Monitoring of drug release kinetics from thin polymer films by multi-parametric surface plasmon resonance.

The aim of the present study is to monitor the release of perphenazine (PPZ) from thin polymer films in real-time by the multi-parametric surface plasmon resonance method (MP-SPR). The MP-SPR method is capable of measuring changes in polymer films that are significantly thicker than the apparent scanning depth of the SPR field. The in vitro reference measurements confirm that the MP-SPR results can be correlated to the in vitro release of PPZ. However, information gained by MP-SPR can be used to identify three different modes of change in the films with different kinetic timescales, which are not visible in the in vitro testing. The EUDRAGIT(®) RL PO-PVP-PPZ-film shows significantly faster changes than the film without polyvinylpyrroline (PVP). This information can be used to optimize the drug-release profile of different film formulations for different pharmaceutical purposes.