Nanoemulsion Formulations for Improved Oral Delivery of Poorly Soluble Drugs
S.B. Tiwari, D.B. Shenoy and M.M. Amiji
Norheastern University, US
nanoemulsion, hydrophobic drugs, oral bioavailability
Purpose: To develop nanoemulsion formulations to enhance oral bioavailability of hydrophobic drugs. Paclitaxel was selected as a model hydrophobic drug. Methods: The oil-in-water (o/w) nanoemulsions were made with pine nut oil as the internal oil phase, egg lecithin as the primary emulsifier, and water as the external phase. Stearylamine and deoxycholic acid were used to impart positive and negative charge to the emulsions, respectively. Nanoemulsions were prepared by sonication method and characterized for particle size and surface charge. Nanoemulsion formulations with tritiated [3H]-paclitaxel were administered orally to C57BL/6 mice and the distribution of the drug was examined.
Results: The formulated nanoemulsions had a particle size range of 90-120 nm and zeta potential ranging from +34 mV to -45 mV. Following oral administration, a significantly higher concentration of paclitaxel was observed in the systemic circulation when administered in the nanoemulsion relative to control aqueous solution. The absorbed drug was found to be predominantly distributed in the liver, kidneys, and lungs.
Conclusions: Formulations of nanoemulsions were shown to generate enhancement in the oral bioavailability of paclitaxel, a model hydrophobic drug, relative to administration in aqueous solution. The results of this study suggest that nanoemulsions are promising novel formulations that can enhance the oral bioavailability of hydrophobic drugs.
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Nanotech 2006 Conference Program Abstract