Controlled Release Ultrasonic-Coated Drug-Eluting Stent with Multilayers of Chitosan and Curcumin

In clinical practice, several commercial drug-eluting stent products have limitations during the early drug-release phase due to the phenomenon of initial burst release (IBR), which may increase the risk of restenosis. This experimental study utilized a multilayer strategy with genipin-crosslinked chitosan as the polymer and curcumin as the drug to address these limitations.

Based on the forward speed of the rotary drive (7, 8, and 9 mm/s), ultrasonic coating was used to create uniform layers, followed by scanning electron microscopy (SEM) and a release study. Validation of the analytical method confirmed the reliability of the UV-Vis spectrophotometric technique.

The release data modeled with the Korsmeyer-Peppas model show Super Case II transport via relaxation/erosion. The Peppas-Sahlin model indicates that Fickian diffusion dominated the first 6-7 days, after which polymer relaxation became dominant. At 9 mm/s, Fickian diffusion persisted for up to seven days, whereas at 7 and 8 mm/s, it was limited to the first six days.

The multilayer system maintains matrix integrity during drug release, preventing initial burst release. Once the mechanism shifts from diffusion to relaxation, no burst is observed. The zero-order model fit confirms that the design reflects a controlled-release profile.

The strategy demonstrates controlled release without initial burst.