PT - JOURNAL ARTICLE AU - Akhayachatra Chinsriwongkul AU - Praneet Opanasopit AU - Tanasait Ngawhirunpat AU - Natthan Chareansriwilaiwat AU - Warisada Sila-On AU - Uracha Ruktanonchai TI - Physicochemical Properties of Lipid Emulsions Formulated with High-load All-<em>trans</em>-Retinoic Acid DP - 2007 Nov 01 TA - PDA Journal of Pharmaceutical Science and Technology PG - 461--471 VI - 61 IP - 6 4099 - http://journal.pda.org/content/61/6/461.short 4100 - http://journal.pda.org/content/61/6/461.full SO - PDA J Pharm Sci Technol2007 Nov 01; 61 AB - The objective of this study was to formulate high loading with good stability of all-trans retinoic acid (ATRA) lipid emulsion. Lipid emulsions loaded with ATRA were composed of lecithin, medium chain triglyceride and poloxamer-188 or polysorbate-80. The formulation factors in a particular type and amount of oil, emulsifier, and co-emulsifier on the physicochemical properties (i.e., particle size, size distribution, droplets surface charge, pH, percentage yield, drug release, and stability of lipid emulsions) were studied. The particle size of ATRA-loaded lipid emulsions was in the nano-size range of 124.4–378.2 nm with the narrow polydispersity index of 0.04– 0.09, which decreased as the amount of co-emulsifiers was increased. The amount of ATRA released from lipid emulsions was operated using a dialysis bag. The receptor medium was ethanol:polysorbate-80:water (10:15:75), adjusted to pH 8.5. ATRA release kinetics in this study were found to follow zero-order kinetics. As the concentration of co-emulsifiers increased, the flux of ATRA released from the lipid emulsions increased. In stability studies, the higher the amount of co-emulsifiers added, the lower the crystallization of ATRA was found. The percentage yield of ATRA was retained at about 70–90% and 60–72% after storage for 60 days at 4 °C and 25 °C, respectively. These results show a successful incorporation of ATRA into lipid emulsions with high loading capacity and good stability.