This paper reports an open label study of the pharmacokinetics of ofloxacin conducted on 12 Vietnamese healthy volunteers (4 females, 8 males). Oflaxacin was adminitered as an oral tablet presentation. The mean peak concentration was 2.270.53 mg.liter-1, occuring at 1.300.31h after dosing. The AUCo-24was 16.532.02mg.h.liter-1, the half-time was 5.040.44h and the volume of distribution was 1.120.18 liter.kg-1. Results collected from this study were similar to those of previous studies.
Pharmacokinetics ; Ofloxacin ; tablets\

Ofloxacin was administered to six male goats intravenously (5 mg/kg) to determine its kinetic behavior, tissue residue, in vitro plasma protein binding and to compute a rational dosage regimen. The concentration of ofloxacin in plasma and tissue samples collected at prescheduled time were estimated by using HPLC. The pharmacokinetic parameters were determined by non-compartmental model and plasma protein binding was estimated by equilibrium dialysis technique. The therapeutic concentration (> or = 0.5 microgram/ml) was maintained up to 36 h and the initial concentration at 2.5min (14.76 +/- 0.47 microgram/ml) declined to 0.05 +/- 0.03 microgram/ml at 96 h with a secondary peak (0.64 +/- 0.15 microgram/ml) at 24 h. The mean AUC, AUMC, t1/2, MRT, Cl and Vd were calculated to be 58.94 +/- 19.43 microgram h/ml, 1539.57 +/- 724.69 microgram h2/ml, 15.58 +/- 1.87 h, 22.46 +/- 2.71 h, 135.60 +/- 31.12 ml/h/kg and 2.85 +/- 0.74 L/kg respectively. Significantly high concentration of drug was detected in different tissues after 24 h of intravenous dosing of 5mg/kg, at 24 h interval for 5 days. The in vitro plasma protein binding of ofloxacin was found to be 15.28 +/- 0.94%. Based on these kinetic parameters, a loading dose of 5mg/kg followed by the maintenance dose of 3mg/kg at 24 h dosing interval by intravenous route is recommended.
Animals ; Anti-Infective Agents/*pharmacokinetics ; Blood Proteins/*metabolism ; Chromatography, High Pressure Liquid/veterinary ; Goats/*metabolism ; Male ; Ofloxacin/*pharmacokinetics ; Protein Binding ; Tissue Distribution

The present study aimed to investigate the pharmacokinetic variation of ofloxacin based on gender-related difference in the expression of multidrug resistance-associated protein (Abcc2/Mrp2) in rat kidney. The concentrations of ofloxacin in rat plasma and urine were determined after tail vein administration (30 mg x kg(-1)) by high-performance liquid chromatography (HPLC) method. Expression of Mrp2 in kidney of male and female rats was qualitatively and quantitatively detected by immunohistochemistry and flow cytometry, separately. The results showed that AUC value of ofloxacin was lower in male rats than that in female rats and the total amount of ofloxacin excreted in the urine was higher in male rats than that in female rats. And the expression of Mrp2 in male rat kidney was higher than that in female rats. All results suggested that gender-related differences in pharmacokinetics of ofloxacin may be attributed to the differences in the expression of Mrp2 in kidney of male and female rats.
ATP-Binding Cassette Transporters ; metabolism ; Animals ; Anti-Bacterial Agents ; blood ; pharmacokinetics ; urine ; Area Under Curve ; Female ; Kidney ; metabolism ; Male ; Ofloxacin ; blood ; pharmacokinetics ; urine ; Rats ; Rats, Wistar ; Sex Characteristics

AIMTo establish a method for determineation of the concentration of ofloxacin in human fallopian tube, uterus and serum.

METHODSThe separation was performed on a Spherisob C18 column (Hypersil, 250 mm x 4.6 mm ID, 5 microns) with a mobile phase of acetonitrile-0.01 moL.L-1 potassium dihydrogen phosphate-0.5 mol.L-1 tetrabutylammonium bromide (9:91:4, pH 2.5). The flow rate was 1.0 mL.min-1 and detection was at 294 nm. The samples were homogenated or ground to powder after freezing with liquid nitrogen. 1% triton-100 and certain volume of ethylacetate-isopropanol (10:1) were added, shaken and centrifuged. Then the entire organic layer was transferred to a tube and vacuum dried. The residue was reconstituted in the mobile phase for HPLC.

