Chitosan coated layered clay montmorillonite nanocomposites modulate oral delivery of paclitaxel in colonic cancer

Paclitaxel (PTX), an antineoplastic bioactive, its clinical applications were hampered by its poor biopharmaceutical properties. There is need of safe, therapeutically effective and patient compliant drug delivery system. Clay minerals play a very crucial role in modulating drug delivery. The study deals with the investigation of a chitosan (CS) coated interlayer gallery of Na+ clay montmorillonite (MMT) and cationic paclitaxel (PTX) as a new drug delivery device to overcome PTX toxicity and enhance its therapeutic efficacy. PTX was intercalated into an interlayer gallery of MMT by an ion exchange reaction. Effect of different reaction conditions like time, pH and initial drug concentration on intercalation were studied. Optimised PTX-MMT hybrid nanocomposites were coated with biopolymer CS to get PTX-MMT-CS nanocomposites and characterised. Optimum intercalation (57·75%) of PTX molecules within the interlayer space of MMT was achieved with the pH of 6 at 3 h for 120 mg of PTX. The X-ray diffraction, Fourier transform infra red spectra and thermal analysis indicated the PTX intercalated into the clay interlayer space and stabilized in the longitudinal monolayer by electrostatic interaction. The surface morphology showed smooth layered surface. Nanocomposites demonstrated a controlled release of PTX and 1·2 fold improvement in vitro anticancer activities towards human colon cancer COLO-205 cells. This new nanocomposite material is a potential drug delivery system for oral administration of the anti-tumoral drug PTX, an alternative to the present intravenous administration.