초록
Carvedilol, is a nonselective $\beta$-blocking agent and it also has vasodilating properties that are attributed mainly to its blocking activity at ${\alpha}_1$-receptors. The purpose of the present study was to evaluate the bioequivalence of two carvedilol tablets, $Dilatrend^{(R)}$ tablet 12.5 mg (Chong Kun Dang Pharmaceutical Co., Ltd.) and Cadilan tablet 12.5 mg (KyungDong Pharmaceutical. Co., Ltd.), according to the guidelines of the Korea Food and Drug Administration (KFDA). The release of carvedilol from the two carvedilol formulations in vitro was tested using KP VIII Apparatus II method with pH 4.5 dissolution medium. Thirty two healthy male subjects, $25.00{\pm}3.09$ years in age and $70.71{\pm}11.35\;kg$ in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After a single tablet containing 12.5 mg as carvedilol was orally administered, blood samples were taken at predetermined time intervals and the concentrations of carvedilol in serum were determined using HPLC with fluorescence detector. The dissolution profiles of two formulations were similar in the tested dissolution medium. The pharmacokinetic parameters such as $AUC_t$, $C_{max}$ and $T_{max}$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t$, $C_{max}$ and untransformed $T_{max}$. The results showed that the differences between two formulations based on the reference drug, $Dilatrend^{(R)}$ tablet 12.5 mg, were 4.66%, 8.33% and -7.45% for $AUC_t$, $C_{max}$ and $T_{max}$, respectively. There were no sequence effects between two formulations in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log 0.8 to log 1.25 (e.g., $\log\;0.9823{\sim}\log\;1.1042$ and $\log\;1.0132{\sim}\log\;1.1875$ for $AUC_t$ and $C_{max}$, respectively). Thus, the criteria of the KFDA bioequivalence guideline were satisfied, indicating Cadilan tablet 12.5 mg was bioequivalent to $Dilatrend^{(R)}$ tablet 12.5 mg.
