Incorporation of Carvedilol into PAMAM-functionalized MWNTs as a sustained drug delivery system for enhanced dissolution and drug-loading capacity

The purpose of this study was to develop poly(amidoamine) (PAMAM)-functionalized multi-walled carbon nanotubes (MWNTs) loaded with a poorly water-soluble drug, intended to improve the drug-loading capacity, dissolution and design a sustained release system. MWNTs were modified with a carboxyl group by acid treatment and then complex with PAMAM. PAMAM-MWNTs were investigated as a scaffold for loading the model drug, Carvedilol (CAR), using three different methods (the fusion method, the incipient wetness impregnation method, and the solvent method). The effects of different pore size, specific surface area and physical state were systematically studied using FT-IR, TGA, SEM, DSC, nitrogen adsorption, XPS and XRD. All the samples made by PAMAM-MWNTs to load the drug had a marked effect on the drug-loading capacity as well as drug dissolution, especially the Ⅱ-30%.