Preparation Of Nutriment-Loaded Nanoparticles By Supercritical CO₂ Antisolvent Techniques

Drug micronization ont only reduces the amount of administration, but also improves the bioavailability of actives. Comparing the products that prepared by traditional methods, drug micronized by supercritical CO₂ antisolvent (SAS) has some advantages such as small particle size, homogenous distribution, and low toxic solvent. The technology with wild reaction conditions is conducive to process heat-sensitive materials. In this study, using zein as carrier, resveratrol andβ-carotene as model drug, drug-loaded zein nanoparticles are prepared by SAS.The first part is the study of resvertrol-loaded zein nanoparticles. SAS was tested to prepare zein nanoparticles loaded with resveratrol. The effects of different operating parameters, such as pressure, temperature, and ratio on the loading weight of resveratrol were investigated. SEM and XRD were used to characterize the product, furthermore, in vitro drug release studies were also carried out. Results show that the yield of resveratrol decreases from 8.16% to 5.7% with the pressure from 8MPa up to 16MPa. When temperature rise from 35℃up to 55℃, the amount of drug loaded in zein nanoparticles increases from 7.23% to 8.38%. We also conclude that the yield of resveratrol increases from 2.16% to 17.9% at ratio from 1:30 up to 1:2. The nanoparticles with good sphericity and narrow size distribution can be prepared. The result of in vitro drug release studies proves that products exhibit a slower release than the single resveratrol.The second part is the study ofβ-carotene-loaded zein nanoparticles. Response surface methodology was used to optimize the preparation ofβ-carotene-loaded zein nanospheres with SAS. The mutual effect of the ratio betweenβ-carotene and zein, temperature, pressure was investigated. The morphology and size of particles were characterized. The stability ofβ-carotene loaded in nanoparticles was studied as well. Results show that the ratio has the most significant influence on the loading and encapsulation efficiency, followed by pressure and, finally, the temperature. Theβ-carotene loading reaches the maximum of 8.73%, when the ratio is 1:10, the temperature is 55℃,the pressure is 8MPa.Theβ-carotene loading achieves the maximum of 85. 4% , when the ratio is 1:30, temperature is 35℃,pressure is 16MPa. The structure ofβ-carotene-loaded zein particles is a Matrix with the sphere shape. The products have narrow size distribution from 100nm to 200nm. Anti-photolysis experiment shows that theβ-carotene encapsulated in nanoparticles is protected so that the stability is increased under exposuring to ultraviolet light.In summary, the rule of preparing nutriment-loaded nanoparticles by SAS has been mastered in this study. The effects of different operating parameters, such as pressure, temperature, and ratio on drug loading have been grasped. New information of using natural polymer as carrier to prepare nanoparticle delivery system has been provided.