en Toxicology Toxicology Experimental research article Experimental research article <p><strong>Introduction:</strong> It has been approved that selective serotonin reuptake inhibitors (SSRIs) may exhibit anti-proliferative or cytotoxic effects on several types of cancers. The aim of the present study was to evaluate the cytotoxic effects of a newly formulated niosome of Escitalopram oxalate on a colorectal cancer cell line.<br /> <strong>Methods:</strong> The niosomes were prepared using a thin layer hydration method, resulting in particles with a size range between 150 &ndash; 450 nm and spherical morphology. Moreover, its permeability release showed 25% in 4 hours. The cytotoxicity evaluation was performed using a quantitative colorimetric MTT assay.<br /> <strong>Results: </strong>The cell viability of colon cancer cells after treatment with niosomes and pure escitalopram reduced to 28.3 &plusmn; 0.83 % and 24.07 &plusmn; 0.56%, respectively. However, the cytotoxicity assay of escitalopram-loaded niosomes suggested that the anti-proliferative effect of the niosomal formulation of escitalopram was dose and incubation time-dependent.<br /> <strong>Conclusion:</strong> These results confirm the potential of the anti-proliferative activity of escitalopram-loaded niosomes. Further application to an in vivo model is needed to study various pharmacokinetic and pharmacodynamics parameters to establish its complete therapeutic potential.</p> Escitalopram, Cell viability, Niosome , MTT assay 307 318 http://ppj.phypha.ir/browse.php?a_code=A-10-1057-3&slc_lang=en&sid=1 Faten Eshrati Yeganeh ffyeganeh@gmail.com 3200319475328460033210 0000000256249812 No Islamic Azad University, Tehran, Iran Maryam Tabarzad tabarzad.m@gmail.com 3200319475328460033211 0000000199230639 No Shahid beheshti university of Medical Sciences, Tehran, Iran Hajar Khazraei hajarkhazraei@gmail.com 3200319475328460033212 0000000251017246 Yes Shiraz University of Medical Sciences: Shiraz, Fars, Iran Mahsa Bourbour colorectal@sums.ac.ir 3200319475328460033213 0000000159515090 No Alzahra University, Tehran, Iran