A novel doxorubicin-loaded in situ forming gel based high concentration of phospholipid for intratumoral drug delivery.

The purpose of this study was to develop a safe and effective drug delivery system for local chemotherapy. A novel injectable in-situ-forming gel system was prepared using small molecule materials, including phospholipids, medium chain triglycerides (MCTs), and ethanol. Thus, this new sustained release system was named PME (first letter of phospholipids, MCT, and ethanol). PME has a well-defined molecule structure, a high degree of safety, and better biocompatible characteristics. It was in sol state with low viscosity in vitro and turned into a solid or semisolid gel in situ after injection. When loaded with doxorubicin (Dox), PME-D (doxorubicin-loaded PME) exhibited notably antitumor efficiency in S180 sarcoma tumors bearing mice after a single intratumoral injection. In vitro, PME-D had remarkable antiproliferative efficacies against MCF-7 breast cancer cells for over 5 days. Moreover, the initial burst effect can hardly be observed from PME system, which was different from many other in-situ-forming g...