The present study was planned to evaluate the bioequivalence of two commercial formulations of enrofloxacin, which have been marketed as 10% injectable solution after intramuscular administration at a single dose of 2.5 mg/kg body weight to 12 clinically healthy goats The study was carried out on the basis of crossover design. The two formulations were: Baytril as a reference product and Spectrama Vet as a test product. The plasma concentrations of enrofloxacin were measured by high performance liquid chromatography (HPLC) with UV detector. The pharmacokinetics of that data was performed using non-compartmental analysis. The maximum plasma concentration (Cmax), time to reach peak concentration (Tmax), area under concentration-time curve (AUC), elimination half-life (t0.5el) were 1.14 and 1.05 μg/mL, 0.79 and 0.83 h, 5.70 and 5.79 μg.h/mL, 5.19 and 5.39 h for Baytril and Spectrama Vet, respectively. The 90% confidence interval for the mean ratio of Tmax, Cmax and AUC were 94.72~116.2, 87.88~97.16 and 86.44~118.72%, respectively. These values falls within the European Medicines Agency bioequivalence acceptance range of 80~125% for both Tmax and AUC and between 75~133% for Cmax. In conclusion, Spectrama-Vet is bioequivalent to Baytril and both products can be used as interchangeable drug in veterinary medicine practice.

We have studied pharmacokinetics of a new anti-human immunodeficiency virus (HIV) agent VP-0501 and its amino acid prodrug VP-0501AL which is designed to improve oral bioavailability. After oral administration at 100 mg/kg dose in rats (n=4), VP-0501 was not detectable in plasma (less than 50 ng/ml), while after the administration of VP-0501AL, VP-0501 was quantitatively detected, at least for 8 hrs, with Cmax of ca. 2.5 μg/ml and AUC of 8 hr*μg/ml.

Amikacin is a semisynthetic derivative of kanamycin and primarily active against aerobic Gram-negative-pathogens with limited activity against Gram-positive bacteria. Meager study was reported on pharmacokinetic data on multi-days administration of amikacin. Hence, pharmacokinetics study was done in five clinically healthy goats (n = 5), after intravenous bolus injection of amikacin sulfate at the dose rate of 10 mg/kg body weight daily for three consecutive days. The amikacin concentrations in plasma and pharmacokinetics-parameters were analyzed by using microbiological assay technique and non-compartmental open-model, respectively. The mean peak plasma concentrations (Mean ± SD) of amikacin at time zero (Cp∨0) was 114.19 ± 20.78 and 128.67 ± 14.37 ㎍/mL, on day 1st and 3rd, respectively. The mean elimination half-life (t∧1/2ke) was 1.00 ± 0.28 h on day 1st and 1.22 ± 0.29 h on day 3rd. Mean of area under concentration-time curve (AUC∧0→∞) was 158.26 ± 60.10 and 159.70 ± 22.74 ㎍.h/mL, on day 1st and 3rd respectively. The total body clearance (Cl∧B) and volume of distribution at steady state (Vdss) on day 1st and 3rd were Cl∧B = 0.07 ± 0.02 and 0.06 ± 0.01 L/h.kg and Vdss = 0.10 ± 0.03 and 0.11 ± 0.05 L/kg, respectively. No-significant difference was noted in both drug-plasma concentration and pharmacokinetics-parameters, respectively. Amikacin concentration in plasma was found higher up-to 4 h and 6 h onward on down-ward trends favour to reduce toxicity. Which also support the pharmacokinetic-pharmacodynamic way of dosing of aminoglycosides and hence, amikacin may be administered 10 mg/kg intravenously daily to treat principally Gram-negative pathogens and limitedly Gram-positive-pathogens.

Combination therapy of antibiotics is leading to improved efficacy or safety profiles with decrease emergence of bacterial resistance. Because of this benefit, many of antibacterial combinations have been used in veterinary practice for the past few decades. The purpose of this study was to examine the in vitro activity of an amoxicillin alone and in combination with other antibiotics against pathogenic bacteria of fish origin. Based on the fractional inhibitory concentration (FIC) index (FIC less-than or equal to 0.5), a synergistic interaction was shown in combination of florfenicol with amoxicillin or cefuroxime. The combination of florfenicol and amoxillin showed higher antibacterial activity than that of florfenicol and cefuroxime. Ratio of amoxicillin and florfenicol in combination was 1 : 1, which showed the antibacterial activity against bacterial isolates of fish as compared with other ratios. A synergetic effect of the combination (amoxicillin and florfenicol) was further confirmed in the time-kill curve study. The study showed a better in vitro antibacterial activity of a 1 : 1 combination of amoxicillin and florfenicol than the individual antibacterial against bacterial isolates of fish. In conclusion, the combination of florfenicol and amoxicillin may serve as a potential antibacterial therapy in fishes infected pathogenic bacteria.