Preparation of liposomes containing factor VIII for oral treatment of haemophilia.

Different types of liposomes composed of a variety of lipids have been compared for their ability to incorporate Factor VIII, with a view to attempting oral therapy of haemophilia. Reverse evaporation liposomes (REV) composed of unsaturated phospholipids, allowed adequate levels of entrapment for administration to haemophilic dogs, but failed to promote entry of Factor VIII into the vasculature, possibly due to liposome breakdown and denaturation of Factor VIII within the gastrointestinal tract. A novel technique was therefore developed which made possible high-yield entrapment of Factor VIII in much more stable liposomes based on the saturated phospholipid, distearoyl phosphatidylcholine. This new technique has a number of other important features which make it an attractive method for the incorporation of a wide range of materials into liposomes.