IntroductionLutein (C40H56O2, MW = 568.87) whose molecular structure isshown in Fig. 1 is one of the most important active pharmaceuticalingredients (APIs), which is now widely used as natural colorants.In addition, due to its high antioxidant activity, the compoundexhibits other positive effects such as reducing the failure of theeyesight due to age-related macular degeneration, as well as fight-ing against coronary heart disease and cancers [1,2]. Althoughlutein can be found in various fruits and vegetables, one of the rich-est natural sources of lutein is known to be marigold flowers [3].Therefore, a number of studies have been conducted on extrac-tion and purification of lutein from this source [4.6]. Recently, wesuccessfully employed preparative chromatography technique topurify marigold derived lutein to the purity up to 97%. In this pro-cess, silica gel was used as a stationary phase and a mixture ofhexane:ethyl acetate (70:30 v/v) was used as a mobile phase [7].Despite having high medicinal activities, many APIs and luteinalike, are of low bioavailability due largely to their low solubility inwater [8]. An improvement in aqueous solubility of an API can gen-erally be achieved by micronizing it to smaller particles. As a result,the surface area increases, and thus the dissolution rate increases.