The roles of a surfactant in zein-HPMC blend solid dispersions for improving drug delivery.

This study aimed to originally investigate the roles of a surfactant in hydrophilic-hydrophobic polymer blend solid dispersions (SDs) to enhance drug dissolution. Different formulations of SDs containing a hydrophilic polymer, a hydrophobic polymer or a hydrophilic-hydrophobic blend were prepared with/without surfactant, and the crystal changes, wettability, and molecular interactions were investigated. The wettability was investigated by analysing the contact angle. Powder X-ray diffraction (PXRD) and Fourier transform infrared (FTIR) spectroscopy were used to study the physicochemical properties of the SDs. This study showed that the surfactant improved the wettability of hydrophilic-hydrophobic blend SDs. Moreover, the incorporation of the surfactant led to the minimization of drug crystals in SDs. In particular, the surfactant showed an effectiveness in drug crystalline changes with hydrophobic polymers compared to hydrophilic polymers. The maximization of reducing drug crystals was observed in an optimized blending ratio of hydrophilic-hydrophobic polymers. This result indicated that the surfactant played a key role in assisting a hydrophilic-hydrophobic polymer blend, which has been demonstrated as a dominant strategy for SDs, to enhance the dissolution rate of a poorly water-soluble drug.