In vitro biological activity of resveratrol using a novel inhalable resveratrol spray-dried formulation.

The aim of the study was to prepare inhalable resveratrol by spray drying for the treatment of chronic obstructive pulmonary disease (COPD). Resveratrol, with a spherical morphology and particle diameter less than 5 μm, was successfully manufactured. Fine particle fraction (FPF) and mass median aerodynamic diameter (MMAD) of spray-dried resveratrol was 39.9 ± 1.1% and 3.7 ± 0.1 μm, respectively when assessed with an Andersen cascade impactor (ACI) at 60 l/min. The cytotoxicity results of spray-dried resveratrol on Calu-3 revealed that the cells could tolerate high concentration of resveratrol (up to 160 μM). In addition, in transport experiments using Snapwells, it was observed that more than 80% of the deposited dry powder was transported across the Calu-3 cells to the basal chamber within four hours. The expression of Interleukin-8 (IL-8) from Calu-3 induced with tumor necrosis factor alpha (TNF-α), transforming growth factor beta (TGF-β1) and lipopolysaccharide (LPS) were significantly reduced after treatment with spray-dried resveratrol. The antioxidant assay (radical scavenging activity and nitric oxide production) showed spray-dried resveratrol to possess an equivalent antioxidant property as compared to vitamin C. Results presented in this investigation suggested that resveratrol could potentially be developed as a dry powder for inhalation for the treatment of inflammatory lung diseases like COPD.