Abstract: AIM: To verify the bioequivalence be-tween sustained-released tablet of nepopam and normal one.METHODS: 18 volunteers were randomly devided into two groups.Double-periodical crossed design was used, and poly-dose of nefopam was administered to 18 volunteers following single-dose after one-week interval. The concentration of nefopam hydrochloride in serum was determinated by HPLC, and the related parameters came out through 3p97 programme. RESULTS: In the single-dose test the drug concentration of sustained-released tablet maitained 2040 mg·L^-1 for 10 h, c_max was (45.8 ±15.7) mg·L^-1, t_peak was (3.4±0.8) h, and the cor-responding parameters of normal tablet were over 20 mg·L^-1 for 7.5 h, (72.7±26.0) mg·L^-1, and (1.6 ±0.6) h.The AUC was (363.4 ±107.1) and (374.8 ±125.7) mg·h·L^-1 respectively, and F was (1.02 ± 0.25). In the poly-dose test the c_max of sustained-re-leased and normal one was (31.50±12.65) and (33.68 ±10.51) mg·L^-1, c_min was (13.4±4.4) and (10.9± 5.4) mg·L^-1, t_peak was (2.6 ±0. 6) and (1.22 ± 0.46) h, and FI was (0.77±0.26) and (1.04±0.18) respectively. CONCLUSION: The sustained-released tablet is credible and the two types of tablet are equieffec-tive in AUC.

Key words: nefopam hydrochloride, sustained-re-leased tablet, HPLC, bioequivalence