Nanjing Chia Tai Tianqing Pharmaceutical Co., Ltd.

Objective: To detect the instantaneous release curve of Mirabegron sustained-release tablets by fiber-optic dissolution test system, and compared with the release data which detected by ordinary dissolution apparatus Methods: The release rates of Mirabalone sustained-release tablets in pH 6.8 phosphate buffer were detected by fiber-optic dissolution test system and ordinary dissolution apparatus Basket method was used as the dissolution apparatus, and rotation rate was 100 r · min^-1. The volume of dissolution medium was 900 mL. Results: the release behavior of self-made preparation and reference preparation were similar. The release rates determined by fiber-optic dissolution apparatus and ordinary dissolution apparatus were basically consistent. Conclusions: Compared with ordinary dissolution method, fiber-optic dissolution method is simple, fast and can obtain large amount of information, which can help to improve the efficiency of product development.

A GC method for the determination of the related substances of 2-thiophenene ethanol was established. The related substances was detected by DB624 capillary column with FID detector. The column temperature was programmed. The inlet temperature was 260 °C and FID detector temperature was set at 300 °C. The carried gas flow rate was 2.5 mL·min^-1. The results showed that, main substance and its impurities could be well separated The good linearity for related substances was obtained in the range of 20%∼200% (r≥0.990). The recovery of related substances was 95.0%∼117.6% (RSD<5.0%, n=9). The solution was stable within 16 h, and the RSDs of precision and repeatability were less than 5.0%. So, the method has good precision and high accuracy, and can be used for the detection of related substances in 2-thiophenene ethanol.

A method for the determination of the potentially genotoxic impurity 1-(1-chloroethyl)-2,3-dimethylbenzene by GC-FID was established. A DB-624 was used as capillary column (30 m×0.32 mm, 1.8 μm) (temperature programming), carrier gas flow rate was 2.0 mL·min^-1, injection temperature and FID temperature both were 280 °C. Injection volume was 1.0 μL and the split ratio was10:1. The calibration curve was well linear for 1-(1-chloroethyl)-2,3-dimethylbenzene in the range of 0.92∼13.82 μg·mL^-1 (r=0.9998). The LOD and LOQ were 0.46 μg·mL^-1 and 0.92 μg·mL^-1, resp. The average recovery was 115.7%, with RSD of 1.5% (n=9). The method is sensitive, accurate and convenient. It is suitable for the determination of the potential genotoxic impurity1-(1-chloroethyl)-2,3-dimethylbenzene.