Control of the Release of Curcumin from Microemulsion by Ultrasound

• Main Authors: Hsu-chih Chen, 陳旭志
• Other Authors: Mei-Hwa Lee
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/25234792744935908345

碩士 === 義守大學 === 材料科學與工程學系碩士班 === 93 === Curcumin (diferuloylmethane), the yellow pigment in turmeric and curry, was used extensively in food and chemical industry. It was found to exhibit anti-oxidative and anti-inflammatory properties. Many research reports indicated that curcumin can induct apoptosis and suppress the formation of procarcinogens by various kinds of mechanism. Curcumin with polyphenol structure was water insoluble and scarcely dissolved in organic phase. This property led to its poor bioavailability in vivo. Besides, curcumin was unstable at neutral-basic pH values and serum-free medium. In this study, the first aim was to find stable microemulsions containing curcumin encapsulated with pharmaceutically acceptable ingredients, lecithin and Tween 80, to enhance bioavailability of curcumin. Then the ultrasound, frequency 40 kHz, was employed to investigate factors that influence controlled release of curcumin entrapped in microemulsion droplets, including pH value of buffer solution, full power ratio of ultrasound, concentration of curcumin in oil phase and mole ratio of lecthin/tween 80 . A stable microemulsion was successfully prepared containing curcumin, using D.I. water, EO as oil phase, lecithin and tween 80 as surfactants. For estimating the in vitro stability in a stable microemulsion with curcumin encapsulated, it was found that microemulsion droplets did not release to water and destroy its structure near 99 % in dilute pH 7.4 PBS with various volume after two days. Thus, the solubility and stability of curcumin was also improved in this oil-in-water microemulsion system. The study of controlled release by 40 kHz ultrasound showed that ultrasound could enhance the release of curcumin from microemulsion droplets under either basic or acidic conditions. Release rates with ultrasound applied were more than 1000-fold higher than control. When full power ratio became higher, initial release rate was larger. Under the same lecithin purity, initial release rate rose as full power ratio became higher. When concentration of curcumin in oil phase increased, initial release rate decreased. Under the same lecithin purity, initial release rate rose as concentration of curcumin in oil phase became lower. But initial release rate remained the same as lecthin purity equaled to 99%. The initial release rate decreased with the increased in mole ratio of lecithin/tween 80 which was between 0.14 and 0.6.