The translation of underutilized botanical resources into advanced therapeutic dosage forms represents a critical frontier in pharmaceutical sciences. This study systematically characterizes the phytochemical and biological profiles of three Acanthus species (Acanthus ebracteatus, Acanthus ilicifolius, and Acanthus montanus) to develop a functional, rapid-release effervescent mouthwash tablet for oral mucosal repair. Phytochemical screening demonstrated that ethanolic extraction selectively concentrated bioactive phenolics and saponins compared to conventional aqueous methods. The ethanolic A. montanus extract emerged as the premier candidate, exhibiting the highest total phenolic content, excellent biocompatibility with human gingival fibroblasts, and significant promotion of in vitro cellular migration. Furthermore, it demonstrated robust, broad-spectrum antimicrobial efficacy against key cariogenic (Streptococcus mutans) and opportunistic (Candida albicans) oral pathogens. To transition this botanical discovery into a viable delivery system, the optimized extract was integrated into an effervescent base via wet granulation utilizing absolute ethanol, followed by blending with extragranular excipients and single-stroke compression. The resulting optimized matrix, incorporating 10% sodium starch glycolate, achieved an ideal mechanical-kinetic balance, yielding exceptional structural toughness (0.23% friability) and rapid disintegration (2.02 min). Advanced 3D synchrotron X-ray tomographic microscopy revealed that this specific super-disintegrant ratio generates a highly interconnected, porous internal architecture driving accelerated capillary-mediated breakdown. Ultimately, this study successfully translates a botanical extract into a mechanistically optimized, functionally validated dosage form for targeted oral therapies.