Alpha-mangostin (AMG) is a natural compound possessing strong antibacterial activity. Because of its poor water solubility, the formulations of AMG usually require high concentrations of solubilizers leading limitation for using in some clinical applications. Thus, the novel formulation of topical nanoemulsion (NE) containing AMG (AMG-NE) with optimal content of the oil phase and surfactants was developed. AMG was extracted, purified and used as an active ingredient of AMG-NE. Blank NEs (NEs without AMG) with varying in contents of the oil phase and surfactants and AMG-NE were prepared by the ultrasonication technique. They were investigated their physicochemical properties including antibacterial activity against Staphyloccocus aureus and Propionibacterium acnes (which is recently renamed as Cutibacterium acnes). Blank NEs and AMG-NE had droplet size in a range of nanometer and negative value of zeta potential. The droplet size, polydispersity index and zeta potential of blank NEs were affected by formulation compositions and sonication intensities. AMG could be loaded into a representative Blank NE at a maximum concentration of 0.2% w/w and did not cause significant changes in physicochemical properties. AMG-NE showed the antibacterial activity against Staphyloccocus aureus and Propionibacterium acnes without toxicity to the skin cells. Therefore, AMG-NE had potential for using in a clinical study to investigate its efficacy and safety in patients.

This study aimed to develop a chemically stable niosomal eye drop containing fosinopril (FOS) for lowering intraocular pressure. The effects of cyclodextrin (CD), surfactant types and membrane stabilizer/charged inducers on physiochemical and chemical properties of niosome were evaluated. The pH value, average particle size, size distribution and zeta potentials were within the acceptable range. All niosomal formulations were shown to be slightly hypertonic with low viscosity. Span^® 60/dicetyl phosphate niosomes in the presence and absence of γCD were selected as the optimum formulations according to their high %entrapment efficiency and negative zeta potential values as well as controlled release profile. According to ex vivo permeation study, the obtained lowest flux and apparent permeability coefficient values confirmed that FOS/γCD complex was encapsulated within the inner aqueous core of niosome and could be able to protect FOS from its hydrolytic degradation. The in vitro cytotoxicity revealed that niosome entrapped FOS or FOS/γCD formulations were moderate irritation to the eyes. Furthermore, FOS-loaded niosomal preparations exhibited good physical and chemical stabilities especially of those in the presence of γCD, for at least three months under the storage condition of 2–8 °C.