Uptake capacity and adsorption isotherms of doxorubicin on polymeric nanoparticles: effect of methods of preparation

Abstract

Nanoparticles made from biodegradable materials like polyalkylcyanoacrylates are being examined as drug delivery systems. The capacity of these particles to carry a drug can differ subject to the method of manufacture. We studied the adsorption and uptake of doxorubicin by nanoparticles when the drug was added before or after completion of formation of the isobutylcyanoacrylate nanoparticles. The uptake of the drug was measured by ultracentrifugation. The percent of the drug associated with the nanoparticles formed in the presence of the drug was twice that of the other method. However, the affinity of doxorubicin for nanoparticles of either method, determined by the Langmuir and Freundlich isotherms, was the same. The release study indicated that only 4 to 8% of the drug is released in vitro under sink condition. This may suggest that the drug adsorbs strongly on the surface and also associates with the matrix of the nanoparticles.