Indexed on: 24 Dec '05Published on: 24 Dec '05Published in: Pharmaceutical development and technology
Magnesium stearate is widely used as a lubricant in pharmaceutical dosage forms. A film of magnesium stearate, or other lubricant, around individual granules is generally considered to cause the softening of tablets. Maltodextrins were chosen as model excipients since maltodextrins possessing a series of molecular weights showed systematically changing consolidation mechanisms. As maltodextrin molecular weight increases, the plasticity of the material increases. The Hiestand Tableting Indices and other related mechanical properties were used to study the effect of magnesium stearate addition on the mechanical properties and consolidation mechanisms of single component maltodextrins. Magnesium stearate was shown to lower the tensile strengths of maltodextrin compacts. Additionally, magnesium stearate addition lowered both the Hiestand Bonding Index and the Hiestand Brittle Fracture Index. The lower values of the Hiestand Brittle Fracture Index indicate that magnesium stearate promotes greater plastic behavior in maltodextrin compacts.