Douglas R Flanagan

Douglas R Flanagan




(319) 335-8827

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Research Narrative

Dr. Flanagan’s research involves the application of diffusion principles to the analysis of dissolution processes for the development of controlled release formulations using biodegradable polymers or other polymeric delivery systems. He is also interested in the application of thermal analytical methods to the characterization of the kinetics of solid-state reactions.

Dr. Flanagan’s research has led to the development of a unified dissolution model for spherical particulate drug systems which included experimental support for the model. This model unified three other models into one model describing the diffusion layer-controlled dissolution of drug particles. This model has been extended to particles that are normally distributed in size and will be further extended to describing the dissolution behavior of non-spherical particles. These models have further application to a number of controlled release drug systems in which diffusion of drug through or in a polymeric matrix is the controlling factor in the rate of drug release. The polymeric systems involve both biodegradable polymers such as polyesters and non-degradable polymers commonly used in pharmaceutical formulation to control drug release.

Dr. Flanagan has also been recently involved in developing new methods to analyze thermoanalytical data to extract meaningful kinetic parameters for solids that undergo physical or chemical change when they are heated. There are many methods for extracting such data from thermogravimetric or differential scanning calorimetric data on solid systems. Dr. Flanagan’s research has focused on methods to extract kinetic parameters that are independent of the analysis method that can lead to a better understanding of the controlling mechanisms for solid-state reactions. His methodology has been successfully applied to the desolvation kinetics of drug solvates and will be extended to other physical and chemical process in the solid-state.