Pharmacokinetic Behaviour of Enrofloxacin after Single Intramuscular Dosage in American Black Vultures (Coragyps atratus).

The aim of the study was to investigate the intramuscular pharmacokinetics of enrofloxacin in black vultures (Coragyps atratus). The pharmacokinetics of a single intramuscular dose (10 mg/kg) of enrofloxacin was studied in six vultures. Plasma concentrations of enrofloxacin and its active metabolite, ciprofloxacin, were determined by high-performance liquid chromatography (HPLCuv). Pharmacokinetic parameters were estimated using non-compartmental and compartmental analysis. After intramuscular administration, enrofloxacin showed a rapid and complete absorption, reaching a Cmax value of 3.26 ± 0.23 µg/mL at 1.75 ± 0.53 h. A long terminal half-life of 19.58 h has been observed. Using previously published MIC values to perform a PK/PD analysis, cumulative fraction responses obtained after Monte Carlo simulation for AUC/MIC > 30, 50 and 125 were 72.93%, 72.34% and 30.86% for E. coli and 89.29%, 88.89% and 58.57% for Mycoplasma synoviae, respectively. Cumulative fraction responses obtained for Cmax/MIC index were 33.93% and 40.18% for E. coli and M. synoviae, respectively. The intramuscular administration of 10 mg/kg could be appropriate to treat infectious diseases caused by gram-positive bacteria with MIC value lower than 1 µg/mL; however, although enrofloxacin showed a slow elimination in black vultures, plasma concentrations were insufficient to reach the gram-negative stablished breakpoints.

Antileishmanial efficacy and tolerability of combined treatment with non-ionic surfactant vesicle formulations of sodium stibogluconate and paromomycin in dogs.

Infection with Leishmania infantum causes the disease visceral leishmaniasis (VL), which is a serious clinical and veterinary problem. The drugs used to treat canine leishmaniasis (CanL) do not cause complete parasite clearance; they can be toxic, and emerging drug resistance in parasite populations limits their clinical utility. Therefore, in this study we have evaluated the toxicity and efficacy of joint treatment with a 1:1 mixture of sodium stibogluconate-NIV (SSG-NIV, 10 mg Sbv/day) and paromomycin-NIV (PMM-NIV, 10 mg PMM/kg/day), given intravenously daily for seven days from day 270 post-infection, to nine-month-old female beagle dogs (n = 6) experimentally infected with Leishmania infantum. Treatment significantly improved the clinical symptoms of VL infection in all the treated dogs, reduced parasite burdens in lymph nodes and bone marrow, and all symptomatic treated dogs, were asymptomatic at 90 days post-treatment. Treatment was associated with a progressive and significant decrease in specific IgG anti-Leishmania antibodies using parasite soluble antigen (p < 0.01) or rK39 (p < 0.01) as the target antigen. In addition, all dogs were classified as parasite negative based on Leishmania nested PCR and quantitative real time PCR tests and as well as an inability to culture of promastigote parasites from lymph nodes and bone marrow tissue samples taken at day 90 post-treatment. However, treatment did not cure the dogs as parasites were detected at 10 months post-treatment, indicating that a different dosing regimen is required to cause long term cure or prevent relapse.

Coffee Silverskin Extract: Nutritional Value, Safety and Effect on Key Biological Functions.

This study aimed to complete the scientific basis for the validation of a coffee silverskin extract (CSE) as a novel food ingredient according to European legislation. Nutritional value, safety, effects on biochemical biomarkers and excretion of short chain fatty acids (SCFAs) in vivo of CSE were assessed. Proteins, amino acids, fat, fatty acids, fiber, simple sugars and micronutrients were analyzed. For the first time, toxicological and physiological effects were evaluated in vivo by a repeated-dose study in healthy Wistar rats. Hormone secretion, antioxidant (enzymatic and no-enzymatic) and anti-inflammatory biomarkers, and dietary fiber fermentability of CSE (analysis of SCFAs in feces) were studied in biological samples. This unique research confirms the feasibility of CSE as a human dietary supplement with several nutrition claims: "source of proteins (16%), potassium, magnesium, calcium and vitamin C, low in fat (0.44%) and high in fiber (22%)". This is the first report demonstrating that its oral administration (1 g/kg) for 28 days is innocuous. Hormone secretion, antioxidant or anti-inflammatory biomarkers were not affected in heathy animals. Total SCFAs derived from CSE fiber fermentation were significantly higher (p < 0.05) in male treated rats compared to male control rats. All the new information pinpoints CSE as a natural, sustainable and safe food ingredient containing fermentable fiber able to produce SCFAs with beneficial effects on gut microbiota.

Pharmacokinetic and pharmacodynamic properties of enrofloxacin in southern crested caracaras (Caracara plancus).

