November-December 2018 Indian Journal of Pharmaceutical Sciences 1039 Research Paper RA is least prevalent and does not accumulate over time in body as it is metabolized rapidly [10] . Liposomal drug delivery systems are found to be effective for a variety of drugs with such limitations through sustained drug release, prevention of exposure toxicity and enhanced drug stability [11] . This investigations aim was to formulate a liposomal 9-cis- RA delivery system using 1,2-distearoyl-sn-glycero- 3-phosphocholine (DSPC) and cholesterol as lipid core for the treatment of lung cancer. Characteristics of this liposomal 9-cis-RA preparation such as size, morphology, stability and in vitro drug release property evaluated. Percent encapsulation and retinoid level in cell lines also were measured. The anticancer effect of liposomal 9-cis-RA formulation on A549 cell line was evaluated using MTT and trypan blue assays and was compared with that of free 9-cis-RA. Lung cancer being one of the leading causes of cancer deaths in the US [1] and worldwide, need special attention pertaining to development of new therapeutic regimens. Targeted drug therapy using liposomes is an intense research area in recent years for cancers having complex molecular changes during carcinogenesis. A very common human lung cancer cell line, A549, established from lung adenocarcinoma of epithelial origin in 1972 is being used for most of the anticancer and genotoxic studies for lung cancer [2-4] . 9-cis-Retinoic acid (9-cis-RA) binds and activates both its receptors retinoid X receptor (RXR) and retinoic acid receptor (RAR) [5] for producing molecular actions, among the both it binds RXRs with greater affnity [6] . Many in vivo and in vitro assays on tumour cell proliferation, differentiation and apoptosis have proven the 9-cis-RA as a promising therapeutic agent [7] . It is synthesized and approved as a potential therapeutic agent by the USFDA to treat Kaposi sarcoma [8] . But still its clinical use is under trials due to limiting challenges such as instability, toxic side effects, chirality (isomerization), targeted reach, poor pharmacokinetics, and development of drug resistance on prolonged use [9] . It was reported that, among the isomers of retinoid, 9-cis- DSPC/Cholesterol Nano-formulated 9-cis-Retinoic Acid has Potent Therapeutic Effect on A549 Cell Line V. M. BERLIN GRACE*, V. SANDEEP, S. VISWANATHAN AND B. ESTHER SATHYABAMA Department of Biotechnology, Karunya Institute of Technology and Sciences, Coimbatore-641 114, India Grace et al.: Therapeutic Effect of Nano-formulated 9-cis-Retinoic acid The main objective of the present work was to develop liposomal nano-formulation for 9-cis-retinoic acid using di-stearoylphosphocholin/cholesterol mixture, to characterise and to evaluate its anticancer effect on A549 human lung cancer cell lines. The liposomes were prepared using thin flm formulation method and characterization of particle size and shape were carried out employing dynamic light scattering and scanning electron microscopy techniques, respectively. The level of drug entrapment into the liposomes and liposomal stability were analysed using spectrophotometry and expressed in terms of percent entrapment. The level of 9-cis-retinoic acid in treated cells also was assayed using spectrophotometry. In vitro drug release level evaluated using a dialysis bag. The anticancer effect was studied using MTT and trypsin blue assays in human lung cancer cell line. The drug entrapment level achieved was 83.33 %. Viability of cancer cells was signifcantly reduced after liposomal 9-cis-retinoic acid treatment. From these results it could be concluded that the liposomal 9-cis-retinoic acid was easily taken up by the A549 cells compared to free 9-cis-retinoic acid, which might have enhanced the anticancer activity observed in this study. Key words: 9-cis-Retinoic acid, liposomes, lung cancer cell lines, SEM, DLS, anticancer activity *Address for correspondence E-mail: berlinbiochem@gmail.com This is an open access article distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License, which allows others to remix, tweak, and build upon the work non-commercially, as long as the author is credited and the new creations are licensed under the identical terms Accepted 24 September 2018 Revised 23 March 2018 Received 27 March 2017 Indian J Pharm Sci 2018;80(6):1039-1044