Tablet mechanics depend on nano and micro scale adhesion, lubrication and structure
2015 (English)In: International Journal of Pharmaceutics, ISSN 0378-5173, E-ISSN 1873-3476, Vol. 486, no 1-2, 315-323 p.Article in journal (Refereed) Published
Tablets are the most convenient form for drug administration. However, despite the ease of manufacturing problems such as powder adhesion occur during the production process. This study presents surface and structural characterization of tablets formulated with commonly used excipients (microcrystalline cellulose (MCC), lactose, mannitol, magnesium (Mg) stearate) pressed under different compaction conditions. Tablet surface analyses were performed with scanning electron microscopy (SEM), profilometry and atomic force microscopy (AFM). The mechanical properties of the tablets were evaluated with a tablet hardness test. Local adhesion detected by AFM decreased when Mg stearate was present in the formulation. Moreover, the tablet strength of plastically deformable excipients such as MCC was significantly decreased after addition of Mg stearate. Combined these facts indicate that Mg stearate affects the particle-particle bonding and thus elastic recovery. The MCC excipient also displayed the highest hardness which is characteristic for a highly cohesive material. This is discussed in the view of the relatively high adhesion found between MCC and a hydrophilic probe at the nanoscale using AFM. In contrast, the tablet strength of brittle materials like lactose and mannitol is unaffected by Mg stearate. Thus fracture occurs within the excipient particles and not at particle boundaries, creating new surfaces not previously exposed to Mg stearate. Such uncoated surfaces may well promote adhesive interactions with tools during manufacture.
Place, publisher, year, edition, pages
2015. Vol. 486, no 1-2, 315-323 p.
Adhesion, Atomic force microscopy, Excipients, Profilometry, Surface roughness, Tableting, lactose, magnesium stearate, mannitol, microcrystalline cellulose, Article, chemical binding, chemical structure, controlled study, drug formulation, elasticity, hydrophilicity, lubrication, mechanics, priority journal, scanning electron microscopy, strength, tablet, tablet hardness, tablet property, tablet surface
IdentifiersURN: urn:nbn:se:kth:diva-167709DOI: 10.1016/j.ijpharm.2015.03.049ISI: 000353999100034ScopusID: 2-s2.0-84928336238OAI: oai:DiVA.org:kth-167709DiVA: diva2:815902
QC 201506022015-06-022015-05-222015-06-12Bibliographically approved