What Happens When You Swallow a Hydrogel Pill?
Carroll, Katherine; Connolly, Rachel; Hearn, Kaitlin; Yasin, Imran
The scientific world has limited knowledge on tablet properties, so scientists want a reliable method to investigate these properties and their effects on the drug release profile. We developed a model that is based on experimental data and used for various matrix combinations. In COMSOL, we modeled how the three phases of a hydrogel – swelling, eroding and diffusing – facilitated the overall delivery of a given drug. We used the principles of mass transport and solid mechanics, respectively, to model the delivery of the drug in the body as well as the erosion and swelling of the hydrogel. In COMSOL, a university licensed software program, we modeled a semi-overall shaped hydrogel through a 2D axisymmetric model. We initially modeled the geometry at its initial, non-deformed shape with the mass fractions of the water, drug, and polymer are at their initial values. The geometry deformed with time as swelling and erosion affect the polymer matrix. Using this geometry, we modeled and analyzed percent drug release, the mass of water inside the matrix, and mass of drug and polymer release over time. We then used past research data to evaluate and to understand texture analysis and to model phenomena of multiple diffusing species from a matrix. To validate our model, we compared our modeling outcomes with experimental results to understand how successfully our model depicts the experimental data. Finally, we conducted a sensitivity analysis to determine how various parameters independently affected our results. Based on our design objectives, our model aligned with our initial goals. We successfully modeled the swelling and erosion of a hydrogel matrix over time. We also effectively modeled the release of the drug from the polymer-drug matrix. We combined these two processes in COMSOL. With the results, we were able to post-process our solution by refining our mesh and conducting a sensitivity analysis. The results of our study are limited to a set of assumptions made about the geometry. These assumptions include the use of a 2D model for a 3D delivery process and negligible velocity in the environment. Therefore, while the model provides a realistic analysis of hydrogel drug delivery, some environmental factors may influence the overall outcome for each user. Using mass transport and solid mechanics to model the three phases of the hydrogel, we were able to create a realistic model of this drug delivery process. Our model allows scientists and engineers investigate various matrix properties and their effects on the tablet's drug release profile. Without invasive procedures, they can use our model to design the optimal tablet for their specific pharmaceutical need. Therefore, our model is a necessary tool for the scientific world to develop cost and time efficient hydrogel drug-matrices.
hydrogel, drug delivery, modeling, transport, finite element method