Measurement of density variations in tablets using X-ray computed tomography

Non-Conventional Applications of Computerized Tomography: Analysis of Solid Dosage Forms Produced by Pharmaceutical Industry

“…Object image is then subtracted from this empty image to resume the final image. The reasons for this correction are that: i) X-ray detectors are uneven in intensity and often more sensitive towards the centre and, ii) X-ray beam is also nonuniform, often being stronger in the centre [5]. The final images are obtained in gray scale, but it also could be manipulated by using software techniques to produce binary or multiple-colored images.…”

“…In recent years, many non-conventional uses of CT has been introduced. Some of theses, for instance, applied to pharmaceutical industry, are: a) use of X-ray tomography to study the porosity and morphology of granules [4], b) measurement of density variation in tablets [5] and c) studies of internal structures of solid dosage forms [6]. This new approach to study properties of tablets, powders, granulations and liquid filled gelatin capsule is very suitable, first, because CT could generate information that traditional technologies used in this kind of analysis could not, such as: density distribution of internal structures without destroying the sample, tablet dimensions and integrity, pore size distribution, particle shape information, investigation of official and unofficial (counterfeit) copies of solid dosage forms and, second, because CT is a nondestructive technique, allowing the use of solid dosage forms in others analysis and also requires no specimen preparation.…”

Microstructural Analysis of Porous Composite Materials: Dynamic Imaging of Drug Dissolution and Diffusion Through Porous Matrices

“…The sample is placed on a precision turntable between a high power X-ray source and a detector array (line or area array), which is used to measure the intensities of the diverging X-ray beam transmitted through the sample (12,15). Multiple attenuation coefficient values, which correlate to the degree of attenuation of the Xrays, are obtained as the sample is rotated relative to the Xray beam (to obtain multiple sets of attenuation coefficients from different viewing angles) (12,16,17). This raw data can be converted to pixel greyscale data, which a mathematical algorithm can translate into two-dimensional grey-scale radiograph or projection images (12,15).…”

“…Multiple attenuation coefficient values, which correlate to the degree of attenuation of the Xrays, are obtained as the sample is rotated relative to the Xray beam (to obtain multiple sets of attenuation coefficients from different viewing angles) (12,16,17). This raw data can be converted to pixel greyscale data, which a mathematical algorithm can translate into two-dimensional grey-scale radiograph or projection images (12,15). Furthermore, the computer system can be calibrated so that values are assigned to certain materials.…”

Quantification of Swelling and Erosion in the Controlled Release of a Poorly Water-Soluble Drug Using Synchrotron X-ray Computed Microtomography

“…Synchrotron radiation X-ray computed microtomography (SR-μCT) has previously been used to explore the microstructural characteristics of tablet formulations indicating the fracture patterns of tablets prepared under different compositions and compaction pressures and to determine the density distribution of compressed dosage forms (20)(21)(22)(23)(24).…”