PREPARATION AND EVALUATION OF THE ANTIVIRAL ACTIVITY OF ACYCLOVIR LOADED NANO-NIOSOMES AGAINST HERPES SIMPLEX VIRUS TYPE 1

Acyclovir (ACV), analog of 2'-deoxyguanosine, is known for its antiviral activity against Herpes simplex virus (HSV). A major limitation of treatment with acyclovir is high distribution and low half-life that leads to taking high doses of acyclovir. Recent studies have shown that entrapment of acyclovir in nano-carriers can increase effectiveness and also decrease side effects of the drug. Therefore, in the present study the preparation and characterization of acyclovir loaded nanoniosomes was investigated. The non-ionic surfactant vesicles were prepared by thin film hydration method. The lipid composition in optimal formulation consisted of Span, cholesterol and D-. tocopheryl polyethylene glycol succinate (TPGS) in the molar ratio of 55 : 30 : 15, respectively. Physical characteristics of optimized niosomes such as particle size, encapsulation efficiency (EE) and in vitro drug release were evaluated. Furthermore, the in vitro cytotoxicity study of empty niosomes (E-N), acyclovir loaded niosomes (ACV-N) and ACV as a free drug against Hela cell line was performed by MTT assay. The average of particle size and EE for optimized niosomes were 122.6 +/- 0.2 nm and 24 % respectively. The drug release profiles proved the efficacy of optimized niosomes in prolonged release of ACV, so that the percent drug release for 1h was recorded as approximately 11.7 %. The prepared niosomes also showed significant stability with regard to particle size and EE when stored at least for seven days at 5 degrees C. The results of this study revealed ACV-N (F5) have a higher antiviral activity compared with free drug, and could be a suitable carrier for delivery of acyclovir in the treatment of HSV-1 infections.