Oxytetracycline state

Veterinary Potential or Fiorfenicol. The absolute ban on the use of chloramphenicol ia food producing animals ia the United States and Canada has accentuated the need for an effective broad spectmm antibiotic ia animal food medicine. Fiorfenicol and other antibiotics commonly used ia veterinary medicine have been evaluated in vitro against a variety of important veterinary and aquaculture pathogens. Some of these data ate shown in Tables 4 and 5, respectively. Fiorfenicol was broadly active having MICs lower than those of chloramphenicol in each of the genera tested (Table 4). Florfenicol was also superior to chloramphenicol, thiamphenicol, oxytetracycline [79-57-2] ampicillin [69-53-4] and oxolinic acid [14698-29-4] against the most commonly isolated bacterial pathogen of fish in Japan (Table 5) (37). 

Most polymyxin B sold for human use in the United States is in dermatological, otic, and ophthalmic preparations that usually contain one or more other spectmm extending antibacterials such as bacitracin, neomycin sulfate [1404-04-2], C23H4gNg023, linear gramicidin, oxytetracycline [79-57-2],... 

Under current regulations, chemicals allowed for use in various European countries (Table 3) are either fully Hcensed for aquacultural use (oxytetracycline, oxolinic acid) or can be prescribed by veterinarians if they are Hcensed for use on other food animals (14—16). In addition, previously unHcensed chemicals that are appHed to the water (topicals) may now be used under a grandfather clause if no one questions their safety. The question of whether a chemical is a medicine or a pesticide has also been addressed. Eor example, dichlorvos (Nuvan 500 EC) was initially designated as a pesticide in the United Kingdom, but was later categorized as a medicine. A similar product, trichlorfon (Masoten), was treated the same way in the United States. 

The triplet-state energy level of oxytetracycline, the excitation maximum (412 nm), lifetimes of Eu-OxTc (58 p.s) and Eu-OxTc-Cit (158 p.s), were determined. A 25-fold luminescence enhancement at 615 nm occurs upon addition of citrate within a short 5-min incubation time at neutral pH. It s accompanied by a threefold increase of the luminescence decay time. The optimal conditions for determination of OxTc are equal concentrations of Eu(III) and citrate (C = T lO mol-E ), pH 7.2. Eor determination of citrate, the optimal conditions concentrations of Eu(HI) and OxTc are 1 0,5 (Cg = MO Huol-E-i, = 5-10-HuohE-i) at pH 7.2. 

For assaying oxytetracycline content in injections, tablets, capsules, ointments, and oral suspensions, the United States Pharmacopoeia 28 [1] uses a liquid chromatography method described in the assay under oxytetracycline. For oxytetracycline and Nystatin capsules and for oral suspension, United States Pharmacopoeia 28 [1] uses a microbiological method listed under antibiotics-microbial assays <81>. 

United States Pharmacopoeia 28 [1] describes a microbiological method under antibiotics-microbial assays for the analysis of OTC and nystatin capsules, OTC and nystatin for oral suspension, OTC HC1 and hydrocortisone ointment, and OTC HC1 and polymyxin B sulfate ointment. The methods are relative rather than absolute, which are based on the determination of the level of oxytetracycline by a microbiological response to a series of standard oxytetracycline concentrations by a... 

Present Label Implicitly Applies to Harvested Pollen. For beekeepers who use oxytetracycline for medication, the present label (Table I) is explicit in defining the proper use and precautions that need to be followed when honey is to be harvested and marketed for human consumption. Presumably the label implicitly applies to pollen collected for human consumption as well. This does, however, pose an interesting question - if fresh pollens were collected in pollen traps placed at the hive entrance of medicated colonies before the 4 week restriction elapsed, as stated on the use label for collecting marketable honey, would the oxytetracycline be transferred by the honey bee to the pollen. To answer the question field colonies were medicated by feeding freshly prepared solutions of medicated sugar syrup for several weeks at recommended and twice recommended levels. Immediately at the end of medication, and every 3 to 4 days thereafter, pollen traps were sampled and emptied to trap samples of pollen freshly collected by the foraging bees. 

In this symposium paper we have attempted to provide a synopsis of some of the research that has been performed by industry and government and have emphasized some of our own published research and included new findings concerning marketable pollen, that not only supports but may help to extend the label recommendations for proper use of oxytetracycline in bee colonies. These research efforts and the work of state apiary inspectors help combat the spread of bee diseases in economically important bee colonies while helping to prevent contamination of marketable honey and pollen. 

The effect on growth is highly persistent, and has continued for periods of up to 30 years or more in the same animal colonies, such as at Washington State University, the American Cyanamid Company (Table 3) and the University of Wisconsin. Growth promotion was still obtained with chicks in 1984 at Wisconsin by oxytetracycline and penicillin just as markedly as in 1951 ( ). 

