TY - JOUR
T1 - Ultrasonic approach for viscoelastic and microstructure characterization of granular pharmaceutical tablets
AU - Vahdat, Armin Saeedi
AU - Vallabh, Chaitanya Krishna Prasad
AU - Hancock, Bruno C.
AU - Cetinkaya, Cetin
PY - 2013
Y1 - 2013
N2 - The mechanical properties of a solid dosage, defined by its granular micro-structure and geometry, play a key role in its dissolution profile and performance. An ultrasonic method for extracting the viscoelastic material properties and granular structure of drug tablet compacts is introduced and its utility is demonstrated for tablet compacts made of microcrystalline cellulose (MCC), lactose monohydrate, and sodium starch glycolate as well as magnesium stearate as lubricant. The approach is based on the effect of viscoelasticity and internal micro-structures on the frequency-dependent attenuation of an ultrasonic wave propagating in a granular medium. The models for viscoelastic (a two-parameter Zener model) and scattering attenuation (Rayleigh model) mechanisms are employed. The material parameters including viscoelastic and scattering parameters (average Young's modulus, stress and strain relaxation time constants, and the Rayleigh scattering material parameter) and grain size distribution with a known distribution profile are extracted by an optimization algorithm based on the least square method. The results also indicate good agreement between experimentally and computationally determined phase and group velocities in compacted samples. It is found that the effects of both attenuation mechanisms are present and the extracted grain size distribution parameters are in good agreement with the optically determined values.
AB - The mechanical properties of a solid dosage, defined by its granular micro-structure and geometry, play a key role in its dissolution profile and performance. An ultrasonic method for extracting the viscoelastic material properties and granular structure of drug tablet compacts is introduced and its utility is demonstrated for tablet compacts made of microcrystalline cellulose (MCC), lactose monohydrate, and sodium starch glycolate as well as magnesium stearate as lubricant. The approach is based on the effect of viscoelasticity and internal micro-structures on the frequency-dependent attenuation of an ultrasonic wave propagating in a granular medium. The models for viscoelastic (a two-parameter Zener model) and scattering attenuation (Rayleigh model) mechanisms are employed. The material parameters including viscoelastic and scattering parameters (average Young's modulus, stress and strain relaxation time constants, and the Rayleigh scattering material parameter) and grain size distribution with a known distribution profile are extracted by an optimization algorithm based on the least square method. The results also indicate good agreement between experimentally and computationally determined phase and group velocities in compacted samples. It is found that the effects of both attenuation mechanisms are present and the extracted grain size distribution parameters are in good agreement with the optically determined values.
KW - Granular pharmaceutical solid dosage
KW - Mechanical properties grain size distribution
KW - Non-destructive characterization techniques
KW - Rayleigh scattering
KW - Viscoelasticity
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U2 - 10.1016/j.ijpharm.2013.06.045
DO - 10.1016/j.ijpharm.2013.06.045
M3 - Article
C2 - 23820132
AN - SCOPUS:84884128888
SN - 0378-5173
VL - 454
SP - 333
EP - 343
JO - International Journal of Pharmaceutics
JF - International Journal of Pharmaceutics
IS - 1
ER -