February 10, 2017
The UK College of Pharmacy Research Publication Highlight for January, 2017 was published in the Journal of Pharmaceutical Sciences and is titled “Characterization of Synthesized and Commercial Forms of Magnesium Stearate Using Differential Scanning Calorimetry, Thermogravimetric Analysis, Powder X-Ray Diffraction, and Solid-State NMR Spectroscopy”.
The study was led by Sean Delaney, a postdoctoral fellow in the laboratory of Dr. Eric Munson, Professor of Pharmaceutical Sciences. Posdoctoral fellows Matthew Nethercott and Manish Sethi contributed to the work as did graduate students Julie Calahan, Donia Arthur, and Nick Winquist, plus undergraduates Christopher Mays and Dan Pardue. Junghyun Kim and Dr. Gregory Amidon from the University Of Michigan College Of Pharmacy collaborated on the project.
Magnesium Stearate is a lubricant used in the manufacturing of over half the tablet formulations currently on the market. As the salt of a mixture of fats, it varies by industrial supplier and has several forms that vary in their physical-chemical properties depending on the amount of water associated with the molecules. This complicates the manufacturing process and can result in formulations with poor bioavailability or others that disrupt the manufacturing process. The team investigated various forms and commercially available sources of magnesium stearate with a range of analytical techniques to better understand the variability in, and the impact on, the physical chemical properties of this critical manufacturing additive to tablet formulations. Their findings indicate that magnesium stearate preparations vary substantially by commercial supplier in virtually everyone analytical method employed. The findings have a number of implications for pharmaceutical companies when selecting a manufacturer for magnesium stearate, its form, and how to alter their manufacturing process, specifically mixing time, when preparing tablet formulations.