TitleExamining mechanical properties of single acetaminophen crystal using nanoindentation methods
NameParikh, Hiral (author), Mann, Adrian (chair), Klein, Lisa C. (internal member), Matthewson, M. John (internal member), Rutgers University, Graduate School - New Brunswick,
SubjectMaterials Science and Engineering,
Pharmaceutical industry--Quality control,
DescriptionThe pharmaceutical industry incurs substantial loss in revenue and consumer confidence with inefficient manufacturing practices. Large scale processing of organic compounds is challenging due to its sensitivity to environmental conditions and the unpredictable breakage behavior of tablets under applied stress. Tablet compaction and particle size reduction through milling induces variability in the end product. Variability in powder flow, stress induced transformation in polymorphic compounds, re-crystallization after compaction, and lack of content uniformity are some factors that translate into poor product quality. These challenges can be partially resolved by a better understanding of mechanical properties of crystalline pharmaceutical materials at single particle level. The endeavor of this study was to understand the breakage behavior of various planes of a single Acetaminophen crystal using nanoindentation instrumentation. The results of the study indicated that the Acetaminophen crystal is anisotropic with respect to hardness and Young’s modulus values. Analysis of the load-depth curve, discontinuities on the loading and unloading cycle were observed, as well as pop-in events during constant load intervals. Furthermore, the frequency of pop-in events on the loading depth curve was found to correlate with the elasticity of the planes in question. It was also apparent that the organic compound was sensitive to environmental conditions. Varying strain rates effects different planes of the same crystal and also in adhesion reflected sensitivity to environmental conditions. The exact mechanism by which the crystal deforms is still unknown. However it is theorized that it could be through partial dislocations and crack propagations.
NoteIncludes bibliographical references
Noteby Hiral Parikh
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.