Feasibility of Polymer/Drug Coating on Absorbable and Permanent Stent Platforms - Technological Challenges

Coating of drug-eluting stents demands different technologies depending on the nature of the stent platform, the intended coating design, and the coating materials. In this study, the complementary potentials of a spray-coating technology and a fluidized bed coating technology were assessed. Absorbable polymer stents and permanent metallic stents were coated with polymer/drug matrices based on poly(L-lactide) incorporated with the immunosuppressant sirolimus and the model substances fluorescein sodium, curcumin, and quinine. Process parameters were adjusted to yield optimal coating morphology. While spray-coating could be used to deposit even conversely asymmetric abluminal/luminal coating sandwiches, fluidized bed coating has shown tremendous throughput at a significant coating quality.