Profound tabletability deterioration of microcrystalline cellulose by magnesium stearate
Magnesium stearate (MgSt) is a common lubricant used in tablet formulations to facilitate tablet manufacturing by reducing ejection force. The use of MgSt in tablet formulation is known to potentially deteriorate tabletability of plastic powders and slow down drug dissolution. Here, we report surprisingly profound deterioration in tabletability of microcrystalline cellulose by hand-mixing. We also show that the hand mixing process is highly variable. To ensure the reproducibility of tabletability assessment of powders, hand-mixing should be used with caution. For research that employs hand mixing, mixing procedure should be carefully controlled and reported. Continue on Profound tabletability deterioration of microcrystalline cellulose by magnesium stearate
Lubrication with magnesium stearate increases tablet brittleness
Tablet brittleness index (TBI) quantifies tablet fracture behavior, which strongly correlates with tablet porosity and tensile strength. The goal of this work was to quantify the influence of lubrication on tablet brittleness. Magnesium stearate was used as a lubricant. Several common tablet excipients, i.e., starch, lactose, microcrystalline cellulose (MCC), and dibasic calcium phosphate anhydrate (DCPA), and a binary mixture between lactose and MCC were studied.
Highlights
Lubrication causes higher tablet brittleness
Changes in brittleness is plasticity dependent
Brittleness increases exponentially with increasing porosity
Predicting brittleness of a mixture from individual components is possible
Tablet tensile strength (σ) and TBI at zero porosity (σ0 and TBI0) were obtained from nonlinear regression of data of all powders to evaluate the relationship between brittleness and bonding strength of pore-free tablets. The results show that lubrication by magnesium stearate led to decrease in σ0 and increase in TBI0. The effect was more profound for both a longer blending time and a higher amount of magnesium stearate. In addition, the TBI of the binary mixture was successfully predicted from the fitted parameters of lactose and MCC using the power mixing rule. Such effects of lubrication on tablet brittleness should be considered during formulation development to avoid unexpected quality issues. Continue on Lubrication with magnesium stearate increases tablet brittleness
