorter than the respective parameter in HPLC and solvent consumptions is considerably lower. The calibration curve were linear to at least 0.05-10 microg/ml (r = 0.9998) and 0.1-10 microg/ml (r = 0.9998) for CE and HPLC, respectively. The separation efficiency are good for both methods. The detection limits for florfenicol were 0.015 microg/ml with CE and 0.03 microg/ml with HPLC and CE method gave lower value, even though UV detector was applied in the both cases. The both methods were selective, robust and reliable quantification of florfenicol and can be useful for clinical and biomedical investigations.

Optimization and validation of a micellar electrokinetic chromatographic method for the analysis of florfenicol

We have optimized a micellar electrokinetic capillary chromatographic method for the separation of florfenicol and florfenicol amine, its degradation product. The separation was carried out using a 50mM sodium borate buffer (pH 9.0) containing 25mM of sodium dodecyl sulphate. The method selectivity was proven by the simultaneous separation of florfenicol and two structural antibiotics, chloramphenicol and thiamphenicol. The same system can also be applied for the quantitative determination of these antibiotics. The method was then validated regarding linearity, precision and accuracy.