Development and characterization of liquid and solid self-emulsifying drug delivery system of fexofenadine

Fexofenadine, the active metabolite of terfenadine, a well known and effective H1 receptor antagonist, is administered by the oral route. The objective of present investigation was to develop and characterize a liquid self-emulsifying drug delivery system (SEDDS) and a solid SEDDS by using bioenhancer excipients like Tween 80 and Labrasol which are known for their inhibiting action on CYP450 and P-glycoprotein pump. Solubility of fexofenadine was determined in various vehicles, including oils, surfactants and co-solvents. Various evaluation parameters (emulsification study, particle size, poly-dispersibility index, % drug release, etc.) were carried out to find out optimized liquid SEDDS formulation. Optimized liquid formulations were converted in solid SEDDS by simple and convenient physical adsorption technique. Solid SEDDS was characterized by X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and Fourier transport infra-red spectroscopy. The optimized liquid SEDDS formulation contained 29 % Captex 200P/Capmul MCM C8 EP as oil, 47 % Labrasol/Tween 80 as a surfactant and 24 % Ethanol as a co-solvent. The optimized liquid and solid SEDDS showed higher drug release than pure API powder. DSC and XRD results of solid SEDDS confirmed that the drug presented in the formulation was in an amorphous state. The prepared liquid SEDDS and solid SEDDS containing bio-enhancer excipients increased the in vitro dissolution rate of fexofenadine compared to pure drug and has potential to increase bioavailability by blocking Pgp efflux pump and CYP450 hepatic metabolism. © 2013 The Korean Society of Pharmaceutical Sciences and Technology.