Study on Pharmacokinetics and Bioequivalence of Diclotenac Potassium Sustained-Release Tablets in Dogs

OBJECTIVE To study the bioequivalence of diclotenac potassium sustained-release tablets and commercial tablets in dogs.METHODS 50 mg commercial tablet(reference)and 75 mg diclotenac potassium sustained-release tablet(test)were given to 6 healthy male dogs in a randomized two-way crossover design,respectively.The concentrations of diclotenac potassium were determined by RP-HPLC with UV detection.RESULTS The pharmacokinetic parameters of diclotenac potassium of commercial tablets and sustained-release tablets were as following:t_(max)(0.50±0.01) and(4.17±0.10) h;ρ_(max)(4.96±1.06)and(1.37±0.11) mg·L~(-1);AUC_(0～∞)(9.09±0.89) and(12.86±0.70)mg·h·L~(-1);t_(1/2)(2.33±0.84) and(7.94±1.45) h,respectively.The mean relative bioavailability of diclotenac potassium sustained-release tablets vs commercial tablets was 97.16%.CONCLUSION The two formulations are bioequivalent,regarding the estimate of AUC.The test formulation has more significant sustained-release effect than the reference formulation.