RESULTSThere was a linear relationship between the peak area ratio and the ofloxacin concentration over the range of 0.2-8.0 micrograms.mL-1. The limits of detection was 40 ng.mL-1. Using this method to determine the ofloxacin concentrations in relevant organs as well as in the plasma of patients of the Department of Gynecology, and achieved satisfactary results.

CONCLUSIONThe method can be applied to assay the ofloxacin concentration in human tissues. Ofloxacin was well distributed in woman fallopian tube, uterus and serum after single oral administration.

Adolescent ; Adult ; Anti-Infective Agents ; analysis ; pharmacokinetics ; Chromatography, High Pressure Liquid ; Fallopian Tubes ; metabolism ; Female ; Humans ; Ofloxacin ; analysis ; blood ; pharmacokinetics ; Tissue Distribution ; Uterus ; metabolism

The disposition kinetics of levofloxacin was investigated in six male crossbred calves following single intravenous administration, at a dose of 4 mg/kg body weight, into the jugular vein subsequent to a single intramuscular injection of paracetamol (50 mg/kg). At 1 min after the injection of levofloxacin, the concentration of levofloxacin in plasma was 17.2 +/- 0.36 microgram/ml, which rapidly declined to 6.39 +/- 0.16 microgram/ml at 10 min. The drug level above the MIC90 in plasma, was detected for up to 10 h. Levofloxacin was rapidly distributed from blood to the tissue compartment as evidenced by the high values of the distribution coefficient, alpha (17.3 +/- 1.65 /h) and the ratio of K12/K21 (1.83 +/- 0.12). The values of AUC and Vdarea were 12.7 +/- 0.12 microgram.h/ml and 0.63 +/- 0.01 l/kg. The high ratio of the AUC/MIC (126.9 +/- 1.18) obtained in this study indicated the excellent antibacterial activity of levofloxacin in calves. The elimination half-life, MRT and total body clearance were 1.38 +/- 0.01 h, 1.88 +/- 0.01 h and 0.32 +/- 0.003 l/kg/h, respectively. Based on the pharmacokinetic parameters, an appropriate intravenous dosage regimen for levofloxacin would be 5 mg/kg repeated at 24 h intervals when prescribed with paracetamol in calves.
Acetaminophen/administration & dosage/*pharmacokinetics ; Animals ; Anti-Bacterial Agents/administration & dosage/blood/*pharmacokinetics ; Area Under Curve ; Cattle/*metabolism ; Drug Therapy, Combination ; Half-Life ; Hybridization, Genetic ; Injections, Intravenous/veterinary ; Male ; Ofloxacin/administration & dosage/blood/*pharmacokinetics ; Time Factors

BACKGROUND: There are few studies that have reported on the pharmacokinetic(PK) disposition of fluoroquinolones in patients with multi-drug resistant tuberculosis(MDR-Tb), even though fluoroquinolones are frequentl y co-prescribed to those patients. In this study, the PK disposition of ofloxacin, a fluoroquinolone, was evaluated in patients with MDR-Tb. METHODS: Twenty patients with MDR-Tb were given 2nd line Tb drugs including ofloxacin (300mg twice a day), prothionamide, cycloserine, para-aminosalicylic acid, kanamycin, and streptomycin. The patients were grouped according to their body mass index(BMI) as an index of emaciation (group A: 18.5ofloxacin concentrations were determined using HPLC (High Performance Liquid Chromatography). RESULTS: The AUC of ofloxacin in group B was greater than that in group A (31.4+/-8.9micro gram/ml.h vs. 24.1+/-6.2micro gram/ml.h)(Check the symbols),(p<0.05). The total clearance(CI/F) of ofloxacin was 0.16+/-0.03 l/h/kg in group A, and 0.14+/-0.03 l/h/kg in group B. The half-lives of ofloxacin in two groups were similar (group A: 5.3+/-0.8 hours, group B: 5.7+/-0.9 hours). In addition, the other PK parameters in two groups were also similar. CONCLUSIONS: The pharmacokinetics of ofloxacin in patients with MDR-Tb appears to be comparable with those of normal subjects, and the extent of emaciation appears to have an influence on the pharmacokinetics of ofloxacin in chronic debilitated MDR-Tb patients.
Aminosalicylic Acid ; Area Under Curve ; Chromatography, High Pressure Liquid ; Cycloserine ; Emaciation ; Fluoroquinolones ; Humans ; Kanamycin ; Ofloxacin* ; Pharmacokinetics* ; Prothionamide ; Streptomycin ; Tuberculosis, Multidrug-Resistant*

