Exploring the legacy of a pharmaceutical pioneer who revolutionized how we deliver life-saving medicines
In the world of pharmaceutical research, where complex formulas and microscopic interactions determine whether life-saving medicines will work effectively, Professor Paul M. Bummer stood as both a dedicated educator and a brilliant innovator. When he passed away on May 15, 2015, at age 59, the scientific community lost more than just a respected researcher—it lost a passionate teacher who had spent 25 years unraveling one of medicine's most persistent problems: how to deliver poorly soluble drugs to where they're needed in the body. 3 7
Bummer's work focused on the microscopic world of colloids, surfactants, and lipid systems—the unsung heroes that make modern medicines possible.
His research addressed a critical challenge in drug development: many promising therapeutic compounds, especially anti-cancer agents, show excellent activity in laboratory settings but fail to become usable medicines because they don't dissolve properly in the body. Without dissolution, these drugs can't reach their targets, rendering them ineffective. Through his pioneering work, Bummer helped transform these problematic compounds into deliverable treatments, potentially improving lives while advancing the entire field of pharmaceutical sciences. 3 7
To understand Bummer's contributions, we must first venture into the microscopic universe where his work resided. Colloidal systems represent a unique state of matter where one substance is dispersed throughout another, with the dispersed particles measuring between 1 nanometer and 1 micrometer—far too small to see with the naked eye, but large enough to exhibit fascinating properties.
Microscopic view of colloidal particles
In pharmaceutical applications, colloidal systems become particularly valuable for delivering poorly soluble drugs, a category that includes many modern therapeutic compounds. When drugs won't dissolve, they can't be absorbed by the body, making them therapeutically useless regardless of their inherent biological activity. 3
Bummer's work extensively explored surfactants—molecules that solve solubility problems by acting as molecular mediators between oil-soluble and water-soluble compounds. The name "surfactant" derives from "surface-active agent," describing their ability to accumulate at interfaces and reduce surface tension.
Surfactants possess a unique dual personality: their hydrophilic (water-loving) heads gravitate toward water molecules, while their hydrophobic (water-fearing) tails seek out oil-like environments, including the surfaces of poorly soluble drug particles. When properly formulated, surfactants can assemble into organized structures called micelles, which create microscopic environments where otherwise insoluble drugs can be accommodated and delivered. 3
Throughout his career at the University of Kentucky College of Pharmacy, Bummer's research centered on practical applications of colloid and interface science to overcome drug delivery challenges. His investigations spanned multiple aspects of this complex field: 3
This work wasn't merely academic; it addressed real-world problems in drug development. By understanding how surfactants and lipids assemble and interact with drug molecules, Bummer and his team could design better delivery systems for challenging pharmaceuticals, particularly anti-cancer agents that traditionally presented significant delivery obstacles. 3
One particularly promising approach that aligned with Bummer's research is the development of nanosuspensions—finely dispersed particles of pure drug substance suspended in liquid, with each particle measuring mere nanometers in diameter. These ultra-small particles dramatically increase the surface area available for dissolution, potentially solving bioavailability problems for insoluble drugs. 4
However, nanosuspensions present their own challenges. The same high surface area that enhances dissolution also makes the system inherently unstable, with particles tending to aggregate over time. This is where Bummer's expertise in stabilizer interactions proved invaluable—identifying the right combinations of polymers and surfactants to maintain nanosuspension stability without compromising biological activity. 4
While Bummer's specific laboratory methodologies aren't fully detailed in the available sources, we can examine a relevant groundbreaking experiment from his field that exemplifies the type of challenges his work addressed. A 2016 study published in the Journal of Pharmaceutical Innovation tackled a crucial problem in nanosuspension development: simultaneously measuring the concentrations of hydroxypropyl methylcellulose (HPMC polymer) and dodecyl β-D-maltoside (DM surfactant) in nanosuspension formulations. 4
This quantification problem is more complex than it might appear. Neither HPMC nor DM contains chromophores (light-absorbing chemical groups), making them invisible to standard UV detection methods. Additionally, their wide molecular weight distributions and structural diversity create complications for traditional analytical approaches.
Without accurate measurement techniques, formulators cannot determine optimal stabilizer ratios or ensure batch-to-batch consistency, potentially compromising both stability and safety. 4
The research team developed an innovative analytical method combining size exclusion chromatography (SEC) with evaporative light scattering detection (ELSD). Their systematic approach included: 4
A Waters Ultrahydrogel 120 size exclusion column specifically designed to separate molecules based on size differences.
An isocratic (consistent composition) mobile phase of acetonitrile and water (30:70 ratio) that provided optimal separation without interfering with detection.
ELSD detection, which works by nebulizing the column effluent, evaporating the mobile phase, and detecting the remaining non-volatile particles through light scattering.
