| Puerarin is the effective portion of Puerariae Lobatae Radix,and possess the function of antioxidant,anti-inflammatory,reducing blood pressure,hyperlipidemic effect,decreasing myocardial oxygen consumption and other effects,so it is very effective in the prevention and treatment of cardiovascular and cerebrovascular diseases.However,puerarin is a low aqueous soluble and poor permeability drug due to its isoflavonoids structure.In addition,it is a fast metabolic drug.These properties of the drug typically limit its therapeutic applications.Fortunately,nanotechnology has opened a new window to enhance the aqueous solubility and cell membrane permeability of these drugs.In this paper,the subcritical water method had been used for the preparation of nanoparticles of puerarin to improve its water solubility and bioavailability.Furthmore,a transdermal route is considered as a better alternative to oral route in delivering drug into systemic circulation as it avoid fast metabolism and controlled drug release.The thesis is mainly divided into the following four parts:Part Ⅰ:Preparation of puerarin nanoparticles by using subcritical water methodPuerarin nanoparticles were prepared by using the subcritical water method.The optimum preparation technology was obtained as follows:liquid to solid ratio 215:1,preparation temperature 124℃,preparation time 25 min.After lyophilization,the average particle size of the nanoparticles was 137.93 nm and the Zeta potential was-34.77 m V,and the yield of nanoparticles was 94.01%.Under optimized experimental conditions,the nanoparticles were spherical and crystallinity decreased.FT-IR and HPLC showed that after subcritical water treated puerarin chemical structure has not changed.Moreover,puerarin nanoparticles showed high pharmacological activity compared to untreated puerarin.Part Ⅱ:Preparation of topically applied gel loaded with puerarin nanoparticlesPuerarin nanoparticles were incorporated into carbomer 980 based gels.Among the gel formulations,at p H 6.50,0.70%carbomer 980 used as matrix,5%glycerol as modifier,4%azone as osmotic promoter.TEM results showed that puerarin nanoparticles were uniformly distributed in the gel matrix,and this suggested good compatibility between the gel formulation and the puerarin nanoparticles.The puerarin nanoparticles showed high release rate than the raw particle from gel matrix and the dissolution profiles consistent with the first-order kinetic model according to the equation of Q=92.13(1-e-0.16t)（r=0.9873）,which can lead to a sustained release effect.Moreover,it was found that the transdermal effect of the nanoparticle preparation was better than that of the untreated drug gel,which tests via Franz diffusion cells.Part Ⅲ:Establishment of quality standard and stability investigation of external water gel loaded with puerarin nanoparticlesAccording to the requirements of 0114 gel in the 2020 edition of Ch P,puerarin nanoparticle gel quality evaluation,and preliminary stability investigation were carried out.The results showed that the gel was a milky,uniform,and fine semi-solid gel at room temperature with an average viscosity of 265.47 Pa·s and an average p H of 6.43.The stability test showed that the preparation was unstable at high temperatures,so it should be stored at low temperatures.Part Ⅳ:Pharmacokinetics and skin irritation of external hydrogel loaded with puerarin nanoparticlesThe pharmacokinetics of puerarin nanoparticles loaded gel and puerarin injection were investigated in rabbits.DAS2.0 software was used to process and analyze the blood concentration data.The results showed that the pharmacokinetic process of puerarin nanoparticle-loaded gel in rabbits was consistent with the two-compartment model,while puerarin injection was consistent with the three-compartment model.The maximum concentration of puerarin injection in rabbits 95.83μg/m L was 22.53 times the maximum concentration of gel 4.25μg/m L,but the bioavailability was only 1.60times that of gel,and severe hemolysis reaction had occurred at this concentration.The time for the puerarin injection to reach the peak of the blood drug was 0.083 h,and the time for the gel to reach the peak of the blood drug was 8h,which was 96 times of injection.Live rabbits were used to evaluate the safety performance of puerarin nanoparticle-loaded gel.The results showed that in single and multiple skin irritation experiments of the puerarin nanoparticle gel group,there were no skin irritation phenomena such as redness,swelling,and plaque.This project successfully developed a new preparation form for puerarin nanoparticles transdermal administration,which has the advantages of a relatively simple preparation process,stable preparation properties,safety,and effectiveness.It provided a new preparation form for puerarin to prevent and cure diabetic eye disease and theoretical guidance for the follow-up study on topical preparations of natural medicine. |
