Diffusion in Polymers and NMR

In order to produce more efficient controlled release systems, a better understanding of the diffusion process in polymer systems is essential. Diffusions studies have provided us with an enhanced comprehension of polymer morphology and of the phenomenon of mass transport, but there is still much more to investigate. Newer technique to study diffusion such as nuclear magnetic resonance (NMR) allows us to obtain information in a fast and simplest way, and allow us to address more complex questions and fine-tune the existing models of diffusion. In parallel to these studies, we have characterized the in situ diffusion in pharmaceutical tablets by NMR imaging techniques. The release of the drug from the tablet is related to the diffusion of these molecules, but also to the behavior of the tablet. NMR imaging allows us to characterize the penetration of water inside the tablets, tablet swelling, and tablet disintegration. NMR imaging could also be used for follow the mass transport of the drug in the tablets.