Preparation and characterization of cytarabine-loaded w/o/w multiple emulsions

Abstract

Cytarabine-loaded w/o/w multiple emulsions were prepared using nonionic surfactants of the Tween and Span types, and characterized by studying the osmotic behavior. The effect of the sonication period on the entrapment efficiency, droplet size and emulsion stability was investigated. The entrapment efficiency was up to 79% and was not affected by the loading dose. The size of droplets decreased with increase in the second sonication time. It was found that the oil layer of multiple emulsion droplets including the hydrophobic fatty acid tails of surfactants behaves as a water-permeable membrane between two aqueous phases of w/o/w multiple emulsion. The combination of Tween 20/80 and Span 20/80 as a hydrophilic and lipophilic surfactant system produced the most stable multiple emulsion. The release study showed that the multiple emulsion containing cytarabine in the internal aqueous phase was stable, exhibiting a prolonged release pattern.