Oxytetracycline Foods: Milk

Concomitant use of tetracycline with antacids containing aluminum, calcium, or magnesium decreases absorption of oxytetracycline (because of chelation) concomitant use with food, milk or other dairy products, oral iron products, or sodium bicarbonate also impairs oral absorption. 

A number of methods have been described for determination of tetracycline (chlortetracycline, tetracycline, and oxytetracycline) residues in tissues of food-producing animals (53-62), fish (63), eggs (64), and honey (65,66). Most of these methods use reversed-phase HPLC for determination. However, one uses TLC with UV densitometry ( ) and one uses GLC ( ), and one uses a direct mass spectrometric method CAD MIKE spectrometry (collisionally activated decomposition mass-analyzed ion kinetic spectrometry) for oxytetracycline in milk and meat (62). Several use solid-phase extraction in the cleanup procedure using XAD-2 resin (56,58) or Cj g cartridges... 

Oxytetracycline is licensed to be taken four times a day, but can be taken twice a day for the treatment of acne (two 250 mg tablets twice a day). These oxytetracycline tablets should be taken 1 hour before or 2 hours after meals, followed by a glass of water. They should NOT be taken at the same time as milk, food or antacids, as they can make the medicine less effective. Tablets should be swallowed when either sitting or standing and they should not be taken immediately before going to bed. The complete course of prescribed tablets should be completed. 

Food safety concerns were also addressed via IPC. Many veterinary drugs were controlled in a broad range of food matrices. For example, a specific IPC strategy was developed for routine determination of the marker residues of oxytetracycline in edible animal tissues [36]. Dihydrostreptomycin is an aminoglycoside antibiotic used in veterinary medicine in combination with benzylpenicillin to treat bacterial infections in cattle, pigs and sheep its IPC quantitative determination in bovine tissues and milk was developed and optimized [37,38]. 

Eritz J, Zuo Y, Simultaneous determination of tetracycline, oxytetracycline, and 4-epitetracycline in milk by high performance liquid chromatography. Food Chem. 2007 107 1297-1301. 

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