| Abstract: | Stealth multiple emulsions of small size, containing 6-mercaptopurine, were prepared by incorporation of sphingomyelins (SM) and monosialogangliosides (GM1) in the oily phase and by coating with lipid-grafted polyethylene glycol (PEG-PC). The three types of "stealth" multiple emulsions were characterized for size distribution, zeta potential, viscosity, encapsulation efficiency, drug release, and stability. Drug disposition studies were performed with formulated multiple emulsions to assess "stealth" behavior. The tissue distribution studies were carried out with the PEG grafted multiple emulsion. The results suggest that PEG-PC-coated multiple emulsions are superior as prolonged release and extended bloodcirculating carriers compared to multiple emulsions bearing either SM or GM1. |
