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Atomic Force Microscopy Method Development for Surface Energy Analysis

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Atomic Force Microscopy Method Development for Surface Energy Analysis University of Kentucky UKnowledge University of Kentucky Doctoral Dissertations Graduate School 2011 ATOMIC FORCE MICROSCOPY METHOD DEVELOPMENT FOR SURFACE ENERGY ANALYSIS Clare Aubrey Medendorp University of Kentucky, [email protected] Right click to open a feedback form in a new tab to let us know how this document benefits ou.y Recommended Citation Medendorp, Clare Aubrey, "ATOMIC FORCE MICROSCOPY METHOD DEVELOPMENT FOR SURFACE ENERGY ANALYSIS" (2011). University of Kentucky Doctoral Dissertations. 185. https://uknowledge.uky.edu/gradschool_diss/185 This Dissertation is brought to you for free and open access by the Graduate School at UKnowledge. It has been accepted for inclusion in University of Kentucky Doctoral Dissertations by an authorized administrator of UKnowledge. For more information, please contact [email protected]. ABSTRACT OF DISSERTATION Clare Aubrey Medendorp The Graduate School University of Kentucky 2011 ATOMIC FORCE MICROSCOPY METHOD DEVELOPMENT FOR SURFACE ENERGY ANALYSIS ABSTRACT OF DISSERTATION A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the College of Pharmacy at the University of Kentucky By Clare Aubrey Medendorp Lexington, Kentucky Director: Dr. Tonglei Li, Professor of Pharmaceutical Sciences Lexington, Kentucky 2011 Copyright © Clare Aubrey Medendorp 2011 ABSTRACT OF DISSERTATION ATOMIC FORCE MICROSCOPY METHOD DEVELOPMENT FOR SURFACE ENERGY ANALYSIS The vast majority of pharmaceutical drug products are developed, manufactured, and delivered in the solid-state where the active pharmaceutical ingredient (API) is crystalline. With the potential to exist as polymorphs, salts, hydrates, solvates, and co- crystals, each with their own unique associated physicochemical properties, crystals and their forms directly influence bioavailability and manufacturability of the final drug product. Understanding and controlling the crystalline form of the API throughout the drug development process is absolutely critical. Interfacial properties, such as surface energy, define the interactions between two materials in contact. For crystal growth, surface energy between crystal surfaces and liquid environments not only determines the growth kinetics and morphology, but also plays a substantial role in controlling the development of the internal structure. Surface energy also influences the macroscopic particle interactions and mechanical behaviors that govern particle flow, blending, compression, and compaction. While conventional methods for surface energy measurements, such as contact angle and inverse gas chromatography, are increasingly employed, their limitations have necessitated the exploration of alternative tools. For that reason, the first goal of this research was to serve as an analytical method development report for atomic force microscopy and determine its viability as an alternative approach to standard methods of analysis. The second goal of this research was to assess whether the physical and the mathematical models developed on the reference surfaces such as mica or graphite could be extended to organic crystal surfaces. This dissertation, while dependent upon the requisite number of mathematical assumptions, tightly controlled experiments, and environmental conditions, will nonetheless help to bridge the division between lab-bench theory and successful industrial implementation. In current practice, much of pharmaceutical formulation development relies on trial and error and/or duplication of historical methods. With a firm fundamental understanding of surface energetics, pharmaceutical scientists will be armed with the knowledge required to more effectively estimate, predict, and control the physical behaviors of their final drug products. KEYWORDS: contact angle, atomic force microscopy, polymorphs, crystal habit, surface energy Multimedia Elements Used: JPEG (.jpg); Bitmap (.bmp); TIF (.tif); GIF (.gif). Clare Aubrey Medendorp ____________________________________________ Student's Signature August 2011 ____________________________________________ Date ATOMIC FORCE MICROSCOPY METHOD DEVELOPMENT FOR SURFACE ENERGY ANALYSIS By Clare Aubrey Medendorp Tonglei Li ____________________________________________ Co-Director of Dissertation Paul Bummer ____________________________________________ Co-Director of Dissertation Jim Pauly ____________________________________________ Director of Graduate Studies August 2011 ____________________________________________ Date RULES FOR THE USE OF DISSERTATIONS Unpublished dissertations submitted for the Doctor's degree and deposited in the University of Kentucky Library are as a rule open for inspection, but are to be used only with due regard to the rights of the authors. Bibliographical references may be noted, but quotations or summaries of parts may be published only with the permission of the author, and with the usual scholarly acknowledgments. Extensive copying or publication of the dissertation in whole or in part also requires the consent of the Dean of the Graduate School of the University of Kentucky. A library that borrows this dissertation for use by its patrons is expected to secure the signature of each user. Name Date DISSERTATION Clare Aubrey Medendorp The Graduate School University of Kentucky 2011 ATOMIC FORCE MICROSCOPY METHOD DEVELOPMENT FOR SURFACE ENERGY ANALYSIS DISSERTATION A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the College of Pharmacy and Economics at the University of Kentucky By Clare Aubrey Medendorp Lexington, Kentucky Director: Dr. Tonglei Li, Professor of Pharmaceutical Sciences Lexington, Kentucky 2011 Copyright © Clare Aubrey Medendorp 2011 for Joseph, Jopatrice, and Frank ACKNOWLEDEGEMENTS This dissertation would not have been possible without the support of numerous individuals. First, I would like to thank my advisor Dr. Tonglei Li for the opportunity to study under his leadership. His guidance, support, and patience contributed towards my scientific education and professional development. I would also like to thank my co- advisor Dr. Paul Bummer for his support. His enthusiasm and passion for developing scientist creates a rewarding environment to work in. I would also like to thank my dissertation committee: Dr. Brad Anderson and Dr. Carolyn Brock for their time, support, and contributions to my development and the advancement of this project. I would like to thank Dr. Constance Wood for her training and guidance in statistics. Many thanks to the PhRMA Foundation and Computational and Computer Sciences program at the University of Kentucky for their financial support to complete my dissertation. On a personal note, I would like to thank all of the members of the Li lab, Matt Swadley, Sihui Long, Alessandra Mattei, Shaoxin Feng, and Hua Zhang. I would especially like to thank Christin Hollis for her support and friendship. I would like to thank several colleagues at Merck for their support. I would like to thank my family and friends for their love and support. They continued to believe in me and push me towards professional and personal development. I would like to thank my loving husband, Joseph, without him, this dissertation would not have been possible. Thank you for being extremely supportive and caring. Thank you! x TABLE OF CONTENTS ACKNOWLEDEGEMENTS ............................................................................................. x List of Tables ................................................................................................................... xiv List of Figures................................................................................................................ xviii List of Abbreviations ....................................................................................................... xxi Chapter 1 - Introduction...................................................................................................... 1 1.1 Dissertation Purpose ................................................................................................. 1 1.2 Review of Surface Energetics................................................................................... 1 1.3 Current State-of-the-Art............................................................................................ 2 1.4 Objectives ................................................................................................................. 9 1.4.1 Specific Aim 1 ................................................................................................... 9 1.4.2 Specific Aim 2 ................................................................................................. 11 Chapter 2 – Contact Angle................................................................................................ 13 2.1 Contact Angle and Young’s Equation .................................................................... 13 2.2 Review of the Geometric Mean and Indirect Models............................................. 16 2.2.1 Fowkes ............................................................................................................. 20 2.2.2 Van Oss, Chaudhury, Good ............................................................................. 20 2.2.3 Owens-Wendt-Rabel-Kaelble.......................................................................... 23 2.2.4 Neumann.........................................................................................................
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