Liposomes are used clinically in the delivery of anti-cancer and antifungal drugs.

(a) What are liposomes? Describe their structural properties with the aid of a diagram. (4 marks)

(b) Explain how liposomes are used in drug delivery. Discuss their advantages and disadvantages.(5 marks)

(c) Conventional liposomes are prone to reticuloendothelial clearance following intravenous administration. Explain the term ‘reticuloendothelial clearance’ and explain how this can be overcome.(4 marks)

(d) Name one marketed product that uses liposomes and state its indication.(2 marks)