EFFERVESCENT FORMULATIONS OF FLORFENICOL FOR ADDITION IN DRINKING WATER SYSTEMS Field of the Invention: The present invention relates to an effervescent pharmaceutical composition of florfenicol (FFC), and antibiotics of related structure in the form of blend powder, granules or tablets. The composition is providing a rapidly solubilizing additive for addition to drinking water systems for the treatment of bacterial infections in animals. Background of Invention: Florfenicol is a broad spectrum antibiotic, structurally related to thiomphenicol and chloramphenicol, which has been developed as a veterinary treatment for use in animals, particularly cattle, swine, poultry, and fish. Florfenicol is indicated for the control of mortality due to E. coli airsacculitis in broiler chickens, aRd for treatment and control of swine respiratory diseases associated with Actinobacillus pleuropneumoniae, P. multocida, Mycoplasma, Salmonella cholera suis and Streptococcus suis Type il. Currently veterinary products containing florfenicol are available in the form of injectable (for treatment of cattle respiratory diseases) powder or granules (addition to feed in aquaculture) and as concentrate nonaqueous organic solution (for addition in swine and poultry drinking water systems). The effervescent product designed for addition to drinking water systems has significant appeal to the industry because of its ease of administration. One currently marketed product is Nuflor® Concentrate Solution (Schering-Plough). Nuflor® Concentrate Solution uses a high content of organic solvent to provide an immediate solubilization of florfenicol in water and can be used not only in the bulk water source, at the efficacious concentration of 400 mg/gal (-0.1 mg/mL), but also with an automated proportioner mixing tank system (mixing ratio of 1 oz. to 1 gallon) at a concentration of -13.5 mg/mL. There are, however, some drawbacl