Tetracyclines have been marketed since 1984, and, since discovery, some first-generation tetracyclines such as tetracycline, oxytetracycline, and chlorotetracychne have been extensively used in livestock and aquaculture, besides clinical use by humans. For human use, the second-generation tetracyclines doxycycline and minocycline have been prescribed to a great extent, and indeed prescription of the latter has steadily increased in the United States over the 2003-2005 period (Fig. 1.7). However, each of these tetracyclines is less than 0.5% of all the other 200 most prescribed dmgs. Tetracyclines are also prescribed to a good extent in several European countries (Fig. 1.6), with the exception of Italy and Denmark where per capita prescriptions are quite minimal, that is, <25 prescriptions per 1000 inhabitants (Molstad et ah, 2000). They are also widely used in animal husbandry where daily therapeutic doses of 40 mg tetracycline kg liveweight are typical (Kilhne et al., 2000). 

Analysis of the 1994 tissue residue data revealed that FSIS reported 2514 animals containing violative residues. FDA, in cooperation with participating states, conducted follow-up investigation on 1076 (45%) of the reported violations. The drugs most frequently identified as causing antibiotic residues included penicillin (21%), oxytetracycline (10%), sulfamethazine (10%), streptomycin (6%), tetracycline (5.2%), neomycin (4.1%), gentamicin (3.7%), and sulfadimeth-... 

In some cases, the same disease states exert no effect on drug pharmacokinetics as with amoxycillin and chloramphenicol in calves, and ampicillin and sulfamethazole in goats. Although feverish pigs show reduced elimination half-lives when oxytetracycline is given orally, there is no apparent effect after intravenous administration, which suggests an effect on gastrointestinal absorption (39). 

Diffuse reflectance spectroscopy (DRS), established by Kortum and co-workers in the 1950s,634 635 was employed by Lach and co-workers to detect the solid-state interactions between various drug substances such as oxytetracycline and various excipients such as... 

Demeclocycline, tetracycline, oxytetracycline, minocycline, and doxycycline are available in the United States for systemic use. Chlortetracycline and oxytetracycline are used in ophthalmic preparations. Methacycline is not available. Other derivatives are available in other countries. The more lipophilic drugs, minocycline and doxycycline, usually are the most active by weight, followed by tetracycline. Resistance of a bacterial strain to any one member of the class may result in cross-resistance to other tetracyclines. Bacterial strains with tetracycline minimum inhibitory concentrations (MICs) of < 4 pg/mL are considered susceptible... 

The absorption of tetracyclines from the G1 tract is non-uniform. Up to 30% of chlortetracycline is absorbed. The absorption for tetracycline, oxytetracycline, and demeclo-cycline ranges between 60 and 80%, whereas as much as 90 to 100% of doxycycline and minocycline is absorbed. The absorption of tetracyclines is impaired by divalent cations (calcium, magnesium, and ferrous iron), by aluminum, and by extremely alkaline pHs. Tetracyclines are distributed widely throughout the body fluid, cross the placental barrier, and can accumulate in growing bones. The concentrations of chlortetracycline in spinal fluid are only one fourth of those in plasma. Minocycline, a more lipid-soluble tetracycline, reaches a high concentration in tears and saliva and can eradicate the meningococcal carrier state. The tetracyclines are metabolized in the liver and excreted mainly by the bile and urine. The concentrations of tetracyclines in the bile are ten times higher than those in serum. 

On the average, 40% of the antibiotics sold in the United States, or more than 1.0 million kilograms, have been used as animal feed additives ( ). According to Aschbacher ( ), the following levels of antibiotic supplementation are recommended for growth promotion Bacitracin at 10-50 g/ton feed, Bambermycins at 1-2 mg/ton, Carbadox at 10-25 mg/ton, Chlorotetracycline at 10-50 mg/ton. Erythromycin at 4-70 g/ton, Lincomycin at 1-11 g/ton, Oxytetracycline at 5-50 g/ton. Penicillin at 2-50 g/ton, Tylosin at 4-100 g/ton and Virginiamycin at 10 g/ton. Higher levels have been recommended for prophylactic purposes. As medical and non-medical use of antibiotics increases, the risks associated with antibiotics in foods and feeds also increase. 

Terramycin is a brand name for the broad-spectrum antibiotic oxytetracycline. Although low levels of antibiotics such as Terramycin effectively extend the shelf life of food, the direct addition of antibiotics to foods is not permitted in the United States. After some initial studies and limited usage of antibiotics as food preservatives, the FDA withdrew their approval because of concern that repeated exposure of the consumer to low concentrations of antibiotics could lead to the development of antibiotic-resistant strains of bacteria. Furthermore, there was wariness lest antibiotics provide a substitute for good sanitary practices. 

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