Optimization of the Formulation of Dextromethorphan Hydrobromide Sustained-release Tablets by Orthogonal Test

OBJECTIVE:To optimize the formulation of dextromethorphan hydrobromide sustained-release tablets. METHODS: The dextromethorphan hydrobromide sustained-release tablets were prepared with HPMC as sustained release matrix. Orthogonal test was performed to optimize the formulation with in vitro accumulative drug release rate as index and the amount of HPMC and lactose as well as ethylcellulose (EC) concentration as factors. Then verification test on the in vitro drug release characteristics of the optimized tablets were performed and the influencing factors (high temperature,high light,and high moisture) were investigated as well. RESULTS: The optimized formulation of dextromethorphan hydrobromide sustained-release tablets was as follows: 30 mg HPMC,50 mg lactose,and 8% EC. The accumulative drug release rate at 8 h was above 70%. In the influencing factor test,the tablets were stable under all conditions except at high moisture condition. CONCLUSION: The optimized formulation of dextromethorphan hydrobromide sustained-release tablets is feasible.