Development of a nanoparticles-in-microparticles system of poor water soluble drug—salmeterol xinafoate

Abstract

Objective: To prepare salmeterol xinafoate(SalX) loaded nanoparticles-in-microparticles system(SalX-NiMS).Methods: With chitosan being used as the carrier,a SalX-NiMS was prepared by ionotropic gelation technique combined with spray-drying method.Then,drug release property and dispersibility were investigated in vitro.Results: The prepared microparticles were spherical,with diameters ranging from 2-8 μm.The drug entrapment efficiency was(71.40±2.88)%,and the loading capacity was(7.67±0.31)%.The spray-dried microparticles displayed good fluidity with the bulk density being(217.28±1.47) mg/ml and the repose angle(30.24±0.77)°,respectively.It was apparent that the drug release profile of both original SalX and SalX-NiMS in vitro showed a rapid initial burst-effect(more than 50% of the drug was released within 2 h),more than 95% of drug could be released from the microparticles in 24 h.The SalX-NiMS released rather slowly compared to original SalX.The fine particle fraction value of SalX-NiMS was 22.07%.Conclusion: The sphere-shaped microparticles with satisfactory drug loading capacity and entrapment efficiency,controllable drug release in vitro and relatively high efficiency for respiratory inhalation were successfully prepared by using this method.Our research also laid a good foundation for further modification of the carrier.