The enhancing effect of N-acetylcysteine modified hyaluronic acid-octadecylamine micelles on the oral absorption of paclitaxel.

A micelle system based on hyaluronic acid (HA)-octadecylamine (OA) conjugate (HOA) functionalized with N-acetylcysteine (NAC) was constructed to yield NAC modified HOA conjugate (NHOA) for improving oral paclitaxel (PTX) delivery (PTX-NHOA). The average size of spherical PTX-NHOA micelles was 162.7 nm with a zeta potential of -27.6 mv. The encapsulation efficiency (EE) and drug loading (DL) of PTX-NHOA micelles were 92.64% and 6.96%, respectively. Additionally, NHOA micelles exihibited significantly higher cellular uptake in comparison with HOA micelles by caveolin-mediated and clathrin-mediated endocytosis. Higher permeation ability of NHOA micelles (2.75-fold and 1.32-fold, respectively) through cell monolayers of Caco-2/HT29 cells than that of Taxol and HOA micelles were also observed. The intestinal biodistribution result showed that NAC-modified micelles could enhance its adhesion to the intestinal surface and permeate deeply within the intestinal villi. The NHOA micelles were better absorbed in the duodenum, followed by the jejunum and the ileum. In vivo pharmacokinetic studies showed that AUC0-t value of PTX-NHOA micelles was about 5.92-fold and 2.47-fold higher compared to that of Taxol and PTX-HOA micelles, respectively. In a word, NHOA micelles is a promising drug delivery system in improving the oral absorption of insoluble drugs.