Cyclodextrin/PVP-Based Nanofibers with Rhadiola rosea Extract as a New System for Increasing Bioavailability of Active Components

The present study aimed to optimize the extraction process for Rhodiola rosea root, then develop and optimize electrospun nanofiber systems containing extract to enhance the bioavailability of its active compounds, salidroside and rosarin. Using a Design of Experiments (DoE) approach, nanofibers were prepared with varying ratios of polyvinylpyrrolidone (PVP) and hydroxypropyl-cyclodextrins (HPαCD, HPβCD, HPγCD). The systems were comprehensively characterized in terms of morphology, content of active compounds, dissolution rate, permeability, mucoadhesion, antioxidant, and anti-inflammatory activities. The results showed that nanofiber formulations significantly improved the dissolution and permeability of salidroside and rosarin compared to the crude extract. The antioxidant properties were notably enhanced, while the anti-inflammatory activity varied depending on composition. The formulation containing 3 g HPβCD and 2.5 g PVP demonstrated the most favorable balance of functional and technological properties. Principal Component Analysis (PCA) and correlation matrix analysis confirmed that system composition strongly influenced the interrelationships between technological parameters and bioactivity. These findings indicate that electrospun nanofibers based on cyclodextrin-PVP matrices are a promising preclinical strategy for improving the delivery of Rhodiola rosea bioactives.