Sinopharm Weiqida Pharmaceutical Co., Ltd.

6-Aminopenicillanic acid (6-APA), a key intermediate in the synthesis of semi-synthetic penicillin antibiotics, was subjected to forced degradation under thermal, alkaline, acidic, oxidative, and photolytic conditions. The resulting degradation products were identified by ultra high-pressure liquid chromatography-quadrupole-Exactive Orbitrap mass/mass spectrometry (UPLC-Q-Exactive Orbitrap-MS/MS) and nuclear magnetic resonance (NMR) techniques. An oxidative forced degradation of 6-APA, designated RS7, was isolated and purified using semi-preparative liquid chromatography (semi-Prep-LC). Structural characterization confirmed RS7 as penicillamine disulfide. A total of 18 related substances were identified, comprising three process-related substances (including 2 pairs of isomers), and 14 degradation products (including 5 pairs of isomers). The degradation pathways of 6-APA were proposed and summarized. For the first time, the oxidative and reductive degradation products of 6-APA were identified, including the new detection of penicillamine disulfide among its forced degradation products.

The detection and control of residual solvents directly affect the product quality and safety.Isopropylamine is one of the raw materials of sitagliptin phosphate and so far its detection has not been reported.We develop a new method for detecting isopropylamine in sitagliptin phosphate by headspace gas chromatog.Moreover, isopropylamine could be well separated from isopropanol.The column used for anal. was CP-Volamine (Agilent).The amounts of sodium chloride, ammonia water and sodium hydroxide were optimized.The concentration of limit of quantitation (LOQ) is 0.728 μg/mL and the concentration of limit of detection (LOD) is 0.340 μg/mL.The recovery rate was 90.4%-103.1% and the RSD of the recovery rate was 4.6%.Adjustments in the inlet temperature (±5°C) and the heating rate (±2°C/min) had no effect on the detection results.The method can be used to detect accurately isopropylamine in sitagliptin phosphate.

Effect of temperature on synthesis of Clavulanic acid (CA) and impurity substance G during fermentation by Streptomyces clavuligerus were investigated. Results show that fermentation at 24 °C is the most favorable for CA synthesis though the fermentation duration was 20-30 hours longer than fermentation at 26 and 28 °C. Meanwhile, the impurity substance G was only 110 mg/L in the end broth of fermentation at 24 °C, which was significantly lower than 148 and 180 mg/L of fermentation at 26 and 28 °C, respectively. Correlation of specific growth rate and CA synthesis was statistically analyzed based on data of 10 batches of industrial fermentation. Two temperature-shift strategies were investigated in 50 L fermenter. Fermentation with 26-24 °C temperature strategy achieved 5097 mg/L CA titer, meanwhile the fermentation duration was shortened 24 hours comparing with fermentation at constant 24 °C. Fermentation with 26-24 °C control strategy was validated in a 60 m³ industrial fermenter, in which 4960 mg/L of CA was achieved while impurity G substance was decreased to titer 65 mg/L from 200 to 300 mg/L of normal production.