Development and evaluation of magnetic microemulsion: tool for targeted delivery of camptothecin to BALB/c mice-bearing breast cancer.

Development and evaluation of camptothecin-loaded-microemulsion (ME) and -magnetic microemulsion (MME) for passive/active-targeted delivery to BALB/c mice-bearing breast cancer. Based on the pseudo-ternary phase diagrams camptothecin-loaded-MEs and -MMEs were developed using benzyl alcohol:Captex 300 (3:1), TPGS:Tween 80 (2:1) and water. Furthermore, characterized for their droplet size distribution, magnetic susceptibility and effect of droplet size in plasma and evaluated for in vitro and in vivo targeting potential, drug release, haemolytic potential, cytotoxicity, genotoxicity, in vivo biodistribution and lactone ring stability. Drug-loaded MEs showed uniform droplet distribution, extended drug release (76.07 ± 4.30% at 24 h), acceptable level of haemolytic activity (<20%), significant cytotoxicity (129 ± 3.9 ng/mL) against MCF-7 cancer cells and low DNA damage in lymphocytes. Targeting potential of MMEs was documented in 4T1 breast cancer-induced BALB/c mice. MMEs were concentrated more at the target tissue on introduction of external magnetic field. In vivo biodistribution study documented the active targeting of 5067.56 ± 354.72 ng/gm and passive targeting of 1677.58 ± 134.20 ng/gm camptothecin to breast cancer from MME and ME, respectively. Lactone stability study shows around 80% of the lactone stable at 24 h. Developed ME and MME may act as a promising nanocarrier for efficient targeting of breast cancer tissues.