Realgar nanoparticle‐based microcapsules: preparation and in‐vitro/in‐vivo characterizations

Objectives The aim of this study was to prepare microcapsules for the oral delivery of realgar nanoparticles ( RN ) that are also capable of improving its stability. Methods RN and RN ‐based microcapsules ( RNM ) were prepared using ball milling and solvent evaporation techniques, respectively. Properties such as particle size, ζ‐potential ( ZP ), morphology and X ‐ray diffractometer ( XRD ) were investigated. In addition, drug release, bioavailability and antitumour studies were also performed. Key findings The nanoparticles appeared round or elliptical in shape with a mean size of 85.4 ± 3.5 nm and a ZP of −34.3 ± 1.7  mV . The obtained RNM appeared spherical and not aggregated with a relatively narrow size distribution. XRD analysis revealed that ball milling technique did not change the crystallinity of the realgar powder. RN and RNM exhibited considerable higher release of As 2 S 2 , bioavailability and antitumour efficacies compared with crude realgar. Furthermore, RNM could protect RN directly exposed to the air and light, and therefore increased the stability of the RN . Conclusions The developed RNM demonstrated a greater potential as a delivery system for realgar.