Many consumers seek long-ripening meat products. The availability of these highly distinctive cured pork varieties is continuously expanding and their safety should be subject to monitoring. One of potentially harmful substances in these products is histamine. The presence of this toxic amine is reported in many countries, even in high concentrations. However, the EU has not regulated the permissible histamine content in meat, in a situation at odds with that of regulated fish and fish products. This study established the usefulness of biogenic amine testing in long-ripening pork and furnished indicative concentrations potential useful as a background for future research in preparation for EU regulative intervention. A total of 97 samples of long-ripening meat products untreated by heat were bought from various shops in the Puławy and Lublin regions of Poland and tested for the presence of histamine using high-performance liquid chromatography with diode array. The histamine concentration ranged from below limit of detection to 346.64 mg/kg, where 3.47 mg/kg was the lowest in a positive sample. Histamine was detected in 48 samples (49.5%). The maximum amount of histamine was identified in dry ham and the minimum in traditional salami. The results of this study suggest that testing meat products for biogenic amines should be a very good indicator of the food safety of long-ripening meats. In half of the tested products, levels of biogenic amines potentially toxic to consumers were determined.

A high-performance liquid chromatographic–diode array detector (HPLC-DAD) method for the determination of amoxicillin in medicated feedingstuffs was developed and validated. The method was used to investigate the quality requirements of animal feedingstuffs (declared content of active substance and feed homogeneity). Two-gram samples were extracted by potassium phosphate buffer solution. Extracts were filtered and directly analysed by HPLC-DAD without further clean-up. Amoxicillin was separated by acetonitrile and 0.01M phosphate buffer (pH 5.0) on a Phenomenex Luna C18 column. This method provided average recoveries of 76.1 to 81.6% with coefficients of variation (CV, %) for repeatability and reproducibility in the ranges of 3.7–7.2% and 5.3–7.6%, respectively. The limit of detection was 51.2 mg/kg and limit of quantification was 103.0 mg/kg. The method was successfully validated and proved to be efficient, precise, and useful for quantification of amoxicillin in medicated feedingstuffs.

Introduction: Quercetin is a polyphenolic flavonoid which has been used in traditional Chinese medicine as a natural therapeutic agent with a broad spectrum of activities (antioxidant, anticancer, neuroprotective, anti-inflammatory, antiviral and antibacterial). The aim of this study was to develop and validate a rapid and simple ultra-high-performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) method for the determination of quercetin in milk. Material and Methods: Sample preparation was based on a liquid-liquid extraction with 0.5% formic acid in acetonitrile. The chromatographic separation was performed on a ZORBAX SB-C18 column with methanol and 0.5% formic acid as a mobile phase. Results: The procedure was successfully validated. The mean recovery of the analyte was 98%, with the corresponding intra- and inter-day variation less than 10% and 15%, respectively, and the repeatability and reproducibility were in the range of 3%–7.2% and 6.1%–12%, respectively. The lowest level of quantification was 1.0 μg/kg. Conclusion: The proposed method was successfully applied in evaluating the pharmacokinetics of quercetin in milk obtained from dairy cows with clinical mastitis after intramammary administration.

A high-performance liquid chromatographic–diode array detector (HPLC-DAD) method for the determination of amoxicillin in medicated feedingstuffs was developed and validated. The method was used to investigate the quality requirements of animal feedingstuffs (declared content of active substance and feed homogeneity).

Histamine is one of the most important and toxic biogenic amines which may be present in food and may cause food poisoning in humans when contained at a high level. It is produced during bacterial decarboxylation of histidine in fish muscles. The aim of the study was to investigate the presence of histamine in fish and fish products available in Poland during 2014–2018. A total of 421 samples of raw (248), smoked (107), canned (50), and marinated fish (16) were analysed by high-performance liquid chromatography with diode array detection. Histamine was detected in 14.1% samples of raw fish, 29% of smoked fish, 22% of canned fish and 93.8% of marinated fish in concentrations ranging from 3.4 to 156.4 mg/kg. Content of this amine above 100 mg/kg was found in four samples: raw Atlantic salmon, smoked European sprat and two samples of marinated Atlantic herring. The study showed that fish and fish products on the Polish market generally meet the food safety criteria for histamine and are safe for consumers.

