Surface Wettability Modulated by Surfactant and Its Effects on the Drug Release and Absorption of Fenofibrate Solid Dispersions.

The objective of this study is to explore the surface wettability modulated by a surfactant and its effects on the drug release and absorption of fenofibrate solid dispersions (FF SDs). Both the polyvinylpyrrolidone/sodium lauryl sulfate (PVP/SLS) coprecipitate and FF SDs were prepared by solvent evaporation method. The contact angle of PVP/SLS coprecipitate with various PVP/SLS weight ratios was determined to screen out the suitable content of SLS incorporated in FF SDs. Scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) was used to analyze the surface composition of the PVP/SLS coprecipitate, suggesting that SLS molecules were prone to concentrate on the carrier surface. The physicochemical characteristics of FF, PVP, SLS, FF SDs, and FF physical mixtures (PMs) were evaluated by thermal analysis, XRD, FTIR, and SEM, which revealed that FF was molecularly dispersed in SDs. The interaction between SLS and PVP or FF confirmed by FTIR would affect the surface morphology of SDs. Finally, the contact angle of FF SDs was measured to explore the effects of surface wettability on the dissolution behavior and drug absorption of FF SDs. The interesting thing is that the wettability of the PVP/SLS coprecipitate was positively related to that of FF SDs. The improved wettability of FF SDs or the PVP/SLS coprecipitate by adding SLS contributed to the slight enhancement of initial drug release and absorption, which implied that wettability would be a promising tool in the formulation studies.