A full factorial design to identify optimal instrument settings for temperature, pressure, and gain to maximize accuracy, precision, and sensitivity.
The developed method successfully simultaneously quantified both HPMC and DM with good accuracy, precision, and reproducibility. Key findings included: 4
This methodological advance provided researchers with a powerful tool to optimize stabilizer compositions, potentially accelerating the development of more effective nanomedicines—an application perfectly aligned with Bummer's research interests in surfactant and polymer systems. 4
| Parameter | Effect on Accuracy | Effect on Precision | Effect on Sensitivity |
|---|---|---|---|
| Drift Tube Temperature | Significant improvement when increased | Moderate improvement when increased | Minor improvement when increased |
| Nebulizer Pressure | Minimal impact | Minimal impact | Significant improvement when decreased |
| Amplifier Gain | Moderate improvement when increased | Significant improvement when increased | Minor improvement when increased |
| Mobile Phase Composition | Retention Time HPMC (min) | Retention Time DM (min) | Resolution |
|---|---|---|---|
| Acetonitrile:Water (30:70) | 6.2 | 7.8 | 2.1 |
| Acetonitrile:Water (40:60) | 5.9 | 7.4 | 1.8 |
| Acetonitrile:Water (20:80) | 6.7 | 8.3 | 2.0 |
| Performance Measure | HPMC | DM |
|---|---|---|
| Linear Range (μg/mL) | 10-325 | 10-325 |
| Accuracy (% recovery) | 98.5% | 99.2% |
| Precision (% RSD) | 1.8% | 2.1% |
| Limit of Detection (μg/mL) | 5.2 | 4.7 |
| Reagent/Material | Function in Research | Example Applications |
|---|---|---|
| Lipid Excipients | Enhance delivery of poorly soluble drugs | Oral and parenteral drug formulations |
| Surfactants (DM, N-9) | Stabilize colloidal systems, reduce interfacial tension | Nanosuspensions, emulsions, micellar systems |
| Polymers (HPMC, PVP) | Modify viscosity, provide steric stabilization | Controlled release systems, nanosuspensions |
| Hydroxypropyl Methylcellulose (HPMC) | Stabilizer, viscosity modifier | Pharmaceutical nanosuspensions |
| Dodecyl β-D-Maltoside (DM) | Non-ionic surfactant with high solubility | Membrane protein studies, nanosuspensions |
| Polyvinylpyrrolidone (PVP) | Polymer stabilizer | Coprecipitates to modify drug properties |
Crucial for enhancing delivery of poorly soluble drug compounds in various formulations.
Key components for stabilizing colloidal systems and reducing interfacial tension.
Provide viscosity modification and steric stabilization in drug delivery systems.
Paul Bummer's legacy extends far beyond his specific research findings. As a four-time recipient of the University of Kentucky College of Pharmacy's Blouin Award for Excellence in Education, he shaped the minds of countless pharmacy students and graduate researchers. 3 7
He served as dissertation chair for 8 PhD and MS students and mentored 8 post-doctoral scholars, ensuring his knowledge and approach would influence subsequent generations of pharmaceutical scientists. 7
His editorial work for the journal Pharmaceutical Research, where he reviewed approximately 1,000 manuscripts over 9 years, further extended his impact on the field. 3
Colleagues remembered him as "an outspoken advocate for pharmaceutical technology and physical pharmacy" and "an encouraging champion for junior scientists." 3
Perhaps most tellingly, Bummer's commitment to education extended beyond the university walls to his two decades of volunteer work with Lexington Habitat for Humanity, where he taught volunteers of all ages the art of home building—transferring his professional skill of teaching to community service. 7
Paul M. Bummer's career exemplifies how dedicated focus on fundamental scientific questions—like how molecules assemble and interact at interfaces—can generate knowledge with profound practical implications. His work advanced our understanding of colloidal systems and interfacial phenomena, but more importantly, it contributed to solving the very practical problem of delivering effective medicines to patients who need them.
While the specific details of his experimental approaches aren't fully captured in the available literature, his documented research priorities and the broader context of his field suggest a scientist committed to both scientific excellence and practical application. Through his research, teaching, and mentorship, Bummer left the field of pharmaceutical sciences better equipped to tackle the persistent challenge of drug delivery—ensuring that promising therapeutic compounds don't fail simply because we can't deliver them to where they're needed in the body.
As pharmaceutical research continues to grapple with increasingly complex therapeutic compounds, the foundational work of scientists like Paul Bummer in understanding and manipulating colloidal and interfacial phenomena becomes ever more critical. His legacy lives on both through his scientific contributions and through the numerous students and colleagues he inspired to continue this important work.