The Pulsatile Microdialysis (PMD) Technology PMD is a proprietary, patented in vitro testing technology that provides frequent, real-time measurements of free, dissolved (bioavailable) drug concentrations under physiologically relevant conditions. Unlike conventional methods that measure total or solubilized drug concentrations, PMD isolates only the absorbable fraction—the form responsible for biopharmaceutical and pharmacological outcomes. PMD can measure free drug concentrations as often as every 10 seconds. It operates in situ and is suited for non-ideal media containing proteins, polymers, surfactants, dispersed phases, and subjected to varying pH, temperature, and ionic strength. This allows direct measurement in simulated GI fluids, plasma surrogates, and formulation vehicles. Conventional assays may overestimate bioavailability by including precipitated nuclei, bound drug, or solubilized species not truly available for absorption. In contrast, PMD selectively tracks the free-drug profile of dynamic processes such as supersaturation, nucleation, precipitation, redistribution, and binding or release, providing a more accurate picture of how concentrations evolve and influence absorption or drug delivery predictions. Key applications include:
• Screening supersaturating formulations (e.g., ASDs, SMEDDS) via spring-and-parachute profiles • Quantifying binding and dissociation rate constants (kon/koff) • Measuring precipitation without inflating free drug estimates • Evaluating triggered release from carriers or conjugates • Generating input for PBPK models and validating AI/ML predictions
No other platform combines PMD’s selectivity, time resolution, and in situ compatibility, making it a uniquely capable tool for formulation development, drug delivery optimization, and predictive biopharmaceutics.
