We performed kinetics of cefquinome in goats at dose rate of 1 mg/kg body weight but plasma sample did not revealed any detection of drup though HPLC analysis. Further dose rate was increased upto 10mg/kg and study eas performed, which result to detection of drug upto 2 hours only with lesser peak concentration in plasma. The result what we found are different from many study published in various species of animals. Can any one can guide me further.
hi jatin. what is route of drug administration : oral or intravenous or any other ?
if oral, there is possibility that your drug bioavailability is poor, due to poor absorption or extensive hepatic first pass. In that case you can administer drug in goat via IV or IM route and at higher doses.(10mg/kg, if safe) and then take samples and analyse them.
also their is possibility that your HPLC method is not that much sensitive, to measure drug levels in plasma or your extraction method is not efficient. What is recovery of drug from plasma samples and what is LLOQ of your analytical method??????
you should be sure on your method first. if sensitive is not good, you can develop more sensitive analytical method eg. LC-MS
also check whether the method you adopted for dosing is correct. dose administration is also very important step, if error occurs here then also pk results vary considerably.
check whether there are any stability issues with your drug in plasma.?
do stability studies in plasma samples and if their is any instability determine reason behind that using several stabilization approaches like pH adjustment or use some enzyme inhibitors.
There is issue for cefquinome sulphate kinetic. Same thing was observed. Oral route should be deleted from the study. You can perform IM kinetics. We tried in goat at dose rate of 20mg/kg and obtained concentration variably upto 6-8 hours.
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