Preparation and in vitro evaluation of the antiviral activity of the Acyclovir complex of a β-cyclodextrin/poly(amidoamine) copolymer

A poly(amidoamine) (PAA) copolymer with β-cyclodextrin was obtained by polyaddition reaction of 6-deoxy-6-amino-β-cyclodextrin (β-CD-NH2) and 2-methylpiperazine to 2,2-bis(acrylamido)acetic acid in aqueous medium. This β-CD/PAA copolymer bears β-CD units along the macromolecular chain, is water-soluble and non-cytotoxic. The complexing capacity of β-CD/PAA was determined using an antiviral drug, Acyclovir, as a model of poorly water-soluble drug. Complex formation was confirmed by means of DSC and FTIR analyses. β-CD/PAA can solubilize up to 11% w/w of Acyclovir notably increasing the aqueous solubility of the drug. The in vitro release studies showed the dependence of Acyclovir release rate on the solution pH. The antiviral activity of Acyclovir β-CD/PAA complex was evaluated against herpes simplex virus type I in cell cultures. The Acyclovir β-CD/PAA complex exhibited a higher antiviral activity than the free drug.