oprotective and enhanced anti-inflammatory activities of liposomal piroxicam formulation in lipopolysaccharide-stimulated RAW 264.7 macrophages Original Research (256) Total Article Views Authors: Chiong HS, Yong YK, Ahmad Z, Sulaiman MR, Zakaria ZA, Yuen KH, Hakim MN Published Date March 2013 Volume 2013:8 Pages 1245 - 1255 DOI: http://dx.doi.org/10.2147/IJN.S42801 Received: 15 January 2013 Accepted: 07 February 2013 Published: 25 March 2013 Hoe Siong Chiong,1 Yoke Keong Yong,1 Zuraini Ahmad,1 Mohd Roslan Sulaiman,1 Zainul Amiruddin Zakaria,1 Kah Hay Yuen,2 Muhammad Nazrul Hakim1,3 1Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Malaysia; 2School of Pharmaceutical Sciences, Universiti Sains Malaysia, Gelugor, Malaysia; 3Sports Academy, Universiti Putra Malaysia, Serdang, Malaysia Background: Liposomal drug delivery systems, a promising lipid-based nanoparticle technology, have been known to play significant roles in improving the safety and efficacy of an encapsulated drug. Methods: Liposomes, prepared using an optimized proliposome method, were used in the present work to encapsulate piroxicam, a widely prescribed nonsteroidal anti-inflammatory drug. The cytotoxic effects as well as the in vitro efficacy in regulation of inflammatory responses by free-form piroxicam and liposome-encapsulated piroxicam were evaluated using a lipopolysaccharide-sensitive macrophage cell line, RAW 264.7. Results: Cells treated with liposome-encapsulated piroxicam demonstrated higher cell viabilities than those treated with free-form piroxicam. In addition, the liposomal piroxicam formulation resulted in statistically stronger inhibition of pro-inflammatory mediators (ie, nitric oxide, tumor necrosis factor-α, interleukin-1β, and prostaglandin E2) than piroxicam at an equivalent dose. The liposome-encapsulated piroxicam also caused statistically significant production of interleukin-10, an anti-inflammatory cytokine. Conclusion: This study affirms the potential of a liposomal piroxicam formulation in reducing cytotoxicity and enhancing anti-inflammatory responses in vitro.