Antitumour efficacy of cyclodextrin-complexed and niosome-encapsulated plumbagin in mice bearing melanoma B16F1

An inclusion complex of plumbagin with β-cyclodextrin was prepared with a view to increasing the aqueous solubility and stability of the drug. The drug complex and the free drug were entrapped in niosomes using a lipid layer hydration method with cholesterol, Span 60 and dicetyl phosphate. The niosomal entrapment efficiency of the drug complex was 74%, with the drug being incorporated into the aqueous layer of the vesicle. When administered subcutaneously to C57BL/6J mice bearing melanoma B16F1 at a dose of 5 mg kg^-1, the niosome entrapped drug complex had improved anticancer activity as evidenced by the enhanced volume doubling time and growth delay. Complexation with cyclodextrin increases the solubility and stability of plumbagin and also its efficacy. These effects were more pronounced when the complex was entrapped in the nonionic surfactant vesicles.