Formulation Studies of a New Noscapine Embonate Preparation

Abstract

Noscapine embonate (l:l), a new noscapine pro drug, was found to be very slightly soluble in water in the approximate pH range 4 to 7. Below t his range, the salt began to decompose and release noscapine. When the embonate was suspended in water with polyvidone at pH 5.0 to 5.5, suspensions containing spherical microparticles were produced. Increasing the amount of polyvidone caused the embonate to dissolve completely. Polyvidone had a marked effect on the stability of the suspensions. When 0.5% of polyvidone was used with conventional flavouring agents, the average particle size of the salt was about 2 to 3 μm. No appreciable change in size was observed during a 4 week period. The particles settled slowly and the sediment was easy to redisperse after 6 months' storage. The taste of a formulation containing noscapine embonate and flavouring agents was compared with that of the most popular liquid noscapine hydrochloride preparation in Finland. The formulation developed was significantly more acceptable than the reference preparation (P7< 0.01).