Drug delivery, development, and technological aspects for peripheral drug eluting stents

Drug-eluting stents are the standard therapy for arterial occlusions, particularly in peripheral arterial disease, owing to their efficacy in mitigating in-stent restenosis, maintaining favorable biocompatibility, and improving patient compliance. Their performance can be enhanced through the integration of particulate systems, cytostatic agents, and biodegradable polymers. The complexities associated with chronic disease progression, recurrent in-stent restenosis, the impracticality of long-term animal studies, and the absence of United States Food and Drug Administration-endorsed in vitro drug release protocols for peripheral drug-eluting stents underscore the need for modified strategies and accelerated in vitro release testing as a quality control strategy. In addition to in vitro drug release, other critical evaluation parameters for coated stents include coating uniformity, thickness, drug content, biodegradability, particulate matter, and sterility testing. Ethylene oxide is the most widely used method for the sterilization of drug-eluting stents. Despite their clinical significance, standardized regulatory guidelines and a unified scientific framework for stability testing remain limited. This review provides a comprehensive overview of drug delivery strategies for peripheral drug-eluting stents, coating methodologies, evaluation criteria, in vitro drug release and permeation studies, preclinical animal models, drug release correlations, and stability considerations, along with perspectives on future advancements and opportunities in this field.