Advancements in buccal drug delivery: a mechanistic review of fast-disintegrating electrospun nanofiber mats.

Buccal drug delivery enables rapid absorption by bypassing gastrointestinal degradation and hepatic first-pass metabolism. However, conventional films, tablets, and patches suffer from slow hydration and salivary washout, which often delay drug absorption before it can permeate the mucosa. Fast-dissolving (FD) electrospun nanofiber mats overcome these limitations. These mats disintegrate in under 30 s and release ≥80-90% of the loaded drug within ∼60 s, driven by their nanoscale fibers (100-900 nm), their enormous surface area, their high porosity, and the formation of amorphous solid dispersions during rapid solvent evaporation. The article reviews material selection (hydrophilic polymers such as polyvinylpolypyrrolidone, poly(vinyl alcohol), and pullulan), electrospinning parameters, and architectural variations (blend, coaxial, and multilayer) that enable instantaneous capillary-driven wetting, volumetric hydration, and erosion-mediated burst release. Mechanistic insights are supported by Fick's first law, demonstrating that transient supersaturation and reduced diffusion path lengths generate 2- to 3-fold higher early-phase mucosal flux than in conventional systems. Comprehensive characterization approaches, representative drug examples, and practical barriers to translation have also been highlighted in this review. Fast-dissolving nanofiber mats address key limitations of buccal drug delivery, particularly the challenge of rapid onset. Remaining challenges in scalability, reproducibility, and regulatory standardization can be addressed by developing better in vitro and in vivo models and by drawing early clinical conclusions.