Abstract
The purpose of this study was to evaluate the bioequivalence of two nateglinide tablets, $PASTIC^{(R)}$ tablet (ILDONG Pharm. Co., Ltd., Seoul, Korea, reference drug) and $GLUNATE^{(R)}$ tablet (ILHWA. Co., Ltd., Seoul, Korea, test drug), according to the guidelines of Korea Food and Drug Administration (KFDA). Thirty-five healthy male volunteers, $23.1{\pm}2.3$ years in age and $69.2{\pm}8.8\;kg$ in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After a tablet containing 90 mg of nateglinide was orally administrated, blood was taken at predetermined time intervals over a period of 8 hr and concentrations of nateglinide in plasma were monitored using LC-MS/MS. Pharmacokinetic parameters such as AUCt (the area under the plasma concentration-time curve from time 0 to 8 hr), $C_{max}$ (maximum plasma drug concentration) and $TC_{max}$ (time to reach $CC_{max}$) were calculated and analysis of variance (ANOVA) test was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t$ and $C_{max}$ and untransformed $T_{max}$. The 90% confidence intervals of the $AUC_t$ ratio and the $C_{max}$ ratio for $GLUNATE^{(R)}/PASTIC^{(R)}$ were ${\log}1.0782{\sim}{\log}1.1626$ and ${\log}0.9621{\sim}{\log}1.1679$, respectively. Since these values were within the acceptable bioequivalence intervals of ${\log}0.80{\sim}{\log}1.25$, recommended by KFDA, it was concluded that $GLUNATER^{(R)}$ tablet was bioequivalent to $PASTIC^{(R)}$ tablet, in terms of both rate and extent of absorption.
