A Multi-center, Randomized, Double-blind, Double-dummy Clinical Study to Evaluate the Safety and Efficacy of Prulifloxacin Film-coated Tablet for the Treatment of Acute Exacerbations of Chronic Bronchitis With Levofloxacin Hydrochloride Tablet as Active Control

The purpose of this study is to use oral prulifloxacin to treat patient with Acute Exacerbations of Chronic Bronchitis and compare the effect with Levofloxacin.

Inclusion Criteria:

1. Patient is willing to participate in the study and gives the signature of informed consent;
2. In and out-patients (aged 18-70 years old), male or female;
3. Patient receives no effective antibacterial therapy or the therapy has no remarkable efficacy, or positive bacterial test result in the past 72 hours;
4. Diagnosed as mild to moderate acute exacerbation of chronic bronchitis patients (see <Severity Evaluation Criteria Table>)
5. Within 48 hours prior to the study, women of child-bearing age have a negative urine pregnancy test and is willing to use efficient measures of contraception to avoid pregnancy during the study.

Exclusion Criteria:

1. Patient hypersensitive to quinolones or with allergic constitution;
2. Patient with severe condition which need combination with other antibacterial agents;
3. Concurrent infections in other organs or system;
4. Patient with severe heart, liver or kidney disease, or Q-T prolongation of over 450 ms, serum AST or ALT more than twice as high as the upper limit of normal or Cr over the upper limit of normal;
5. With any of the following diseases: active tuberculosis, bronchiectasis, lung abscess, aspiration pneumonia, lung cancer, non-infectious interstitial lung disease, pulmonary edema, atelectasis, pulmonary embolism, pulmonary addicted acidic granulocyte infiltration and pulmonary vasculitis syndrome;
6. Patient with severe hematologic disease or central nervous system disease or convulsion history, with mental status unable to coordinate;
7. Patient with malignant tumor or other severe background disease;
8. Patient with severe immunodeficiency;
9. A history of tendon;
10. Known pregnancy or lactation;
11. Prulifloxacin contains lactose, therefore, patients with a rare genetic disease such as galactose intolerance, Lapp lactase deficiency or glucose - galactose malabsorption cannot be enrolled;
12. Participation in other clinical trials within 3 months before screening or currently on any investigational therapy.