Preparation Of Nano Rice Starch And Study Of It As Drug Carrier

Nano starch is a kind of modified starch with smaller particle size below1000nm. It has good adsorption properties, biodegradability and biocompatibility and is widely used in modern pharmaceutical, chemical, environmental and other fields. In recent years, nano starch has become a hot research at home and abroad.In this research, rice starch was extracted by ultrasond associated neutral protease hydrolysis, with rice as raw material. The effects of ultrasond action mode, enzyme dosage, reaction time, hydrolysis temperature on the yield of rice starch were investigated by the single factor experiments. The results showed that yield of rice starch is the highest when enzymatic hydrolysis reaction is after ultrasond treatment. Under this ultrasond action mode, the effects of enzyme dosage, reaction time, hydrolysis temperature on the yield of rice starch were investigated by orthogonal experiment. The results showed that the enzyme dosage and reaction temperature were significantly affected on the yield of rice starch. The optimum conditions were determined:enzyme dosage9%(relative to dry rice weight), reaction temperature50℃, hydrolysis time2h. Rice starch yield of verification experiment was93.28%.With rice starch extracted as raw material, nano rice was prepared by ultrasonic united reverse microemulsion method. The effects such as starch concentration, ultrasond power, ultrasond time, oil/water ratio, crosslinker dosage on drug loading of nano starch were investigated by single factor experiments and orthogonal experiment. The results showed that starch concentration has significant influence on drug loading of nano rice starch, and the order of factors on the drug loading of nano rice starch was:starch concentration> oil/water ratio>ultrasond power> ultrasond time> crosslinker dosage. The optimum preparation conditions of nano rice starch were:rice concentration2%,oil-water ratio8:1. crosslinker dosage0.1g. ultrasond power400W. ultrasond time40min. Adsorption of nano starch on methylene blue was3.36mg/g by verification experiment.Nano rice starch was characterized. The average particle size of nano starch was239nm measured by laser particle size analyzer. Nano starch have absorption at1567cm-1scanned by infrared spectrometer and1567cm-1peaks is an important feature structure of chung-amide, therefore, starch was cross-linked significantly. The physicochemical properties of nano rice starch and native rice starch were comparative studied. Water absorption, apparent viscosity, gel strength, rheological properties, morphology, x-diffraction were investigated.Absorption and in vitro release of nano rice starch were studied with doxorubicin as a model drug. The effects of adriamycin initial concentration, absorption time and absorption temperature on drug adsorption were investigated. The results showed that when doxorubicin initial concentration was3mmol/L, absorption time was30min and temperature was37℃, the adsorption of nano starch on doxorubicin was the largest. In vitro release of doxorubicin raw materials and nano-containing doxorubicin was studied. Doxorubicin solution almost fully released in2h, however, the drug release of nano-starch was only73.9%dialyzed for8h.