Six impurities in pantoprazole sodium bulk drug substance were detected by a simple high performance liquid chromatographic method (HPLC) whose area percentage ranged from approximately 0.05 to 0.34%. Liquid chromatography-mass spectrometry (LC-MS) was performed to identify the molecular weight of the impurities. A thorough study was undertaken to characterize these impurities. These impurities...

The objective of the current study is to develop a validated, specific and stability-indicating reverse phase liquid chromatographic method for the quantitative determination of genotoxic impurities in the drug substance imatinib mesylate. This report includes a brief review of the toxicology of impurities in imatinib mesylate and the strategies used to set acceptance criteria for genotoxic imp...

There is an ever increasing interest in impurities present in APIs. Now days, not only purity profile but also impurity profile has become mandatory according to various regulatory authorities. In the pharmaceutical world, an impurity is considered as any other inorganic or organic material, or residual solvents other than the drug substances, or ingredients, arise out of synthesis or unwanted ...

Sertindole (1), an atypical anti-psychotic drug is used for the treatment of schizophrenia. During the laboratory optimization and later during its bulk synthesis the formation of various impurities was observed. The impurities formed were monitored and their structures were tentatively assigned on the basis of their fragmentation patterns in LC-MS. Most of the impurities were synthesized and t...

A two-step HPLC separation that combines isocratic and gradient elution has been developed for the analysis of trace impurities in fatty alcohol ethoxylates (FAEs). Quantitative estimates of the early eluting impurities were obtained from a calibration curve based on the responses of an evaporative light scattering detector (ELSD). Isocratic conditions were used to elute the impurities and grad...

We present ab initio calculations of E F G s at impurities in a T i 0 2 crystal. They are directly calculated f rom the self consistent charge distribution which is determined by the K K R method within the muffin-tin approximation and based on the local density approximation. Impurities in the crystal are simulated by the super-cell method. Considering the charge state of Sc, Ti, Nb, Cd, Ta im...

Reversed-phase liquid chromatography coupled with electrospray ionization tandem mass spectrometry (ESI-MS/MS) was used to characterize impurities in cefpodoxime proxetil, an ester-modified prodrug. Based on the mechanisms by which cephalosporins are degraded, stress tests were designed and performed. The bulk material and capsule were eluted through a C18 column with formic acid-methanol-water...

Thin films of Na with Fe, Co, and Ni impurities are investigated. The magnetization of the impurities is measured by means of the anomalous Hall resistance. Fe and Co show a moment of about 6mu(B), while for Ni no moment is detected. Furthermore, the magnetic dephasing of the conduction electrons is measured by means of weak localization. The dephasing rate 1/tau(phi) of the 3d impurities diffe...

This study addresses the influences of uncertain amounts of residual impurities in the computation and experimental determination of ignition-delay times in hydrogen-air mixtures in shock tubes. Experimental methods for quantifying impurities in shock tubes are described and utilized. These methods are utilized to infer an equivalent amount of impurities as a function of the initial temperature...