Pharmaceutical Applications of Atomic Spectroscopy

Author(s):  
Nancy S. Lewen ◽  
Martha M. Schenkenberger
Author(s):  
J. J. Hren ◽  
S. D. Walck

The field ion microscope (FIM) has had the ability to routinely image the surface atoms of metals since Mueller perfected it in 1956. Since 1967, the TOF Atom Probe has had single atom sensitivity in conjunction with the FIM. “Why then hasn't the FIM enjoyed the success of the electron microscope?” The answer is closely related to the evolution of FIM/Atom Probe techniques and the available technology. This paper will review this evolution from Mueller's early discoveries, to the development of a viable commercial instrument. It will touch upon some important contributions of individuals and groups, but will not attempt to be all inclusive. Variations in instrumentation that define the class of problems for which the FIM/AP is uniquely suited and those for which it is not will be described. The influence of high electric fields inherent to the technique on the specimens studied will also be discussed. The specimen geometry as it relates to preparation, statistical sampling and compatibility with the TEM will be examined.


2019 ◽  
Vol 9 (01) ◽  
pp. 27-33
Author(s):  
Naveen Kumar ◽  
Sonia Pahuja ◽  
Ranjit Sharma

Humans have taken advantage of the adaptability of polymers for centuries in the form of resins, gums tars, and oils. However, it was not until the industrial revolution that the modern polymer industry began to develop. Polymers represent an important constituent of pharmaceutical dosage forms. Polymers have played vital roles in the formulation of pharmaceutical products. Polymers have been used as a major tool to manage the drug release rate from the formulations. Synthetic and natural-based polymers have found their way into the biomedical and pharmaceutical industries. Synthetic and Natural polymers can be produced with a broad range of strength, heat resistance, density, stiffness and even price. By constant research into the science and applications of polymers, they are playing an ever-increasing role in society. Diverse applications of polymers in the present pharmaceutical field are for controlled drug release. Based on solubility pharmaceutical polymers can be classified as water-soluble and water-insoluble. In general, the desirable polymer properties in pharmaceutical applications are film forming, adhesion, gelling, thickening, pH-dependent solubility and taste masking. General pharmaceutical applications of polymers in various pharmaceutical formulations are also discussed


Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 618
Author(s):  
Layla Shafei ◽  
Puja Adhikari ◽  
Wai-Yim Ching

Clay mineral materials have attracted attention due to their many properties and applications. The applications of clay minerals are closely linked to their structure and composition. In this paper, we studied the electronic structure properties of kaolinite, muscovite, and montmorillonite crystals, which are classified as clay minerals, by using DFT-based ab initio packages VASP and the OLCAO. The aim of this work is to have a deep understanding of clay mineral materials, including electronic structure, bond strength, mechanical properties, and optical properties. It is worth mentioning that understanding these properties may help continually result in new and innovative clay products in several applications, such as in pharmaceutical applications using kaolinite for their potential in cancer treatment, muscovite used as insulators in electrical appliances, and engineering applications that use montmorillonite as a sealant. In addition, our results show that the role played by hydrogen bonds in O-H bonds has an impact on the hydration in these crystals. Based on calculated total bond order density, it is concluded that kaolinite is slightly more cohesive than montmorillonite, which is consistent with the calculated mechanical properties.


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