Carbon Nanotube: A Novel Carrier for Sustained Release Formulation

Abstract

The present work describes the physicochemical interaction of multi-walled carbon nanotubes (MWCNTs) with drugs differing in physicochemical properties and shows the potential of MWCNTs in extended release dosage form design. The drug-nanotube adsorbate of candesartan cilexetil (CC), diclofenac sodium (DS) and diltiazem hydrochloride (DH) was prepared by nanoprecipitation technique. Adsorbates were evaluated for drug content, drug release mechanism and physicochemical interaction using scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), powder X-ray diffractometry (PXRD) and dissolution study. The effect of carbon nanotube on the drug release profile was investigated. The prepared adsorbates exhibited satisfactory physico-chemical characteristics. The spectral studies shows only physical interaction between all drug molecules and MWCNTs. Hydrophobic drug shows stronger interaction with MWCNTs. Both the nanoscale diameter of MWCNTs and hydrophobicity of the drug affected the rate of release. The most hydrophobic drug candesartan cilexetil shows extended drug release of only 20% in 15 hours; highly water soluble drug diltiazem hydrochloride shows 90% release in 15 hours. MWCNTs thus promise considerable utility in the development of extended release drug delivery systems.