Ruggero Bettini

TL;DR: Gel-layer behaviour, front movement and release are described to show the dependence of the release kinetics on the swelling behaviour of the system and in vivo behaviour of matrix systems.

TL;DR: The movement of the penetrant and polymer fronts and the drug dissolution in highly loaded swellable matrix tablets showed that the difference between the diffusion and erosion fronts is decisive for the release kinetics, leading to a new finding that the distance between diffusion and eroded fronts is the most important parameter for drug release.

TL;DR: The results showed that the rate and amount of drug released from swellable matrices was dependent not only from drug dissolution and diffusion but also from solid drug translocation in the gel due to polymer swelling.

TL;DR: It was shown that as drug solubility increased, the undissolved drug gel layer thickness decreased, again showing the importance of the movement of the diffusion front in controlling the overall release.

TL;DR: The physical analysis of swellable hydroxypropyl methyl cellulose matrices loaded with increasing amounts of soluble and colored drug and exhibiting swelling, diffusion and erosion fronts clearly showed the importance of drug solubility and loading in the observation of the diffusion front.