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Pharmacokinetic profile of sulphamonomethoxine-trimethoprim in horses after intravenous, intramuscular and oral administration.
No full textThe pharmacokinetic profile of a sulphamonomethoxine-trimethoprim (SMM-TMP) combination was investigated in five horses. The combination was administered intravenously, intramuscularly and orally at a constant dose of 20 mg SMM plus 4 mg TMP kg-1 bodyweight. Following intravenous administration both drugs dispersed rapidly with distribution half-lives of about 12 minutes for SMM and about 18 minutes for TMP. Elimination half-lives for intravenous, intramuscular and oral administration were closely similar, indicating that elimination was independent of administration route. Bioavailability of the drugs in aqueous solution was good: about 72 per cent and 84 per cent for SMM and about 84 per cent and 98 per cent for TMP following intramuscular and oral administration, respectively. It is concluded that SMM-TMP administered orally once a day at 20 mg and 4 mg kg-1 bodyweight, respectively, maintains therapeutic concentrations, whereas twice daily intramuscular administration would be more effective for treating systemic infections in the horse than the once a day regimen usually adopted in veterinary practic
Pharmacokinetics of sodium amoxicillin in horses.
No full textThe pharmacokinetics of sodium amoxicillin were investigated after intravenous and intramuscular administration of a single dose of 15 mg kg-1 body-weight to five horses. A rapid distribution phase was noted after intravenous administration (t1/2 alpha about 20 minutes). The t1/2 beta values obtained after the intravenous and the intramuscular administration were significantly different (P less than 0.05). The bioavailability obtained was about 67 per cent. Plasma protein binding, evaluated in vitro, showed that the percentage of bound fraction was 37 to 38 per cent. It was concluded that sodium amoxicillin administration at 15 mg kg-1 four times a day should be effective in the treatment of several systemic infections in the hors
Comparative pharmacokinetics of ampicillin-sulbactam combination in calves and sheep.
No full textThe pharmacokinetics of ampicillin and sulbactam administered in combination were studied in calves and sheep. The animals were administered an aqueous solution of ampicillin/sulbactam (2:1, w/w) intravenously and intramuscularly at doses of 13.2 and 6.6 mg.kg-1, respectively. A microbiological method was used to detect ampicillin, and HPLC was used to detect sulbactam in serum. Following intravenous (i.v.) administration, the distribution phases were rapid and similar (about 15 min) for both drugs in both species, whereas sulbactam in calves and ampicillin in sheep showed a faster elimination rate. After intramuscular (i.m.) administration both drugs showed peak concentrations higher in calves than in sheep; the peak time of sulbactam was shorter in calves than in sheep. No other significant differences in the pharmacokinetics of the combination were observed between the species after i.m. injection. The mean residence and absorption times, calculated by non-compartmental analysis, for both calves and sheep suggested that the differences in ampicillin and sulbactam pharmacokinetics could be attributable to the different molecular structure
Pharmacokinetic of sodium cefoperazone in calves.
No full textNa-CPZ was administered to ten calves i.v. and i.m. at the dosages of 15 and 30 mg/Kg b.w. in order to study its pharmacokinetic parameters. Plasma protein binding was evaluated in vitro by the ultracentrifugation technique. Short half-lives were obtained after i.v. (53.61 min) and i.m. (47.71 min) administration at the dosage of 15 mg/kg b.w., similar values were obtained after i.v. (55.19 min) and i.m. (64.21 min) administration of 30 mg/kg b.w. The mean value of bioavailability (F) following the injection of both dosages was about 45%. Plasma protein binding at therapeutical concentrations was evaluated about 44%. The Authors conclude that a daily i.m. administration of 30 mg/Kg b.w. of Na-CPZ produces serum therapeutical levels for about 8 hours against the most sensitive microorganisms and 5 hours against the less sensitive ones
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Comparative pharmacokinetics of amikacin sulphate in calves and sheep.
No full textThe pharmacokinetics of amikacin sulphate were investigated in calves and sheep. Five animals of each species were given 7.5 mg kg-1 intravenously and intramuscularly. After intravenous administration the pharmacokinetic parameters significantly different (P less than 0.01) between calves (first value) and sheep (second value), were: the initial concentration (87.05, 146.6 micrograms ml-1), the apparent distribution volume (350, 200 ml kg-1), the area under curve (5512, 11,018 min micrograms ml-1) and the clearance (1.5, 0.7 ml min-1 kg-1). After dosing intramuscularly the peak concentration (23.5, 34.36 micrograms ml-1), the peak time (45, 75 min) and the area under curve (5458, 9191 min micrograms ml-1) were significantly different (P less than 0.01). No significant differences were observed in the terminal halflife values, suggesting that elimination rate was independent of both route of administration and animal species. The drug in aqueous solution showed a good bioavailability in both animal species (about 0.87 in sheep and greater than 0.99 in calves) despite the greater serum concentrations always attained in shee
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