Preparation And Research Of Nano Resveratrol

Resveratrol,a highly polyphenolic substance,has received widespread attention in the last decades due to its extensive physiological activities and relatively less side-effects.However,resveratrol is a poorly water-soluble drug,whose bioavailability is limited by low absorptive amount and slow absorption rate in vivo.As a result,researchers are striving to explore different methods in order to achieve higher water solubility of resveratrol.According to the Ostwald-Freundlich formula and Noyes-Whitney formula,when other factors are expelled,there is a negative correlation between drug particle’s dissolving capacity and its volume.Therefore,nanorization of poorly water-soluble drug would be an effective way to improve its dissolving capacity and enhance its bioavailability.In this paper,reactive precipitation method and solvent anti-solvent precipitation method were used to prepare resveratrol powders with different effective contents and sizes,which include ultrafine resveratrol powder,resveratrol composite powder and resveratrol nanocomposite powder.Detailed contents are as follow:1.Ultrafine resveratrol powder was prepared by reactive precipitation method in beaker and subsequent drying process.In this research,preparation process conditions were optimized in order to prepare relatively smaller resveratrol particles.FT-IR and XRD tests indicate that the molecular structure and crystal form remain unchanged during the process.The specific surface area of ultrafine powder is 5-6 times bigger than the raw resveratrol and the dissolution rate turns out to be well improved.2.In order to improve efficiency and optimize process,Rotating Packed Bed was used to take the place of beaker and grinding miller was used to accelerate the dispersion of resveratrol filter cake.Various pharmaceutical excipients and the appropriate dosage were inspected.Resveratrol composite powders were obtained by freezing drying(FD)and spraying drying(SD).The specific surface area of composite powder(FD)is three times that of composite powder(SD).In the dissolution test,composite powder(FD)exhibited the best dissolution capacity,followed by composite powder(SD)and physical-mixed powder.Meanwhile,when added into artificial intestinal juice,composite powder showed better antioxidant activity than raw resveratrol.3.A preparation process route of resveratrol composite capsule was designed.Dry granulation was selected to improve the flowability of composite powder.According to the test,three times circulation of dry granulating could make composite powder meet eligibility criteria of flowability.The formula of self-made resveratrol composite capsule is as follow:36%resveratrol,3.5%PVP,3.5%SDS,50%mannitol,5%L-HPC,2%magnesium stearate.The weight variation of self-made capsules meets the standards of Chinese pharmacopoeia.By comparison with the commercial resveratrol capsule(Member’s Mark),self-made capsule exhibited better dissolution capacity in the artificial intestinal juice.4.Anti-solvent precipitation in a Y-shaped micro-channel device combined with spray drying technology was utilized to prepare resveratrol nanocomposite powder.Under the optimum conditions,transparent resveratrol nanosuspension with a mean size of 49 nm could be formed.After solidification by spray-drying,the obtained solid nanocomposite powder showed an excellent redispersibility.The characterization result shows that the dissolution amount of nanocomposite powder is about 1.3 times that of physical mixed powder in 120 min.Meanwhile,the free radical scavenging rate of nanocomposite powder is about 1.5 times that of raw resveratrol.XRD test indicates that resveratrol in nanocomposite powder exists in an amorphous form.