antimicrobial activity of liposome encapsulated cycloltyrosyllprolyl various studies have shown the potentially beneficial biological activities of cyclic dipeptides and in particular cycloltyrosyllprolyl cyclotyrpro has shown fair antibacterial activity in vitro this study aimed to determine if liposome encapsulation would have any significant effects on the antibacterial activity of this compound the thinfilm hydration method with extrusion was used to produce small unilamellar vesicles containing cyclotyrpro that were shown to have an average encapsulation of 94 with a mean particle size of 1604 nm minimum inhibitory concentrations tested against staphylococcus aureus escherichia coli klebsiella pneumoniae and bacillus subtillis were shown to be lower in liposome encapsulated cyclotyrpro than for the free form while no antimicrobial activity was noted for either encapsulated nor nonencapsulated drug against the fungus candida albicans or two methicillinresistant strains of staphylococcus aureus mrsa a positive control of liposome encapsulated amoxicillin was shown to be extremely active against both mrsa strains the results confirm that liposome encapsulation has the potential to enhance activity as well as to overcome bacterial resistance towards current antibacterial agents