ABSTRACT
Lipospheres are fat-based encapsulation system, developed for parenteral and topical drug delivery of bioactive compounds (1-12). Lipospheres consist of water dispersible solid microparticles, which have their diameter between 0.1 and 100 mm. These are composed of a solid hydrophobic fat core (triglycerides) stabilized by a layer of phospholipid molecules embedded in their surface. The internal core contains the bioactive compound, dissolved or dispersed in the solid fat matrix. The liposphere system has been used for the controlled delivery of various types of drugs including anti-inflammatory compounds, local anesthetics, antibiotics, and anticancer agents. They have also been successfully used as carriers of vaccines and adjuvants (2-5). Recently, lipospheres have been used for the delivery of peptides and for oral drug-delivery (10,11). Similar systems based on solid fats and phospholipids have been described (13,14). Solid lipid nanospheres, which are essentially nanosize lipospheres when phospholipid is used, have also been recently reviewed (14).
