Formulation optimization and in vitro characterization of rifampicin and ceftriaxone dual drug loaded niosomes with high energy probe sonication technique

The aim of the present study was to prepare niosomal formulations for dual drug therapy of ceftriaxone sodium and poorly water-soluble rifampicin by the ecological probe sonication method. Pluronic L121 and Span 60 were used as surface active agents and the optimization of the composition was made with the aid of Design of Experiment (DoE) concept. Concentration levels of charge inducing agent, dicetylphosphate (DCP), and Pluronic L121 were studied as variables. Prepared niosomes with varying concentrations of DCP and Pluronic L121 resulted in small sized niosomes with sizes ranging from 165 nm to 893 nm. During the four weeks stability testing, the particle sizes of the empty niosomes were reduced, while the particle sizes of the drug loaded niosomes were increased very slightly. The optimized formulations resulted in stable niosomes with high drug entrapment efficiencies: entrapment efficiency was 99% for rifampicin and 96% for ceftriaxone. All the niosomal formulations showed faster in vitro drug release rates as compared to bulk drug formulations. In conclusion, ceftriaxone and rifampicin loaded niosomes prepared with Pluronic L121 and Span 60 resulted in stable, small sized niosomes with high drug entrapment efficiencies and improved drug release profiles.