Preparation and evaluation of the self emulsifying drug delivery system containing loratadine

Self emulsifying drug delivery system (SEDDS) is an isotropic mixture of oil, surfactant and/or co-surfactant that improve the absorption of drugs in gastrointestinal tract and solve the solubility problems. The aim of this study was to formulate a SEDDS containing a lipophilic drug, loratadine, and to explore the potential of carriers for such system.For opportunity to perfect formulation, full factorial design with three variables; surfactant/oil, surfactant/co-surfactant proportion and percentage of drug in two levels were used. The effects of variables on formulation characters; emulsifying efficiency, particle size, drug release and rat intestine permeability were evaluated.The results showed liquid paraffin and labrafil as oil with span 20 as surfactant and capriol as co-surfactant prepared stable emulsions with refractive index higher than acidic medium and water. The particle sizes of formulations were influenced by type of oil, in the manner that liquid paraffin induced lower particle size in the range of 0.28- 1.8 micron. The percentage of drug release after 6 hrs for labrafil and liquid paraffin were 30.87-54.26% and 31.99-61.34 respectively. Formulations prepared with liquid paraffin and labrafil demonstrated drug permeability through rat intestine 2.72 and 2.25 folds compared to control. Comparison between drug release and in vitro permeability indicated that drug release from formulation after mixing with acidic condition is rate limiting for gastric absorption. In conclusion SEDDS prepared with liquid paraffin provided perfect solubility in acidic condition and increased intestinal permeability. Keywords: Loratadine- self emulsifying drug delivery systems- Oral drug delivery- Bioavailability