Shear strength of pharmaceutical tablets: Theoretical considerations, evaluation and relation with the capping tendency of biconvex tablets
Publication date: 30 October 2017 Source:International Journal of Pharmaceutics, Volume 532, Issue 1 Author(s): V. Mazel, H. Diarra, V. Busignies, P. Tchoreloff Capping is a major industrial issue during pharmaceutical powder compression, especially in the case of biconvex tablets. Several articles proposed that capping was in fact a failure in shear. Shear strength should thus be interesting to study the capping tendency of a formulation. In this work, the ratio between the shear strength and the tensile strength obtained by diametral compression was first studied from a theoretical point of view considering different failure criteria. Then, a shear test usually performed on bilayer tablets was adapted to monolayer tablets. The shear strength obtained for 5 products, 2 of them having a known capping tendency, were compared with the strengths obtained during diametral compression test and uniaxial compression test. The results indicated that, for the formulations with a capping tendency, the ratio between the shear strength and diametral compression strength was lower than for the other products. Considering the mechanism of capping, the weakness in shear of these formulations explained their capping tendency. This was also linked with the mechanical anisotropy of the same formulations which was shown in the literature. In the cases studied in this article, the fundamental reason for the capping tendency was the anisotropic strength of the tablets. Graphical abstract
Abstract Laryngeal trauma from prolonged endotracheal intubation occurs in patients of all ages. Most changes are superficial and heal quickly. Injuries that are found consistently during intubation include nonspecific changes, edema, granulation tissue, ulceration, and othermiscellaneous injuries. In thispapersignificant, severe, and lasting trauma of the larynx has been classified on thebasis of theknown factors in pathogenesis, observations made atendoscopy, and photographic documentation. This classification has required introduction of new descriptive terminology: "tongues of granulation tissue," &q...
PMID: 30012011 [PubMed - in process]
PMID: 30012010 [PubMed - in process]
PMID: 30012009 [PubMed - in process]
The FDA has approved the first protease inhibitor-based single-tablet regimen for the treatment of HIV-1 infection in treatment-naive and certain virologically suppressed adult patients.FDA Approvals
Publication date: August 2018Source: The Lancet Neurology, Volume 17, Issue 8Author(s): Henk-Jan Westeneng, Ammar Al-Chalabi, Orla Hardiman, Thomas PA Debray, Leonard H van den Berg
Publication date: August 2018Source: The Lancet Neurology, Volume 17, Issue 8Author(s): Susana Carmona, Kathleen Zahs, Elizabeth Wu, Kelly Dakin, Jose Bras, Rita GuerreiroSummaryAlzheimer's disease is a genetically complex disorder; rare variants in the triggering receptor expressed on myeloid cells 2 (TREM2) gene have been shown to as much as triple an individual's risk of developing Alzheimer's disease. TREM2 is a transmembrane receptor expressed in cells of the myeloid lineage, and its association with Alzheimer's disease supports the involvement of immune and inflammatory pathways in the cause of the disease, rather th...
Publication date: August 2018Source: The Lancet Neurology, Volume 17, Issue 8Author(s): Farhat Husain, Jerry Vanatta
Publication date: August 2018Source: The Lancet Neurology, Volume 17, Issue 8Author(s):
Publication date: August 2018Source: The Lancet Neurology, Volume 17, Issue 8Author(s): Lee H Schwamm