摘要
The aim of this study was to investigate the stability of Carbocysteine (CBC) contained in a reference substance (RS) and in a sample of opened RHINATHIOL<sup>®</sup> 5% syrup (RNTL 5%) under the effect of some physicochemical parameters (temperature, light, time, pH, bile salts). The developed method was linear, precise and accurate according to USP 38. The co-efficient of determination R<sup>2</sup> for linearity was 0.9993. The respective RSD of intra-day and inter-day between days (1st, 2nd and 3rd day) were respectively 0.338% and the interval from 0.05% to 0.387%. The average recovery rate ranged from 98.490% to 100.450%. The detection and quantification limits were 0.0001 mg/mL and 0.001 mg/mL respectively. The method was applied to four samples of opened syrup containing CBC and the CBC content in these samples was found to be in accordance with USP 38. The CBC content in the opened sample of RNTL 5% was obtained by UV-visible spectrophotometry at 217 nm and was 4.887 g/100mL. The study of the influence of physico-chemical factors on the content of CBC in RS and RNTL 5% showed that the evolution of CBC contents in each drug matrix remained dependent on pH and temperature. However, these levels remained stable in the presence of light.
The aim of this study was to investigate the stability of Carbocysteine (CBC) contained in a reference substance (RS) and in a sample of opened RHINATHIOL<sup>®</sup> 5% syrup (RNTL 5%) under the effect of some physicochemical parameters (temperature, light, time, pH, bile salts). The developed method was linear, precise and accurate according to USP 38. The co-efficient of determination R<sup>2</sup> for linearity was 0.9993. The respective RSD of intra-day and inter-day between days (1st, 2nd and 3rd day) were respectively 0.338% and the interval from 0.05% to 0.387%. The average recovery rate ranged from 98.490% to 100.450%. The detection and quantification limits were 0.0001 mg/mL and 0.001 mg/mL respectively. The method was applied to four samples of opened syrup containing CBC and the CBC content in these samples was found to be in accordance with USP 38. The CBC content in the opened sample of RNTL 5% was obtained by UV-visible spectrophotometry at 217 nm and was 4.887 g/100mL. The study of the influence of physico-chemical factors on the content of CBC in RS and RNTL 5% showed that the evolution of CBC contents in each drug matrix remained dependent on pH and temperature. However, these levels remained stable in the presence of light.
