Abstract Purpose Inflammatory bowel disease (IBD) is a chronic inflammatory disorder requiring effective localized drug delivery to minimize systemic side effects. This study aimed to develop pH-responsive, Eudragit-based nanofiber formulations for colon-targeted oral delivery of hydrocortisone (HC). Methods HC-loaded nanofibers were fabricated using the electrospinning technique with Eudragit ® S100 and Eudragit ® L100-55 polymers. Physicochemical characterization was performed using Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), and Proton Nuclear Magnetic Resonance (¹H-NMR) analyses. Morphology, mechanical properties, contact angle, mucoadhesion, in vitro drug release, and ex vivo permeability were evaluated. Cytotoxicity and anti-inflammatory activity were assessed using RAW 264.7 macrophage cells. Results XRD and DSC analyses indicated a reduction in the crystalline nature of HC within the nanofiber matrix, suggesting partial amorphization following electrospinning. The optimized formulation (E4) exhibited uniform morphology, suitable mechanical properties, and enhanced mucoadhesion. In vitro release studies demonstrated minimal drug release under gastric conditions (~ 11% at pH 1.2) and increased release at intestinal and colonic pH, confirming pH-responsive behavior. Ex vivo studies showed comparable permeability among formulations. Cell culture studies revealed that the formulations were non-cytotoxic (> 80% cell viability) and and significantly reduced TNF-α expression by approximately 39% at the protein level and showed a comparable reduction at the mRNA level. Conclusion The developed Eudragit-based nanofiber system, particularly the E4 formulation, demonstrated effective colon-targeted delivery, favorable physicochemical properties, and significant anti-inflammatory activity. These findings indicate that HC-loaded nanofibers represent a promising platform for the localized treatment of IBD.
TUĞCU-DEMİRÖZ et al. (Sat,) studied this question.