ABSTRACT

Acyclovir, a synthetic purine nucleoside analogue derived from guanine, is clinically used in the treatment of herpes simplex viruses (HSV), varicella-zoster virus, Epstein-Barr virus, and cytomegalovirus (1). The low water solubility (about 0.2% at 25°C) of acyclovir imposes limitations to its therapeutic application (2, 3). Therefore, it is important to use alternative approaches to increase the bioavailability of the drug. Cyclodextrins are well known for their ability to increase the dissolution of lipophilic drugs by formation of inclusion complexes (4, 5). Polyethylene glycols have also been reported to increase the solubility of various lipophilic drugs as a carrier of the drugs to the aqueous system (6–8).