Investigation of Hexadecylphosphocholine (miltefosine) usage in Pegylated liposomal doxorubicin as a synergistic ingredient: In vitro and in vivo evaluation in mice bearing C26 colon carcinoma and B16F0 melanoma.

In this investigation, Hexadecylphosphocholine (HePC, miltefosine) was being used as a new ingredient in Pegylated liposomal doxorubicin (PLD) and different aspects of this integration such as its effect on doxorubicin (Dox) release and cell uptake, cytotoxicity of liposomes, in vivo distribution and half-life clearance time of Dox as well as median survival time were illustrated. The liposomal formulations were Pegylated liposomal doxorubicin containing 0, 0.5, 1, 2 and 4% mole ratios of HePC (HePC-PLD) and their respective Dox-free liposomes (HePC-PLs). The cells used were colon carcinoma (C26), adriamycin-resistant breast cancer (MCF-7-ADR), and B16F0 melanoma cell lines, of which C26 and B16F0 cells were exploited for tumoring in BALB/c and C57Bl/6 mice, respectively. In most cases, increase in miltefosine percentage resulted in physically liposomal instability, increased Dox delivery and toxicity and reduced blood half-life of Dox. Overall, HePC 4% -PLD and PLD differed significantly in many respects and it was considered too toxic to be injected at the same dose (15mg Dox/ kg) as PLD. Although HePC 2% -PLD could extend the median survival time marginally in comparison to PLD, the concept of HePC- containing liposomes merits further investigation.