Summary
Delivering a drug to a specific part of the gut — rather than releasing it in the acidic stomach — calls for a coating that stays intact at low pH and opens further along the tract. This study uses coaxial electrospinning to build core/shell fibres with exactly that behaviour: a drug-loaded core of mucoadhesive poly(ethylene oxide) (PEO) surrounded by a shell of the pH-sensitive polymer Eudragit S100. Two model drugs were tested — acidic indomethacin and basic mebeverine hydrochloride — at several loadings (9–23% w/w of the core), with two PEO molecular weights explored for the latter. Electron microscopy confirmed distinct core and shell compartments and showed the drugs held in an amorphous state, while dissolution tests demonstrated the Eudragit shell strongly suppresses release under stomach-like acidic conditions — enabling site-specific, intestinal release.