A Review on Metal Impurities in Pharmaceuticals

Sources of metal impurities can from anywhere in drug product as raw material which may produce using metal catalyst, excipients, process materials, Water or any solvent used, manufacturing equipment, environment, packaging materials. So, it leads to metal impurity in high amount present in final drug product that is why it is important to check the impurity level in final drug product or as well as in process also that it should be present in low or acceptable amount. Any Drug product is not completely pure, some amount of metal impurities are always present in pharmaceutical product may cause various toxicity when it will be administered. Thus it is necessary to check impurity level is present at acceptable amount. The present review gives an account of updated information about metal impurities and reviews the regulatory aspects for such metal impurities in drug substance/drug product. In addition the aim of this article is to discuss the currently used different analytical techniques for detection of metals from drug product like spectrophotometry, X – Ray florescence spectrometry, AAS, INAA, ICP – AES, ICP – MS, MP – AES, Laser Ablation – ICP – MS etc which is used for quality control of metal impurities in pharmaceuticals.

Nanostructures on Sapphire Surfaces Induced by Metal Impurity Assisted Ion Beam

The metal impurity assisted ion beam technology has shown its uniqueness and effectiveness in the formation and precise control of nanostructures on the surface of materials. Hence, the investigation in this area is vital. The morphology evolution of self-organized nanostructures induced by Fe co-deposition assisted Ar+ ion beam sputtering at a different distance from the impurity target was investigated on sapphire, using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). We also investigated the role of metal impurities on sapphire ripple formation. Experiments were carried out at an oblique angle of incidence 65° with constant ion beam current density 487 μA/cm2 and the erosion duration of 60 min at room temperature (20 °C). The introduction of Fe impurity increased the longitudinal height and roughness of the surface nanostructures. Moreover, the amounts of Fe deposited on the surface decreased with increasing distance, and the morphology of the smooth sapphire surface demonstrated a strong distance dependence. Differences in surface morphology were attributed to changes in metal impurity concentration. With an increase of impurity target distance, island-like structures gradually evolved into continuous ripples. At the same time, the orderliness of nanostructures was enhanced, the longitudinal height gradually decreased, while the spatial frequency was unchanged. In addition, there were very few metal impurities on the etched sample. During the ion beam sputtering process, island-like structures promoted the growth of ripples but destroyed their orderliness.