Preparation of cough syrup containing dextromethorphan HBr, promethazine HCl and preliminary assessment of formulation stability

Abstract

Cough is a popular symptom because of various causes, which lead to several inconveniences in life. Dextromethorphan and promethazine are two active ingredients commonly used in combination in the treatment of coughs with many advantages such as enhanced therapeutic efficiency, limiting drawbacks of each active ingredient, and being easy to use for special patients (children, dyspepsia,…). However, currently on the Vietnamese market, there are no combined preparations of these two substances, these products are only available in foreign countries. This research is done with the goal of the simple, suitable preparation process for a syrup containing dextromethorphan HBr 15 mg and promethazine HCl 6.25 mg in each 5 ml in Viet Nam. Inoculants are evaluated according to the in-house standard criteria and appropriate testing methods included physical properties, pH, density, microbial limit, alcohol concentration, qualitative and quantitative composition medicines. Study on the stability proved the syrup remained stable after 6 months at the storage condition of 40 +/- 2 oC and 75 +/- 5% relative humidity. Formulation and preparation procedure are used to study in larger batch sizes to apply to production.