摘要 |
FIELD: chemistry.SUBSTANCE: stability is achieved by crystallising drotaverine hydrochloride in the presence of a stabilising additive of a mixture of citric acid and its sodium salt in amount of up to 1.0% of the weight of drotaverine hydrochloride fed for crystallisation. In order to protect drotaverine hydrochloride from oxidative decomposition, the composition of the solution before crystallising the end product may include additional stabilising components: trilon B, sodium metabisulphite, benzethonium chloride in amount of not more than 1.0% of the weight of drotaverine hydrochloride fed for crystallisation.EFFECT: high stability during prolonged storage.2 cl, 2 ex, 1 tbl |