NewFlockOnTheBlock
Songster
Asking "How long is a newly opened bottle of oxytetracycline good for" might sound like a silly question ("Look at the expiration date on the package, duh") but hear me out: it's more complicated than you might think. The package says the expiration date is November 17, 2020. However, it ALSO says, "use within 28 days of first vial puncture," and "stopper may be punctured a maximum of 40 times."
I understand that the expiration date refers to how long the medication may be stored unopened, and then once it's opened you're supposed to toss it after 28 days and only stick a needle through the rubber top up to 40 times. However, what does all this REALLY mean and is there a way to extend oxytetracycline's shelf life after that first vial puncture? For example, if you cover the rubber seal tightly with a piece of aluminum foil or plastic wrap after each use, will it help? Also, the package says to store this medication at room temperature, but will storing it in the fridge help it stay fresh longer?
Tetracycline is one of those antibiotics that actually becomes toxic to the liver if it goes bad, so I assume oxytetracycline behaves the same way (couldn't find any info specific to oxytetracycline online). I obviously don't want to put our chicken's health at risk but I also don't want to waste medication or money. Oxytetracycline is pricey at our feed store, about $35 per bottle, and we will be using only a small portion of the 100 mL bottle over the next 2-3 weeks and will likely need to repeat treatment in a few months. (We are treating just one chicken for a recurrent infection.)
I understand that the expiration date refers to how long the medication may be stored unopened, and then once it's opened you're supposed to toss it after 28 days and only stick a needle through the rubber top up to 40 times. However, what does all this REALLY mean and is there a way to extend oxytetracycline's shelf life after that first vial puncture? For example, if you cover the rubber seal tightly with a piece of aluminum foil or plastic wrap after each use, will it help? Also, the package says to store this medication at room temperature, but will storing it in the fridge help it stay fresh longer?
Tetracycline is one of those antibiotics that actually becomes toxic to the liver if it goes bad, so I assume oxytetracycline behaves the same way (couldn't find any info specific to oxytetracycline online). I obviously don't want to put our chicken's health at risk but I also don't want to waste medication or money. Oxytetracycline is pricey at our feed store, about $35 per bottle, and we will be using only a small portion of the 100 mL bottle over the next 2-3 weeks and will likely need to repeat treatment in a few months. (We are treating just one chicken for a recurrent infection.)
Excellent questions. 
