Pharmacokinetics and relative bioequiª²valence of sustainª²released nefopam hydrochloride tablets in healthy volunteers

    CHEN Pingª²Jun, WEN Aiª²Dong, LUO Xiaoª²Xing£¬ ZHAO Lei, YANG Zhiª²Fu, WU Yin, SHEN Tong£¬ XIE Li

    1Department of Pharmacy, Xijing Hospital, 2Department of Pharmacology, School of Pharmacology, Fourth Military Medical University, Xi¬ðan 710033, China

    ¡¾Abstract¡¿ AIM: To investigate the pharmacokinetics and the bioequivalence of the nefopam hydrochloride sustainª²released tablets in 20 healthy male volunteers. METHODS: Twenty volunteers were randomly distributed into two groups by an open, randomized twoª²period crossover with seven days washout interval. A single or multi oral doses were given to the volunteers. Nefopam hydrochloride concentration was assayed by the HPLCª²MS. RESULTS: The standard curve was linear within the range of 2 and 150 ¦Ìg/L for nefopam hydrochloride, the correlation coefficient of calibration curve was 0.9998 and the minimum limit of detection in plasma was 2 ¦Ìg/L. The pharmacokinetics parameters of sustainª²released tablets or common tablets obtained from single oral dose study were as following: ¦Ñmax (72¡À18) and (105¡À25) ¦Ìg/L, Tpeak (5.1¡À0.6), (2.1¡À0.7)h, respectively; AUC(0-24 h) (907¡À340) and (865¡À287) ¦Ìg¡¤h/L. The steadyª²state pharmacokinetics parameters: AUCSS(0-24 h)(1308¡À313)and(504¡À109)¦Ìg¡¤h/L, ¦Ñmax(101¡À20) and (114¡À28)¦Ìg/L, and ¦Ñmin(29¡À13) and (20¡À12)¦Ìg/L. CONCLUSION: The results of the present study indicate that the sustainª²released tablets and common tablets are the bioequivalent (P>0.05) in healthy volunteers. ......