OBJECTIVE To determine the pharmacokinetics of enrofloxacin after IV administration in American black vultures (Coragyps atratus), to compare clearance of enrofloxacin in American black vultures with clearance of this fluoroquinolone in other avian species, and to evaluate whether allometric scaling is an appropriate tool for dose extrapolation in avian species. ANIMALS 6 healthy adult American black vultures. PROCEDURES Enrofloxacin concentrations were quantified by use of high-performance liquid chromatography. Pharmacokinetics of enrofloxacin was determined in American black vultures after IV administration. Pharmacokinetic parameters for 12 avian species obtained from 24 pharmacokinetic studies were used. Allometric analysis of enrofloxacin pharmacokinetic parameters was performed. RESULTS Volume of distribution at steady state for enrofloxacin was 3.47 L/kg, clearance was 0.147 L/h·kg, and elimination half-life was 18.3 hours. Comparisons among avian species revealed that American black vultures had the lowest extraction ratio for enrofloxacin (1.04%). Only the volume of distribution at steady state and clearance had a good allometric fit. Goodness of fit was improved when ratites were not included in the analysis. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that the use of allometric scaling for the prediction of volume of distribution at steady state could provide a suitable method for extrapolation of enrofloxacin doses among avian species; however, allometric scaling could not be used to adequately predict the clearance of enrofloxacin.

OBJECTIVE To determine the pharmacokinetics of levofloxacin following oral administration of a generic levofloxacin tablet and IV administration to dogs and whether the achieved plasma levofloxacin concentration would be sufficient to treat susceptible bacterial infections. ANIMALS 6 healthy adult Beagles. PROCEDURES Levofloxacin was administered orally as a generic 250-mg tablet (mean dose, 23.7 mg/kg) or IV as a solution (15 mg/kg) to each dog in a crossover study design, with treatments separated by a minimum 2-day washout period. Blood samples were collected at various points for measurement of plasma levofloxacin concentration via high-pressure liquid chromatography. Pharmacokinetic analysis was performed with compartmental modeling. RESULTS After oral administration of the levofloxacin tablet, mean (coefficient of variation) peak plasma concentration was 15.5 μg/mL (23.8%), mean elimination half-life was 5.84 hours (20.0%), and mean bioavailability was 104% (29.0%). After IV administration, mean elimination half-life (coefficient of variation) was 6.23 hours (14.7%), systemic clearance was 145.0 mL/kg/h (22.2%), and volume of distribution was 1.19 L/kg (17.1%). CONCLUSIONS AND CLINICAL RELEVANCE In these dogs, levofloxacin was well absorbed when administered orally, and a dose of approximately 25 mg/kg was sufficient to reach pharmacokinetic-pharmacodynamic targets for treating infections with susceptible Enterobacteriaceae (ie, ≤ 0.5 μg/mL) or Pseudomonas aeruginosa (ie, ≤ 1 μg/mL) according to clinical breakpoints established by the Clinical and Laboratory Standards Institute.

