OBJECTIVE:To prepare Diphenidol hydrochloride double-layer osmotic pump tablets,and study its in vitro release characteristics. METHODS:Double-layer compressing technique and film coating technology were conducted to prepare Diphenidol hydrochloride double-layer osmotic pump tablets. The in vitro releases of it,Difenidol hydrochloride tablets in market,self-made Difenidol hydrochloride single-layer osmotic pump tablets were compared. RESULTS:The formulation was as follow as diphenidol hydrochloride 75 mg,sodium chloride 10 mg,low-molecular-weight polyoxyethylene 15 mg and right amounts of 5% PVP K30 ethanol solution. Booster layer was high-molecular-weight polyoxyethylene 60 mg,sodium chloride 20 mg,PVP K306 mg,right amounts of magnesium stearate. 12 h cumulative release(Q)of prepared double-layer osmotic pump tablets reached 80%,and the release was in line with zero-order kinetic equation. Q15 min of Difenidol hydrochloride tablets had reached 90%;Q12 h of Difenidol hy-drochloride single-layer osmotic pump tablets was only 51.14%. CONCLUSIONS:The prepared Difenidol hydrochloride dou-ble-layer osmotic pump tablets have sustained release effect,with more complete drug release within 12 h than single-layer one.

Objective: To prepare diphenidol hydrochloride push-pull osmotic pump tablets and in-vestigate the influence of differ-ent factors on in-vitro drug release. Methods: The cumulative release of different formulas was detected. Using the cumulative release and similarity factor f2as the evaluation criterion, single factor experiment was applied to screen the core formula and coating process. Results: The drug release behavior was affected by the content of PEO in the drug containing layer, the content of NaCl and the weight gain of the coating layer. After the formula was optimized, the NaCl content in the drug containing layer was 10mg, the PEO-N10 con-tent was 15mg. In the push layer, the content of PEO-WSR303 was 60 mg, that of NaCl was 20 mg. The optimized coating liquid for-mula contained 1. 25 g·L-1PEG4000 and the coating weight gain was 7% of the core. The optimized formula fitted a zero-order equa-tion within 2-12h with the drug release equation of Q=6. 308t-2. 5037(r=0. 995 8). Conclusion: The preparation technology of di-phenidol hydrochloride push-pull osmotic pump tablets is stable, and the in-vitro drug release fits zero-order model.