LIPOSOMES CONTAINING BORONOPHENYLALANINE FOR BORON NEUTRON-CAPTURE THERAPY

In the present work, liposomes loaded with Boronphenylalanine (BPA), w ith or without stabilization, were formulated for the application in b oron neutron capture therapy. BPA was encapsulated into liposomes as a complex with fructose, but also as a free drug in two different pH bu ffers. The influence of critical variables (cholesterol content, drug: lipid molar ratio, osmotic stress of liposomes containing hyperosmotic drug solution) on liposome morphology and drug content was evaluated. The drug content and dissolution profile of different BPA loaded lipo somes were also studied. The physical stability of liposomes in terms of changes in the size distribution in different osmotic pressure buff ers and the chemical oxidation of phospholipids during storing conditi ons were investigated. The encapsulation efficiencies of all formulati ons were always satisfactory, being between 20-48%; even when the lipo somes were exposed to high osmotic stress, the particle size was below 200 nm. The BPA-fructose complex loaded liposomes showed a slower dru g release profile.