Preparation of controlled release coated tablets of naproxen sodium

OBJECTIVE: To study the preparation of controlled release coated tablets of naproxen sodium. METHODS: Core tablet was coated with cellulose acetate which contained PEG-400 as a plasticizer for controlling membrane porosity. Uniform design was used to optimize the formulation (f2 fit factors as response variable). The dissolution test and HPLC assay method were applied to investigate the release profile and pharmacokinetics of the test tablet and reference one in rabbits. W-N method was used to evaluate the in vivo/in vitro correlation of the test tablet and reference one. RESULTS: The test tablet and reference one showed the similar in vitro release profiles (f2 = 91.29). The primary pharmacokinetic parameters of the test tablet and reference one were: AUC0∼∞ (3 763.39±502-55) μg&middoth&middotmL-1 and (4 002.80±773.86) μg&middoth&middotmL-1,tmax(5.79±0.53) h and (6.04±1.51) h, cmax (149.18 ±24.49) and (181.97±58.6) μg&middotmL-1, respectively. The relative bioavailability of the test tablet was (94.95±11.37)%. CONCLUSION: There was no significant difference between the test tablet and reference one. Bioequivalence was found between the test tablet and reference one. Significant correlation was found between in vitro dissolution and in vivo absorption of the two preparations.