| Dissertation note |
Carvedilol, is a class-II, non-biowaivered drug, with low solubility. It is a candidate for several in-vivo studies including bioavailability and bioequivalence of generic versus standard, and also for testing performance of modified release products. Single dose pharmacokinetic study was performed on 12 healthy dogs using 25mg Carvedilol tablets. The objective of this study was to perform pharmacokinetic and biopharmaceutic study in the dog model for Carvedilol. The animals were selected after screening by veterinary practitioner. Blood samples were collected after 15min, 30min, 1 hr, 1.5 hr, 2 hrs, 4 hrs, 6 hrs, 8 hrs, 12 hrs and 24 hrs via an in-dwelling catheter from the cephalic vein of the animals along with one base line sample taken before drug administration. The plasma samples obtained by centrifugation were analyzed by HPLC quantitative method after checking the reproducibility and linearity of the standard curve using the standards prepared in dog plasma. Pharmacokinetic parameters were calculated by using APO software, and using appropriate compartmental pharmacokinetic model. The data derived from this study was analyzed using descriptive statistics and the observed results were compared with the published literature. The pharmacokinetic parameters investigated show that peak plasma concentration was 72.33±32.84 ng/ml, elimination half life of 1.84±2.42 hrs, Mean Residence Time was 2.98±0.96hrs, Volume of distribution of 0.57±0.6 l/kg and time to peak plasma concentration of 1.77±0.31hrs. The study defends the older proposition by pharmacokineticists that the Carvedilol shows unpredictable absorption kinetics in dogs and a few of the parameters also relate with the published finding on the Carvedilol pharmacokinetics in human. The delay in absorption and significant lag time of 1.23hrs was consistent in all subjects. The study elaborated the prospects of the possibility of using animal studies to achieve predictable pharmacokinetics of the drugs without involving human subjects.
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