OBJECTIVE To determine plasma concentrations of lidocaine after laryngeal administration or laryngeal and intratesticular administration in cats. ANIMALS 14 healthy adult sexually intact male cats (7 cats/treatment). PROCEDURES Cats were randomly allocated to receive 0.1 mL of 2% or 10% lidocaine hydrochloride solution (treatments L2 and L10, respectively) sprayed on the larynx for laryngeal desensitization, followed by endotracheal intubation and isoflurane anesthesia. After a 7-day washout period, cats were again randomly allocated to receive treatment L2 or L10, and castration was performed under isoflurane anesthesia following intratesticular administration of 2% lidocaine solution (0.1 mL/kg). In both experiments, a blood sample for measurement of plasma lidocaine concentration was obtained before (0 minutes) and 3, 5, 10, 15, 20, 30, 45, 60, and 75 minutes after laryngeal administration of lidocaine solution. Anesthesia was discontinued at 60 minutes. Plasma lidocaine concentrations were measured with high-performance liquid chromatography. RESULTS After treatments L2 and L10, median maximum plasma lidocaine concentrations were 34.1 ng/mL (range, 0 to 279.4 ng/mL) and 93.6 ng/mL (range, 79.3 to 182.2 ng/mL), respectively. Time to maximum plasma concentration was 10 minutes (range, 0 to 20 minutes) for each treatment. When cats received intratesticular lidocaine administration following L2 or L10 treatment, median maximum plasma concentration was 181.0 ng/mL (range, 103.7 to 600.2 ng/mL) and 301.2 ng/mL (range, 265.8 to 1,770.0 ng/mL), respectively. CONCLUSIONS AND CLINICAL RELEVANCE On the basis of these data, combined laryngeal and intratesticular administration of lidocaine solution at a total dose of approximately 5 mg/kg appears to be safe for use in healthy adult cats.

OBJECTIVE To evaluate pharmaceutical characteristics (strength or concentration, accuracy, and precision), physical properties, and bacterial contamination of fluconazole compounded products. SAMPLE Fluconazole compounded products (30- and 240-mg capsules; 30- and 100-mg/mL oral suspensions) from 4 US veterinary compounding pharmacies. PROCEDURES Fluconazole compounded products were ordered 3 times from each of 4 pharmacies at 7- or 10-day intervals. Generic fluconazole products (50- and 200-mg tablets; 10- and 40-mg/mL oral suspensions) served as references. Compounded products were evaluated at the time of receipt; suspensions also were evaluated 3 months later and at beyond-use dates. Evaluations included assessments of strength (concentration), accuracy, precision, physical properties, and bacterial contamination. Acceptable accuracy was defined as within ± 10% of the labeled strength (concentration) and acceptable precision as within ± 10%. Fluconazole was quantified by use of high-performance liquid chromatography. RESULTS Physical characteristics of compounded products differed among pharmacies. Aerobic bacterial cultures yielded negative results. Capsules (30 and 240 mg) had acceptable accuracy (median, 96.3%; range, 87.3% to 135.2%) and precision (mean ± SD, 7.4 ± 6.0%). Suspensions (30 and 100 mg/mL) had poor accuracy (median, 73.8%; range, 53.9% to 95.2%) and precision (mean ± SD, 15.0 ± 6.9%). Accuracy and precision were significantly better for capsules than for suspensions. CONCLUSIONS AND CLINICAL RELEVANCE Fluconazole compounded products, particularly suspensions, differed in pharmaceutical and physical qualities. Studies to evaluate the impact of inconsistent quality on bioavailability or clinical efficacy of compounded fluconazole products are indicated, and each study should include data on the quality of the compounded product evaluated.

OBJECTIVE To determine the pharmacokinetics of meloxicam in domestic hens and duration and quantity of drug residues in their eggs following PO administration of a single dose (1 mg of meloxicam/kg). ANIMALS 8 healthy adult White Leghorn hens. PROCEDURES Hens were administered 1 mg of meloxicam/kg PO once. A blood sample was collected immediately before and at intervals up to 48 hours after drug administration. The hens' eggs were collected for 3 weeks after drug administration. Samples of the hens' plasma, egg whites (albumen), and egg yolks were analyzed by high-performance liquid chromatography. RESULTS The half-life, maximum concentration, and time to maximum concentration of meloxicam in plasma samples were 2.8 hours, 7.21 μg/mL, and 2 hours, respectively. Following meloxicam administration, the drug was not detected after 4 days in egg whites and after 8 days in egg yolks. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that meloxicam administered at a dose of 1 mg/kg PO in chickens appears to maintain plasma concentrations equivalent to those reported to be therapeutic for humans for 12 hours. The egg residue data may be used to aid establishment of appropriate drug withdrawal time recommendations.