Core-matched encapsulation of an oleate prodrug into nanostructured lipid carriers with high drug loading capability to facilitate the oral delivery of docetaxel

Nanostructured lipid carriers (NLC) have been considered as promising vehicles for oral delivery of taxanes, such as docetaxel (DTX). However, the low drug loading capability (∼5%, w/w) has greatly limited their clinical application. In response to this challenge, a novel lipophilic oleate prodrug of DTX (DTX-OA) was synthesized and efficiently encapsulated in NLC using core-match technology, in which liquid lipid (OA) was used as core matrix to enhance compatibility with DTX-OA. DTX-OA-NLC showed uniform particle size of about 100   nm with markedly high drug loading capability (∼23% of DTX, w/w) compared with DTX-NLC (∼5%, w/w). Besides, DTX-OA-NLC showed better colloidal stability and slower drug release property compared with DTX-NLC. The prepared NLC could be accumulated more easily in MDCK cells than drug solution, and clathrin-mediated endocytosis was the main endocytosis pathway. In situ single-pass intestinal perfusion (SPIP) and intestinal biodistribution studies demonstrated the improved membrane permeability and intestinal wall bioadhesion of NLCs. The bioavailability of DTX-OA-NLC showed 4.04-fold and 2.06-fold higher than DTX solution and DTX-NLC, respectively. These results suggest that the core-matched prodrug-NLC is a promising platform to facilitate the oral delivery of DTX.