What is Florfenicol?
Florfenicol is a fluorinated synthetic analog of thiamphenicol. It was successfully developed in late 1980s. It is a broad-spectrum antibacterial classified in chloramphenicol. Florfenicol was marketed first in Japan in 1990. In 1993, Florfenicol was approved by Norway for using in the treatment of dothienesis in trout. In 1995, it was approved by France, England, Austria, Mexico, and Spain for using in the treatment of bovine respiratory diseases. In Japan and Mexico, Florfenicol is approved as feed additive for pigs, preventing and treating swine bacteriosis. It has also been approved in China.

Pharmacology of Florfenicol
Due to its liposolubility, Florfenicol can diffuse into the cells of bacteria. It works on the 50s subunit of the 70s ribosome and restrain the extension of transpeptidase and thus the formation of peptide chain. The synthesis of protein is therefore prevented.
The antibacterial spectrum of Florfenicol is very broad. It is particularly effective against Grams positive and negative bacteria and mycoplasma. The bacteria that are sensitive to Florfenicol include hemophilus, Shigella dysenteriae, salmonella, colibacillus, pneumococcus, Bacillus influenzae, streptococcus, Staphylococcus aureus, chlamydia, Leptospira, and Rickett's organism, etc. in swine and cattle. Oral Florfenicol is fast to absorb. It distributes broadly in the body, with long half-life period, high blood concentration, and lasts long in blood.

Application of Florfenicol
Florfenicol is an antibacterial for animals. It is used for treatment of diseases in swine, chicken and fish caused by sensitive bacteria. It is especially effective in treatment of respiratory system infections and intestinal infection.
At first, Florfenicol was used in aquaculture. It is very effective in treating False nuclear Pasteurellosis and streptococcicosis of amberjack and the dothienesis natuarally attacking the Atlantic salmon. Moreover, Florfenicol shows better curative effect than other antibacterial against pasteurella infection of amberjack, Retardation of Edwardsiella tarda infection of eel, Vibrio infection of goldfish eel, and Vibrio salmonicida infection of salmon.
Besides, Florfenicol is also effective in treating bovine respiratory disease. According to Hass (1996), the cure rate of Florfenicol was 80%, while that of Amoxicillin was 50%. According to Madelent (1997), the cure rate of Florfenicol was 91%, in contrast to that the cure rate of Spiramycin was 41%.
According to Craene (1997), Florfenicol intravenous injected to cattle could enter the cerebrospinal fluid quite well. As a result, it is the first-choice cure for cattle meningitis.
Florfenicol is also used for the treatment of swine asthma, infectious pleuropneumonia, atrophic rhinitis, and swine plague. It is extremely effective for treating dyspnea, high body temperature, coughing, choking, appetite and weight loss of swine. It is also effective for treating piglet yellow-white dysentery, enteritis, bloody flux, edema disease and so on.
According to Ueda (1995), the cure rate of Florfenicol in treating swine Actinobacillus pleuropneumonia was as high as 100%. In contrast, the cure rate of Thiamphenicol was lower than 50%. 　
Florfenicol is a good treatment for poultry as well. It cures cholera, bacillary white diarrhea, diarrhoea, intractable diarrhea, yellow white green stool, liquid manure, alo laxata, intestinal mucosal punctate or diffuse hemorrhage, omphalitis, wrapped heart, and wrapped liver caused by Bacillus coli, salmonella, pasteurella multocida, etc., as well as the chronic respiratory disease, infectious coryza airbag opacity, coughing, the trachea slightly tone, and dyspnea caused by bacteria, mycoplasma and so on. In particular, Florfenicol is effective for treating duck infectious serositis, bacillus coli, pseudomonas aeruginosa and so on.
In the US, Florfenicol is currently indicated for the treatment of bovine respiratory disease (BRD) associated with Mannheimia (Pasteurella) haemolytica, Pasteurella multocida, and Haemophilus somnus, for treatment of bovine interdigital phlegmon, with the sympton of foot rot, acute interdigital necrobacillosis, infectious pododermatitis, associated with Fusobacterium necrophorum and Bacteroides melaninogenicus.
In the US, Florfenicol is also used in aquaculture, and is licensed for use in the US for the control of enteric septicemia in catfish.

Advantages of Florfenicol
Florfenicol is the structural homologues of Chloramphenicol. Its function mechanism and antibacterial spectrum is similar to Chloramphenicol and Thiamphenicol. However, taking Florfenicol will not result in drug-resistance as Chloramphenicol and Thiamphenicol will do (Varma,et al,1986;Lobell,et al,1994;Soback,et al,1995).
Moreover, because Chloramphenicol treatment comes with the side effect of Aplastic anemia, Chloramphenicol is forbidden in many countries for the treatment of animal diseases. However, Florfenicol does not have that side effect. As a result, Florfenicol will replace Chloramphenicol to be widely used in the prevention and cure of animal diseases.

Classfication of Florfenicol
(1) Florfenicol sodium succinate
(2) 90% Cold water soluble Florfenicol (chiral synthesis)
(3) 70% Water soluble Florfenicol