Formulation and Evaluation of Zidovudine Loaded Niosomes
In the past few decades, considerable attention has been focused on the development of new drug delivery system (NDDS). The NDDS should ideally fulfill two prerequisites. Firstly, it should deliver the drug at a rate directed by the needs of the body, over the period of treatment. Secondly, it should channel the active entity to the site of action. Now a days vesicular drug delivery system plays an important role as it is targeting type of drug delivery system which includes liposomes ,niosomes pharmacosomes and virosomes. Vesicular drug delivery systems delay drug elimination of rapidly metabolizable drugs, and function as sustained release systems. Niosomes are multilamellar or unilamellar vesicles wherein an aqueous solution of solute(s) is enclosed in highly ordered bilayer made up of non-ionic surfactant with or without cholesterol and dicetyl phosphate and exhibit behavior similar to liposomes. Niosomes of Zidovudine were prepared by ether injection method by varying ratios of span 80 and span 20 with cholesterol in ratio of 1:1,2:1and 3:1.and dicetyl phosphate added to the formulation to prevent aggregation of vesicles .the prepared vesicles were characterized for their size ,entrapment efficiency leakage studies ,osmotic shock and invitro drug release profile and the niosomes were characterized by their entrapment efficiency and invitro release profile and the niosomes with span and cholesterol in ratio of 2:1 had high drug release profile were found to be best formulations and they increase the therapeutic effectiveness of Zidovudine and prolong the therapeutic action of drug.