| In recent years, vitamin A (vitamin A, VA) has been widely used in food, cosmetics and medicines. However, VA is vulnerable to some environmental conditions such as light, oxygen, which can accelerate its degradation, and limit its application. In this study, VA proliposomes were prepared by oil in water(O/W) and gelsiccation to enhance the stability of VA and make it more convenient in storage and applications, In this paper, We studied preparation technology, physical and chemical nature and stability of the VA proliposomes.,and and compared the physical nature of it with that of Roche VA microencapsules.We determinated the moisture, the bulk denstity, the solubility, the caesura angle, the size distribution and other physical properties of microcapsule products. calculated its payload. The results showed: the most convenient moisture content for proliposomes storage is 2.42%; bulk density is 0.57 g/cm3; solubility is 89.7%; zero angle is 37°, the flowablility is good; the payload is 14.00%. The average of microcapsules size is 2.05±0.33μm.We chose soybean lecithin as the raw materials, prepared the VA liposomes by O/W methods. In order to improve the stability of the liposomes, we prepared VA proliposomes by gelsiccation method. We optimized the prescription by orthogonal design, using the encapsulation efficiency as an index, and got the best prescription for liposomes preparation: the phospholipid concentration at 4%, the ratio of VA and phospholipids is 1:40, cholesterol and phospholipid's ratio is 1:8.We did some pharmaceutical pharmacy evaluation on proliposomes, the morphological changes of VA liposomes before and after gelsiccation was consider. The results showed: the particle size were 424.4±99 nm before gelsiccation and 430.5±120 nm after. the distribution of freeze-dried VA liposomes straggle slightly after gelsiccation. Encapsulation rates before and after gelsiccation were 83.1% and 79.8%. The stability investigation showed that gelsiccation liposomes process has no significant influence onproliposome appearance. Afert gelsiccation proliposomes pH increased slightly, an average particle size increased slightly and the encapsulation efficiency decreased slightly.Physical and chemical properties of proliposomes have been investigated. The results showed: after hydration, VA proliposomes present oval-shaped type ; its pH value is 6.42; and have good compatibility with 5% glucose, and no particle is larger than 1μm; Encapsulation efficiency remaines basically unchanged after hydration.We investigated the physics and chemistry stability of VA proliposomes. The results showed that the VA proliposomes are instable to light and heat. It is recommended to be preserved in dark at low temperature. Preservated in dark at 25℃, VA proliposomes stability elevates significantly; low temperature (4℃) and darkness can fulfill praeparatum stability .We Compared physical properties of microcapsules with that of proliposomes. The microcapsules particle size is bigger than that of proliposomes; its embedded efficiency reach the peak when the payload=14.00%, and be small at any other payload. The encapsulation efficiency of proliposomes did not effected by humidity, and the average encapsulation of it is 79.8%.
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