A Lipid-Based In Situ-Forming Hexagonal Phase for Prolonged Retention and Drug Release in the Breast Tissue.

In this study, the addition of monoolein to phosphatidylcholine (PC), tricaprylin, and propylene glycol (PG) mixtures was studied to produce fluid precursor formulations (FIPs) that could transform into hexagonal phase (resistant to aqueous dilution) in vitro and in vivo. The overall goal was to obtain FIPs that could incorporate chemopreventive drugs for subcutaneous administration in the mammary tissue to inhibit the development and/or recurrence of breast cancer. Increasing PG content reduced FIP viscosity up to ~ 2.

Microemulsion for Prolonged Release of Fenretinide in the Mammary Tissue and Prevention of Breast Cancer Development.

The need of pharmacological strategies to preclude breast cancer development motivated us to develop a non-aqueous microemulsion (ME) capable of forming a depot after administration in the mammary tissue and uptake of interstitial fluids for prolonged release of the retinoid fenretinide. The selected ME was composed of phosphatidylcholine/tricaprylin/propylene glycol (45:5:50, w/w/w) and presented a droplet diameter of 175.3 ± 8.