CAMP December Newsletter: Page 7
The cross-sectional view of a dry-coated tablet with its structural components (colored core and outer layers) and interfaces. The surface of the top outer layer of each tablet is branded.
CAMP Professor Cetin Cetinkaya and his group, in the Photo-Acoustics Research (PAR) Laboratory at Clarkson, have developed a set of noncontact / nondestructive methods to test pharmaceutical tablets. Research for monitoring, characterizing, and evaluating tablets’ mechanical properties has been motivated because these properties play a key role in areas such as drug bioavailability, stability, and shelf life. The program supports the main objectives of the Quality by Design (QbD) and Process Analytical Technology (PAT) initiatives of the U.S. Food and Drug Administration (FDA).
One of Professor Cetinkaya’s projects is to develop a non-destructive technique for determining the geometric and mechanical properties of dry-coated tablets. A dry-coated tablet is a solid dosage form with a controlled drug-release system, which consists of a core and an outer layer. See Figure 3. Two contact ultrasonic techniques (pitch-catch and pulse-echo measurement modes) are being used to measure and report the properties of all the structural components of a set of experimental tablets. The thicknesses of the outer layers of the sample tablets are used to obtain the eccentricity of the core tablets. The two approaches are then compared in regards to their effectiveness in obtaining these properties of the sample dry-coated tablets. Professor Cetinkaya is also using his new proposed approach to determine the thicknesses of the outer layers. Professor Cetinkaya’s new approach has potential for in-die real-time monitoring of compaction presses and for applications in pharmaceutical manufacturing.
Professor Cetinkaya is also investigating a noncontact / nondestructive air-coupled acoustic technique for potential use in determining the mechanical properties of bilayer tablets. In the reported experiments, a bilayer tablet is vibrated via an acoustic field of an air-coupled transducer in a frequency range sufficiently high to excite several vibrational modes (harmonics) of the tablet. The tablet’s vibrational transient responses, at a number of measurement points on the tablet, are acquired by a laser vibrometer in a noncontact manner. An iterative computational procedure based on the finite element method is utilized to extract the Young’s modulus, the Poisson’s ratio, and the mass density values of each layer material of a bilayer tablet, from a subset of the measured resonance frequencies. For verification purposes, a contact ultrasonic technique based on the time-of-flight data of the longitudinal (pressure) and transverse (shear) acoustic waves in each layer of a bilayer tablet is also utilized. The extracted mechanical properties from the air-coupled acoustic data agree well with those determined from the contact ultrasonic measurements.
Clarkson Professor Sulapha Peethamparan Recognized as a Leading Educator and Scholar by the National Science Foundation
Professor Sulapha Peethamparan
Clarkson University faculty member Sulapha Peethamparan, Assistant Professor of the Civil and Environmental Engineering Department, received this month the NSF CAREER Award from the National Science Foundation. The Faculty Early Career Development (CAREER) program grants the National Science Foundation's most prestigious awards to professors in the early stages of their careers. The award supports the educational activities of teacher-scholars who effectively integrate research and education within the context of the mission of their organization. These activities promise to build a solid foundation for a lifetime of contributions to research and education. Professor Peethamparan’s proposal, titled “Mechanisms of Hydration Kinetics and Property Evolution in Activated Slag and Fly Ash Multi-Phase Sustainable Binder Systems,” earned her the special distinction from the NSF. In the proposed research, Professor Peethamparan and her students will conduct experimental and modeling based studies to understand the microscale and nanoscale behavior of activated/cement-less concrete material systems. This work is expected to revolutionize the construction industry with better performance, a lower CO2 foot print, and lower embodied energy.