Everolimus-encapsulation in Pluronic P123 self-assembled micelles as drug delivery systems for drug-coated balloons

Abstract

Drug-coated balloons (DCBs) are effective tools for cardiovascular interventions, ensuring uniform drug delivery to occluded arteries. This research investigates the potential of Pluronic P123 (P123), a micelle-forming polymer, to solubilize and release Everolimus (EVE) from DCBs. Furthermore, it seeks to understand how the ratio of P123 to EVE affects release rates and micelle formation under physiological conditions. We tested three P123 to EVE ratios: 90:10, 75:25, and 50:50. Microscopy revealed that increasing EVE proportions resulted in more uniform coatings. Fourier-transform infrared spectroscopy (FTIR) analysis confirmed the successful incorporation of EVE into the P123 matrix without altering its chemical properties. Differential scanning calorimetry (DSC) studies showed that EVE incorporation affected the crystalline structure of P123, leading to more uniform coatings. In vitro release studies showed that all formulations had <1% drug loss in the first minute (the tracking phase); furthermore, the 90:10 ratio exhibited optimal drug release in the following 3 min, corresponding to the deployment phase in DCB angioplasty. Analysis of micelle loading capacity (LC), encapsulation efficiency (EE), size, and structure indicated an increase in both LC and EE with higher EVE content and a corresponding enlargement in micelle size. Given these findings, the optimized formula provided a consistent coating on commercial balloons, highlighting the potential of using P123 for DCB drug coating and release.