Preparation And Quality Evaluation Of Resveratrol PEG-PLGA Nanoparticles Drug Delivery System

Resveratrol(Res)is a natural non-flavonoid polyphenol compound with many pharmacological effects such as anti-tumor,anti-cardiovascular disease,anti-inflammatory,and anti-aging.However,due to its poor water solubility and easy decomposition under light,its bioavailability is low,which leads to poor therapeutic effects and limits its clinical application.This topic is mainly aimed at improving the water solubility,light stability and sustained release of Res,and using monomethoxypolyethylene glycol-polylactic-glycolic acid copolymer(polyethylene glycol poly(d,l-lactic-co-glycolic)acid,PEG-PLGA)as a carrier to prepare resveratrol-loaded poly Ethylene glycol-polylactic acid glycolic acid copolymer nanoparticles(Res-PEG-PLGA-NPs),and its preparation process,quality evaluation,preliminary investigation of stability and in vitro cytotoxicity and other related research.This article established Res in vitro analysis methods,including ultraviolet spectrophotometry and high performance liquid chromatography.Res-PEG-PLGA-NPs were successfully prepared by the emulsification-solvent evaporation method with PEG-PLGA as the carrier.The free Res and Res-PEG-PLGA-NPs were separated by ultrafiltration.Taking the encapsulation efficiency,drug loading and particle size as evaluation indicators,the prescription and preparation process are single-factor investigation,and the surfactant concentration,carrier concentration and drug concentration are three factors and four levels of experiment through the star point design-response surface method.The optimal prescription was screened and verified with the encapsulation efficiency and drug loading as evaluation indicators,and the optimal prescription process for Res-PEG-PLGA-NPs was obtained:Precisely weighing the appropriate amount of PVA-1788,dissolved in 400 mL water bath heating to dissolve,the formation of PVA concentration of 1.02%aqueous phase.83.5 mg PEG-PLGA was dissolved in 10 mL acetone,and then add 138.5 mg Res,the organic phase was formed by ultrasonic mixing.Add the water phase to the 10%water phase with 200 W ultrasonic power,ultrasound for 1 min(ultrasound 3s,interval 4s),then inject it into the remaining aqueous phase with an injection under 700 rpm/min magnetic stirring,stir at room temperature for 2 hours,and filter through a 0.45 μm filter membrane to obtain Res-PEGPLGA-NPs with a light blue opalescence,having an encapsulation rate of 87.06±0.59%and a drug loading of 49.63±0.74%.The results of parallel experiments show that the method fits well.The Res-PEG-PLGA-NPs solution prepared by the optimal prescription was evaluated for quality evaluation.Res-PEG-PLGA-NPs is a uniform translucent transparent liquid with light blue opalescence.Transmission electron microscopy observed that Res-PEG-PLGA-NPs had a spherical structure with relatively uniform size and good dispersion without adhesion.The particle size is about(261.8±27.31)nm,the PDI is(0.19±5.81),the Zeta potential is(24.30±0.66)mV,and pH is about 7.15,the system is stable.Through the preliminary investigation of stability,although the Res-PEG-PLGA-NPs improved the light stability,under light conditions in one month the Res-PEG-PLGA-NPs with light blue opalescence gradually turned into yellow transparent solution,the encapsulation efficiency and drug loading gradually decrease;white floccules appeared gradually within 6 months,and the contained Res almost completely degraded;the particle size,encapsulation efficiency,and drug loading of the ResPEG-PLGA-NPs under dark conditions in the first 6 months did not change significantly.A small amount of white floccules appeared at 12 months,and the encapsulation rate and drug loading reduce little.Therefore,long-term storage needs to be kept at low temperature and avoid light.The Res-PEG-PLGA-NPs solution prepared by the optimal prescription was analyzed by FT-IR spectroscopy.The results showed that Res was successfully encapsulated in the PEGPLGA and remained the structural characteristics of the trans space,and the structure of Res and PEG-PLGA did not change after drug loading.The result of differential thermal analysis shows that Res exists in Res-PEG-PLGA-NPs in an amorphous state.Using pH7.4 phosphate buffered saline(PBS)as the release medium,the in vitro release of Res-PEG-PLGA-NPs was evaluated.Compared with Res,Res-PEG-PLGA-NPs has certain sustained release characteristics and can release continuously for 24 hours,the cumulative release rate can reach about 88.21%.In vitro cytotoxicity experiments used MTT method to detect the cytotoxicity of Res,blank PEG-PLGA-NPs and Res-PEG-PLGA-NPs to human gastric cancer cells SGC-7901.The results shows that blank PEG-PLGA-NPs has almost no toxic effect on cells;compared with Res under the same concentration gradient,Res-PEG-PLGA-NPs cell survival rate is lower.After culturing the cells for 48 h,The IC50 value of Res is 2.06 times that of Res-PEGPLGA-NPs,which proves that its cytotoxicity is significantly improved once again(P<0.05).This article uses the emulsification solvent evaporation method to prepare Res-PEGPLGA-NPs successfully.Compared with the Res bulk drug,Res-PEG-PLGA-NPs has improved water solubility,light stability,and achieved sustained release.Meanwhile it also has stronger cytotoxicity to human gastric cancer cell SGC-7901.