The pharmacokinetics and urinary excretion following single intramuscular administration of levofloxacin at a dose of 4 mg/kg was investigated in seven male cross bred calves. Appreciable plasma concentration of levofloxacin (0.38 +/- 0.06 microgram/ml) was detected at 1 min after injection and the peak plasma level of 3.07 +/- 0.08 microgram/ml was observed at 1 h. The drug level above MIC(90) in plasma was detected up to 12 h after administration. Rapid absorption of the drug was also evident by the high value of the absorption rate constant (2.14 +/- 0.24 /h). The overall systemic bioavailability of levofloxacin, after intramuscular administration, was 56.6 +/- 12.4%. The high value of AUC (7.66 +/- 0.72 mg.h/ml) reflected the vast area of body covered by drug concentration. Extensive distribution of the drug into various body fluids and tissues was noted by the high value of Vd(area) (1.02 +/- 0.05 l/kg). The high ratio of AUC/MIC (76.6 +/- 7.25) obtained in this study indicated excellent clinical and bacteriological efficacy of levofloxacin in calves. The elimination half-life and MRT were 3.67 +/- 0.4 h and 5.57 +/- 0.51 h, respectively. The total body clearance (Cl(B)) was 204.9 +/- 22.6 ml/kg/h. On the basis of the pharmacokinetic parameters, a suitable intramuscular dosage regimen for levofloxacin in calves would be 1.5 mg/kg repeated at 12 h intervals.
Animals ; Anti-Bacterial Agents/administration & dosage/blood/*pharmacokinetics/urine ; Area Under Curve ; Biological Availability ; Cattle/*metabolism/urine ; Half-Life ; Injections, Intramuscular/veterinary ; Male ; Ofloxacin/administration & dosage/blood/*pharmacokinetics/urine

BACKGROUNDA new fluroquinolone antibacterial agent, antofloxacin hydrochloride, developed in China, is an 8-NH(2) derivant of levofloxacin. The purpose of the study was to evaluate the pharmacokinetic characteristics of single and multiple oral doses of antofloxacin hydrochloride in Chinese healthy male volunteers.

METHODSAn open-label, non-randomized, single and multiple dose clinical trial was conducted. In single dose study, 12 subjects took 200 mg antofloxacin hydrochloride. In multiple dose study, 12 subjects took antofloxacin hydrochloride 400 mg once on day 1 and 200 mg once daily from day 2 to day 7. HPLC was used to assay the serum and urinary concentrations of antofloxacin.

RESULTSIn single dose study, the maximum concentration of drug in serum (C(max)), the time to reach C(max) (T(max)), and the area under the serum concentration-time curve (AUC (0-∞)) of antofloxacin were (1.89 ± 0.65) mg/L, (1.29 ± 0.26) hours, and (25.24 ± 7.26) mg×h(-1)×L(-1), respectively. Accumulating elimination rate of antoflocaxin from urine within 120 hours was 39.1%. In multiple dose study, blood concentration of antofloxiacin achieved stable state on day 2 after dosing. The minimum concentration drug in serum (C(min)), AUCss, mean concentration of drug in serum (C(av)), and degree of fluctuation (DF) were (0.73 ± 0.18) mg/L, (47.59 ± 7.85) mg×h(-1)×L(-1), (1.98 ± 0.33) mg/L, and 1.74 ± 0.60, respectively. On day 7 after dosing, T(max), C(max), and AUC (0-∞) was (1.14 ± 0.50) hours, (2.52 ± 0.38) mg/L, and (48.77 ± 8.44) mg×h(-1)×L(-1), respectively. Accumulating elimination rate of antofloxaxin from urine within 120 hours after the last dosing was 60.06%.

CONCLUSIONSThe regimen of 400 mg loading dose given on the first treatment day and then 200 mg dose once daily results in satisfactory serum drug concentration.

Administration, Oral ; Adolescent ; Adult ; Anti-Bacterial Agents ; administration & dosage ; blood ; pharmacokinetics ; urine ; Chromatography, High Pressure Liquid ; Humans ; Levofloxacin ; Male ; Ofloxacin ; administration & dosage ; analogs & derivatives ; blood ; pharmacokinetics ; urine ; Young Adult