Microencapsulation of nanoparticles with enhanced drug loading for pH‐sensitive oral drug delivery for the treatment of colon cancer

Abstract

Abstract Drug‐delivery carriers must endure harsh pH conditions in the gastrointestinal tract and still maintain a high drug loading (DL) for oral therapeutic drugs to be effectively delivered to the colon area. In this research, a pH‐sensitive drug‐delivery system with an enhanced DL was developed by the coating of 5‐fluorouracil (5‐FU)‐loaded poly(lactide‐ co ‐glycolide) (PLGA) nanoparticles (NPs) with Eudragit S100 with an oil‐in‐oil solvent evaporation technique. The enhanced DL and encapsulation efficiency were achieved by the optimization of the fabrication parameters and by the use of particles of a proper size. A DL of 5.8% was obtained by a moderate initial drug feeding, a high volume ratio of the outer water phase to the organic phase, and by the adjustment of the pH value of the outer aqueous phase to the isoelectric point of 5‐FU. An in vitro drug‐dissolution test showed that the coating of the Eudragit S100 microspheres could effectively prevent drugs from being released in an environment with a pH lower than 7. The PLGA NPs showed an initial burst release followed by a slow and sustained release over an extended period of over 120 h at pH value of 7.4. Therefore, the prepared systems have great potential for practical applications in the treatment of colorectal cancer. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013