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Ira Shea Buckner, Ph.D.
Assistant Professor
420 Mellon Hall
T 412.396.1006
E buckneri@duq.edu
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| Educational Background |
I earned my Ph.D. in Pharmaceutics under Dale Eric Wurster at the University of Iowa in 2008 and my B.S. in chemistry from Illinois State University. Prior to graduate school, I spent almost 3 years working in preformulation at Abbott Laboratories. I have diverse scientific interests in the areas of solid-state and physical chemistry as they relate to pharmaceuticals. Over the years, I have performed research in a variety of areas including surface characterization of pharmaceutical materials, amorphous-to-crystal transition kinetics, physical characterization methods (such as specific surface area), and several types of calorimetric analysis. My laboratory is being equipped to perform various physicochemical characterization experiments, especially in relation to solid dosage form development. We continue to develop expertise in physical, mechanical and calorimetric characterization and analysis. The current direction of my research is described below.
Research Interests
My research is related to the general area of pharmaceutical development. Specifically, we are studying the ways in which pharmaceutical solids respond to mechanical energy during processing. Pharmaceutical processing steps, such as milling, compaction, and granulation, expose the materials being processed to mechanical energy of varying intensity. Ideally, the materials will respond only with physical changes that facilitate further processing and final delivery of the active ingredient. However, this sort of positive result is often achieved without detailed understanding of the molecular and particle-level processes responsible. Ignoring underlying processes, such as particle-deformation and inter-particle bonding, often leads to inefficient development and potentially-costly complications. Better understanding of how materials respond to mechanical energy during processing will not only make product development more deliberate, but will allow problems to be predicted and avoided more effectively.
Specific projects designed to study positive responses will focus on tablet formation or powder compaction. Materials typically respond to mechanical energy differently during compaction depending on the nature of the other materials present. It is difficult to predict the tableting behavior of a new formulation directly from the properties of the individual components. One approach we will use to address this problem is to control the physical arrangements of the powders being compacted in ways that allow the behavior of specific materials in a powder mixture to be observed. Translating individual behaviors to composite behavior would be very valuable for development of new materials into tablet dosage forms. This research will be particularly valuable for development of complicated, controlled delivery-type tablets.
In addition to the desired responses exhibited by materials during mechanical processing, a number of negative outcomes may result. Mechanical energy input can cause materials to react in ways not observed under less stressful conditions. Phase changes, such as decrystallization or crystal form modification, and various chemical reactions have been observed during processing, and are usually unforeseen when they occur. Powder compaction will be used to study the undesirable consequences of mechanical processing. Specifically, phase transformation as a result of compaction will be investigated. The ultimate goal is to attain a predictive understanding of why certain materials are prone to phase conversion when formed into tablets. Characterization tools predictive of mechanically-induced instability would be very valuable in dealing with new pharmaceutical materials. This research is also expected to facilitate the development of strategies for minimizing the risk associated with mechanically-sensitive materials.
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