The work herein presented aims to develop and characterize carvedilol (CVD) releasable non-water-soluble monolayers and a multilayer patch made of ultrathin micron and submicron fibers for drug delivery into the sublingual mucosa. Firstly, the developed formulations containing CVD within different biopolymers (PDLA, PCL, and PHB) were characterized by scanning electron microscopy (SEM), attenuated total reflectance Fourier transformed infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC), wide-angle X-ray scattering (WAXS), and for their in vitro drug release. SEM micrographs assessed the fiber morphology attained by adding carvedilol. ATR-FTIR spectra revealed good chemical compatibility between CVD and the tested biopolymers, whereas DSC and WAXS confirmed that CVD was in an amorphous state within the biopolymeric fibers. In vitro release studies showed enhanced CVD release kinetics from the electrospun biopolymer monolayers compared to the dissolution rate of the commercial form of the pure drug, except for the slow-releasing PDLA fibers. Finally, the selected CVD-loaded layer, i.e., electrospun PHB, was built into a three-layer patch to tackle mucosa adhesion and unidirectional release, while retaining the enhanced release kinetics. The patch design proposed here further demonstrates the potential of the electro-hydrodynamic processing technology to render unique mucoadhesive controlled delivery platforms for poorly water-soluble drugs.
Keywords: carvedilol; electrospinning; mucoadhesive delivery platform; nanofibers; solid amorphous dispersions.