Comparative Study of Ibuprofen and Indomethacin Loaded Poly(caprolactone) Nanoparticles : Physicochemical Properties

Nanotechnology is a straightforward strategy for the development of drug delivery systems. Poly(caprolactone) (PCL) has been used as a hydrophobic biodegradable polymeric core of nanoparticles for encapsulation of various kinds of self-problematic drugs. In this study, PCL was fabricated by ring opening polymerization and the nanoparticles were then obtained by solvent diffusion and evaporation method using Tween 80 and Span 80 as surfactants and Poloxamer 188 as a stabilizer. Ibuprofen and indomethacin were encapsulated into the PCL nanoparticles to observe the effect of molecular characteristics on the physicochemical properties of the nanoparticles. The results showed that the characteristics of encapsulated drugs profoundly affected the physicochemical properties of the nanoparticles. After incorporation of drug, indomethacin provided smaller particle size, less size distribution, and more negative surface charge as compared to ibuprofen, probably due to the individual effect on the polymer and surfactant during nanoprecipitation. Also, %yield, %entrapment efficiency and %drug loading of indomethacin-loaded nanoparticles were higher than those of ibuprofen-loaded nanoparticles at all drug:polymer ratios. The result indicated that the hydrophilic small molecular drug, ibuprofen, was less efficiently entrapped in the system than the hydrophobic larger molecular drug, indomethacin, due to the drug leakage during incorporation process by nanoprecipitation method. Thus, it can be concluded that the different physicochemical properties of drug profoundly have individual effect on the drug-loaded PCL nanoparticles.