During the synthesis of the bulk drug Raloxifene hydrochloride, eight impurities were observed, four of which were found to be new. All of the impurities were detected using the gradient high performance liquid chromatographic (HPLC) method, whose area percentages ranged from 0.05 to 0.1%. LCMS was performed to identify the mass number of these impurities, and a systematic study was carried out...

Information about waste water from the manufacture offibreboard is given, and in this connection a classification of suspended and dissolved impurities occurring in the waste water of fibreboard mills is made. The influence on the concentration and the total amount of such impurities are discussed as a function of the extent of closing of the process wa ter system. Various methods of treatment ...

synthesis of zinc dialkyldithiophosphate (zddp) consists of two stages. in the first stage, phosphorus pentasulfide reacts with an alcohol to give dialkyldithiophosphoric acid. in the second stage, the acid is neutralized by zinc oxide. in addition  to the product, some impurities are also formed which affect the quality of the final product. if we can determine the chemical structure of these ...

A profile of impurities in bortezomib anhydride, produced by a recently developed convergent technology, has been characterized. HPLC-MS analysis of the drug essence revealed three impurities: an epimer of bortezomib, resulting from partial racemization of l-phenylalanine's stereogenic center during the chemical synthesis, and two epimeric products of oxidative degradation of bortezomib, in whi...

Production of recombinant proteins generates a variety of process-related impurities. The multistep manufacturing processes may introduce many potential contaminants into the final pharmaceutical products. These residual impurities and contaminants can potentially impact the protein stability significantly. In this short review, the authors intend to discuss major sources and types of residual ...

An unidentified peak in a drug substance or drug product chromatogram raises many questions. What is the impurity? What is the source of the impurity? How much impurity is there? Can the impurity level be reduced or eliminated? Is the impurity toxic? What do we do now? The answers to these questions are typically provided by scientists in chemistry, manufacturing and controls (CMC) and nonclini...

Two unknown impurities were detected in verapamil hydrochloride bulk drug using isocratic reversed-phase high performance liquid chromatography (HPLC). These impurities were isolated by preparative HPLC. Spectral data for the isolated impurities were collected. Based on the spectral data derived from two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy and mass spectrometry (MS), im...

UNLABELLED BACKGROUND Clematichinenoside AR is a promising lead compound for the treatment of rheumatoid arthritis. A systematic research for the related impurities in AR bulk samples is still lacking. For the safe use of this natural product in future clinical practice, the structure and content of each constituent, including the main ingredient as well as the impurities in AR bulk sample m...

Lisinopril is a drug of the angiotensin-converting enzyme (ACE) inhibitor class that is primarily used in the treatment of hypertension. During the scale-up of the lisinopril process, one unknown impurity was observed and is identified. The present work describes the origin, synthesis, characterization, and control of this impurity. This paper also describes the synthesis and characterization o...