Extended release of a novel antidepressant, venlafaxine, based on anionic polyamidoamine dendrimers and poly(ethylene glycol)-containing semi-interpenetrating networks

The multiple daily administration of venlafaxine, a novel third-generation antidepressant, was reduced based on polyamidoamine and polyethylene glycol (PEG)-containing semi-interpenetrating network (IPN), respectively. Venlafaxine was covalently linked to water-soluble G2.5 anionic polyamidoamine dendrimer via a hydrolyzable ester bond. Semi-IPN hydrogels were prepared by crosslinking acrylamide in the presence of PEG, and venlafaxine with predetermined amounts was loaded in situ. Dendrimer-venlafaxine conjugate and semi-IFNs were characterized by proton nuclear magnetic resonance and Fourier transform infrared, respectively. The effect of PEG concentration and molecular weight was studied and discussed for an optimal controlled release. (C) 2004 Wiley Periodicals, Inc.