Electronic Thesis and Dissertation Repository


Master of Engineering Science


Biomedical Engineering


Dr. Lauren Briens


Spray-dried lactose was mixed with 4 different lubricants – magnesium stearate, magnesium silicate, stearic acid, and calcium stearate – in various concentrations. Flowability testing revealed that magnesium stearate improved powder flow until a threshold was reached, at which addition of lubricant had no effect. The addition of calcium stearate also improved flow; however, additional lubricant over the optimum amount further decreased flow. Full placebo granules were manufactured by both high shear and fluidized bed techniques. A granule comparison showed different growth mechanisms, surface morphology, particle size distribution, and flow characteristics for each manufacturing technique. The high shear granules demonstrated better overall flow properties. Granules made from both techniques were mixed with magnesium stearate in varying concentrations. Again, it was determined that after a threshold addition of magnesium stearate, there was little change in flowability. After lubricant addition, the flowability characteristics of both granule types were very similar.