• YAKHAK HOEJI
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• v.40 no.3
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• pp.343-346
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• 1996

The influence of LB20304a, a new fluoroquinolone antibiotic agent, on microflora of caecum in mice was compared with those of ciprofloxacin and piperacillin after administration of drugs for 5 days. Selective medium (CCFMA) was used for the isolation of Clostridium difficile from the specimens of mouse caecum. The emergence of C. difficile in mouse caecum induced by LB20304a was lower than that by ciprofloxacin or piperacillin at day 1 and day 7 after completing administration of drugs.

• Archives of Pharmacal Research
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• v.19 no.5
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• pp.359-367
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• 1996

The pharmacokinetics of LB20304 was investigated following intravenous (IV) and oral administration to rats and dogs. Additionally, in vitro metabolism and serum protein binding studies were also conducted. The total body clearance, apparent volume of distribution, terminal half-life, and extent of bioavailability were 21.8 ml/min/kg, 2265 ml/kg, 93.6 min, and 30.8% for rats; and 7.95 ml/min/kg, 4144 ml/kg, 363 min, and 81.1% for dogs, respectively. LB20304 was stable in the liver microsome containing NADPH generating system and its serum protein binding was 58.5-65.8% for rats, 19.1-29.6% for dogs, and 56.9-59.6% for humans. Its tissue concentration levels in lever, stomach, small intestine, and kidney were 9.5 to 26.1 times greater than plasma level, but the concentration in testis was quite low and that in brain was negligible in rats. The 48 hr urinary recovery of the dose was 44% for IV dosing and 14% for oral dosing, shereas the 48 hr biliary recovery of the dose was 6.4% for IV dosing and 4.5% for oral dosing in rats. In summary, the pharmacokinetic properties of LB20304 were characterized by its good oral absorption, long plasma half-life, and good tissue distribution.

• Proceedings of the PSK Conference
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• 2000.04a
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• pp.64-65
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• 2000

• Archives of Pharmacal Research
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• v.19 no.6
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• pp.554-558
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• 1996

High-performance liquid chromatographic method was developed for the determination or LB 20304 (compound 1) in the plasma of rats and dogs. The analyte was deproteinized with 1 volume of methanol and 1/2 volume of 10% zinc sulfate, and the supernatant was injected onto a reversed-phase HPLC column. The mobile phase was a mixture of 24 parts of acetonitrile and 76 parts of 0.1% trifluoroacetic acid. The flow rate was 1 ml/min, and the effluent was monitored by fluorescence detector at an excitation wavelength of 337 nm and an emission wavelength of 460 nm. The retention time of compound 1 was 6.3 min. The assay of compound 1 was linear over the concentration range of 0.2-100.mu.g/ml in the plasma of rats and dogs. The lower limit of quantification was 0.2.mu.g/ml using 100.mu.l of plasma with a 97-99% accuracy and a 12-14% precision. In the 0.5, 5, and 50.mu.g/ml quality control samples, the intra- and inter-day accuracy were 88-95% and 88-97%, whereas intra- and interday precision were 0.5-6.6% and 0.2-9.3%, respectively, in the plasma of rats and dogs. The recoveries were 68-71% independent of concentration and species in the plasma. No interferences from endogenous substances were observed. Taken together, the above HPLC assay method by deproteinization and fluorescence detection was suitable for the determination of compound 1 in the preclinical pharmacokinetics.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.04a
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• pp.6-11
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• 1997

• Knowledge Management Research
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• v.2 no.1
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• pp.109-132
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• 2001

The purpose of this article is to develop a dynamic model of organizational capabilities and knowledge creation, and at the same time identify the organizational capability factors for effective knowledge creation, by empirically analyzing the history of new Quinolone antibacterial drug compound (LB20304a) discovery process at LG, as a case in point. Major findings of this study are as follows. First, in a science-based area such as drug development, the core of successful knowledge creation lies in creative combination of different bodies of scientific explicit knowledge. Second, the greater the difficulty of learning external knowledge, the more tacit knowledge is needed for the recipient firm to effectively exploit that knowledge. Third, in science-based sector such as pharmaceutical industry, the key for successful knowledge creation lies in the capability of recruiting and retaining star scientists. Finally, for effective knowledge creation, a firm must keep its balance among three dimensions of organizational capabilities: local, process, architectural capabilities.

• Tuberculosis and Respiratory Diseases
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• v.55 no.1
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• pp.69-87
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• 2003

Background : LB20304(gemifloxacin) is a new fluoroquinolone antibacterial agent with excellent activity against both Gram-negative and Gram-positive organisms. In vitro studies using clinical isolates have shown gemifloxacin to be highly active against penicillin-resistant strains of S. pneumoniae and in contrast to other reference quinolones, gemifloxacin retained good activity against clinical isolates of S. pneumoniae that were resistant to other members of the quinolone class. Therefore, gemifloxacin is thought to be effective in treating acute bacterial exacerbation of chronic bronchitis(AECB). The objective of this study was to evaluate the efficacy and safety of oral gemifloxacin at doses of 160mg or 320mg once daily for 7 days for the treatment of AECB in Korean adult population. Methods : This was a randomized, multicenter, double-blind, parallel group Phase II study to assess the clinical and antibacterial efficacy and safety of oral gemifloxacin for the treatment of AECB. Treatment Group A (67 patients) took oral gemifloxacin 160mg once daily for seven days and treatment Group B (70 patients) took oral gemifloxacin 320mg once daily for seven days. Results : The demographic profiles of the two treatment groups were similar. The clinical response at follow-up was 84.2% in the gemifloxacin 160-mg group, and 88.7% in the gemifloxacin-320 mg group, showing no statistically significant difference between two treatment groups(p=0.49). The clinical response at the end of therapy was 96.5% in the 160-mg group, and 96.4% in the 320-mg group. The bacteriological response at the end of therapy and follow-up were 81.8% and 78.9%, respectively, in the 160-mg group, and 86.4% and 84.2%, respectively, in the 320-mg group, showing no statistically significant difference between two treatment groups(p=0.68 and 0.68, respectively). S. pneumoniae(12 isolates) and H. influenzae(10 isolates) were the most prevalent pathogens. The MICs were lower for gemifloxacin than other quinolones against these key pathogens, and for S. pneumoniae, the MICs for gemifloxacin were considerably lower(${\leq}0.03$ ug/mL) than those for other quinolones, beta-lactams and macrolides. In the period on-therapy plus 30 days post-therapy, a total of 18 patients(26.9%) in the gemifloxacin 160mg group and 22 patients(31.4%) in the 320mg group reported at least one adverse event(AE). The most frequently reported AE was abdominal pain(3/67 patients, 4.5%) in the gemifloxacin 160mg group and increased level of hepatic enzyme(5/70 patients, 7.1%) in the 320mg group. The overall AE profiles for the two treatment groups were similar. Two out of 67 patients(3.0%) in the gemifloxacin 160mg group and 1/70 patients(1.4%) in the 320mg group reported at least one serious AE, however, none of which was considered by the investigator to be of suspected or probable relationship to study medication. Conclusion : The results of this study showed that gemifloxacin at doses of 160mg or 320mg once daily for 7 days in the treatment of acute exacerbations of chronic bronchitis(AECB) in adult Koreans was a very effective and safe treatment both clinically and bacteriologically.