Colloid Science

I gained my PhD in colloid chemistry in 1990 by inventing a method to determine very small electrophoretic mobilities of dispersions in non-polar media. I named the method Phase Analysis Light Scattering (PALS). Today, PALS is the de facto method to measure zeta potential of a wide variety of colloids in many industries. It has been commercialized by a half-dozen leading instrumentation companies. My doctoral studies were under the supervision of Brian Vincent – one of the world’s foremost colloid scientists. His research group is considered to have been a world-class center of excellence. I didn’t know this when I first started. The following table highlights my areas of expertise. It is not exhaustive but is intended to emphasize the key areas of the science that I can offer greatest value as a technical consultant.

Liquid suspensions Formulation
Stability Characterization
Surfactants Particle size
Zeta potential Aggregation

In senior high school in the early 1980s my chemistry teacher demonstrated a phenomenon that fascinated me. At the time, I had no idea that it would be the focus of my doctoral research. A voltage was applied to an opaque orange liquid in a glass U-tube. After a few minutes the liquid became clear at one end. I had just observed electrophoresis of particles dispersed in a liquid – a colloid. My project was partially funded by Glaxo Group Research (now GlaxoSmithKline R&D). Glaxo’s interest was to understand the role of surface charge in suspensions of micronized drugs in chlorofluorocarbons and hydrofluoroalkanes (HFAs) used metered-dose inhalers (MDIs). Some people claim the particles to be too large to be considered colloidal but, nevertheless, the classical concepts of colloid stability can be applied. After my PhD studies and some post-doctoral research, I began working for Glaxo in 1993 in the Respiratory Product Development department. Except for a short hiatus in the early 2010s, my career focused on HFA-based MDIs. However, during my time with the company I was able to leverage my colloid chemistry expertise for a variety of dosage forms.

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