To determine the dosage of enrofloxacin in southern crested caracaras (Caracara plancus), plasma concentrations of enrofloxacin were measured by high-performance liquid chromatography after intravenous (IV) (5 mg/kg) and intramuscular (IM) (10 mg/kg) administration. This compound presented a relatively high volume of distribution (2.09 L/kg), a total body clearance of 0.24 L/kg x h, and a long permanence as shown by an elimination half-life of 7.81 hours after IV administration and a terminal half-life of 6.58 hours after IM administration. The areas under the concentration-time curves (AUC) were 21.92 and 34.38 microg x h/mL for IM and IV administration, respectively. Enrofloxacin was rapidly absorbed after IM administration with a time to reach maximum concentration of 0.72 hours and bioavailability of 78.76%. After IM administration, the peak drug concentration (C(max)) was 3.92 microg/mL. Values of minimum inhibitory concentration (MIC), C(max), and AUC have been used to predict the clinical efficacy of a drug in treating bacterial infections, with a C(max)/MIC value of 10 and an AUC/MIC ratio of 125-250 associated with optimal bactericidal effects. By using the study data and a MIC breakpoint of 0.25 microg/mL, values of C(max)/MIC were 13.74 and 15.94 and for AUC/MIC were 90.73 and 139.63, for the IV and IM routes respectively. For the treatment of infectious diseases caused by microorganisms with MIC < or = 0.25 microg/mL, the calculated optimal dosages were 7.5 and 9.5 mg/kg q24h by the IV and IM routes, respectively. For less susceptible bacteria, a dose increase should be evaluated. To treat caracara by the IV route against microorganisms with MIC < or = 0.25 microg/mL, the dose should be higher than the 5 mg/kg used in our study, but possible side effects derived from an increase in the IV dose and efficacy in sick birds should be assessed.

Marbofloxacin disposition after intravenous administration of a single dose in wild mallard ducks (Anas platyrhynchos).

Marbofloxacin, a fluoroquinolone developed specifically for veterinary use, has demonstrated considerable pharmokinetic variation among avian species. The goal of this study was to determine the disposition kinetics of marbofloxacin in mallard ducks (Anas platyrhynchos) after a single intravenous injection. Six wild mallard ducks were used in the study. Marbofloxacin was injected at a dose of 2 mg/kg into the basilic vein, and blood was subsequently collected at regular intervals from each bird. Plasma marbofloxacin concentrations were determined by using high-performance liquid chromatography. The volume of distribution at steady state was 1.78 +/- 0.37 L/kg, and the total plasma clearance was 0.59 +/- 0.08 L/kg per hour. Marbofloxacin had a relatively short permanence, with a elimination half-life of 2.81 +/- 1.20 hours, a terminal half-life of 2.43 +/- 0.61 hours, and a mean residence time of 2.99 +/- 0.52 hour. The maximum observed concentration (Cmax) and area under the curve (AUC) were 1.34 +/- 0.27 microg/mL and 3.75 +/- 0.56 microg x h/mL, respectively. Values of minimum inhibitory concentration (MIC), Cmax, and AUC have been used to predict the clinical efficacy of a drug in treating bacterial infections, with a Cmax: MIC value of 10 and an AUC: MIC ratio of 125-250 associated with optimal bactericidal effects. By using the study data and MIC breakpoints of 0.125 microg/mL or 0.2 microg/mL, values derived for Cmax: MIC were 9.37 +/- 0.99 and 5.85 +/- 0.62, respectively, and for AUC: MIC were 29.99 +/- 4.51 and 18.74 +/- 2.82, respectively. By using MIC values of 0.125 and 0.2 microg/mL and a target AUC: MIC = 125, the calculated optimal daily marbofloxacin dosages for mallard ducks were 9.24 and 14.78 mg/kg, respectively. These results suggest that, primarily because of the high total plasma clearance observed, the marbofloxacin dose for treatment of bacterial diseases in mallard ducks should be increased after intravenous administration. Intravenous doses of 10-15 mg/kg should be assessed by studying their potential toxicity and efficacy in sick birds.

Pharmacokinetics of marbofloxacin after intravenous and intramuscular administration to ostriches.

The pharmacokinetics of marbofloxacin was investigated after intravenous (IV) and intramuscular (IM) administration, both at a dose rate of 5 mg/kg BW, in six clinically healthy domestic ostriches. Plasma concentrations of marbofloxacin was determined by a HPLC/UV method. The high volume of distribution (3.22+/-0.98 L/kg) suggests good tissue penetration. Marbofloxacin presented a high clearance value (2.19+/-0.27 L/kgh), explaining the low AUC values (2.32+/-0.30 microgh/mL and 2.25+/-0.70 microgh/mL, after IV and IM administration, respectively) and a short half life and mean residence time (t(1/2 beta)=1.47+/-0.31 h and 1.96+/-0.35 h; MRT=1.46+/-0.02 h and 2.11+/-0.30 h, IV and IM, respectively). The absorption of marbofloxacin after IM administration was rapid and complete (C(max)=1.13+/-0.29 microg/mL; T(max)=0.36+/-0.071 h; MAT=0.66+/-0.22 h and F (%)=95.03+/-16.89).