Studies On The Matrine-loaded Albumin Nanoparticles Drug Delivery System

Matrine(MAT) ,a kind of alkaloid extracted from the well known Chinese herb Sophora Flavescens Ait S.Q lopecuroioles L and S. snbprostrata chun at T. Chon, which has many pharmacologic actions such as anti-virus,anti-hepatic fibrosis, anti-tumor, immunological regulation and so on,and it has been used in the treatment of acute / chronic hepatitis extensively.As carrier material,bovine serum albumin(BSA) may be very promising because of their biodegradability, lack of toxicity and antigenicity, stability, shelf life, controllable drug-release properties. Therefore, we chose MAT as the model drug and BSA as the drug carrier, and prepared matrine-loaded albumin nanoparticles (MAT-BSA-NP) by a coacervation method and chemical cross-linking with glutaraldehyde in our investigation. The formula and technology for preparing MAT-BSA-NP colloidal solution were optimized by the uniform design method, with the entrapment efficiency as the criterion, and its freeze-dried sample for injection was also systematically studied. The release kinetics in vitro ,characteristics of distribution and Pharmacokinetics in vivo were examined. MAT-BSA-NP were expected to reach the aim of enhancing its therapeutic efficacy of hepatitis through hepatic targeting and decreasing its side effects.The optimized parameters were as follows: the glutaraldehyde -BSA ratio was 2.73μg·mg^-1 , the MAT was 9.1mg,the concentration of BSA in water was 2.35%, the cross-linking time was 2.4h, the stirring rate was 700 r·min^-1,and the standing time was 1.5h. The entrapment efficiency ,actual drug loading and yield of the nanoparticles were (84.25±0.95)%, (6.06±0.08)% and (87.47±0.74) %, respectively. Through the observation of transmission electron microscope, we found that the nanoparticles we prepared were sphere-like and regular. The size distribution of the nanoparticles was narrow, with the average particle diameter of( 323.7 ±12.5 )nm.The Zeta potential was (-16.92±0.39) mV.The formula of freeze-dried MAT-BSA-NP for injection was established based on the criterious of its appearance,color and redispersibility. The final established freeze-dried method was as follows: the protective agent was manicol with the concentration of 5%, the force-freeze temperature was -80℃, the force-freeze time was 24 h, and the freeze-dried time was 36 h. The comparison between the nanoparticles before and after freeze-dried procedure showed that freeze-drying had little effects on the entrapment efficiency, drug-loading, the particle diameter and Zeta potential of the nanoparticles. It was demonstrated by differential scanning calorimetry (DSC) and X-ray diffractometry (XRD) that MAT existed in the form of amorphous in the nanoparticles. The initiatory stability research showed that the freeze-dried MAT-BSA-NP could be stored at 3-5 ℃ or 20-25 ℃ for 3 months.The in vitro release properties of the freeze-dried MAT-BSA-NP for injection was evaluated by ultrafiltration/centrifugation. The results showed that the drug release pattern was in accord with two phases kinetics equation,having sustained-release character: 100-Q=0.476e^-0.351t+0.3253e^-0.0322t, r_α =0.9985, r_β=0.9987We utilized the HPLC method to determine and compare the content of MAT in different tissues of mice following the tail intravenous injection of MAT solution and freeze-dried MAT-BSA-NP for injection. The results showed that being packed in nanoparticles, the distribution of MAT in liver and spleen were all enhanced. Moreover, the mean retention time in these tissues was also prolonged. Therefore, MAT-BSA-NP were helpful for MAT to improve its therapertic efficiency and achieve a long-term effect. The results of pharmaceutics showed that, the encapsulation of MAT in MAT-BSA-NP was remarkably effective in prolonging its blood circulation time and possessing a stable blood drug level. Pharmacokinetic parameters and the best compartment method were obtained using the Practical Pharmacokinetic Program-DAS 2.0. The results showed that both preparations' Pharmacokinetics process were conformed to the two-compartment model. The pharmacokinetic equation of MAT solution and freeze-dried MAT-BSA-NP for injection were C=8.096e^2.23t+2.371e^-0.449t and C=4.675e^-0.932t+0.722e^-0.07t, respectively. The major calculated parameters of the MAT solution group were as follows: T_1/2α=0.311h, T_1/2β=1.543h, MRT_0-∞=1.216h, CLz =4.264 L/h/kg , AUC=9.38h·μg·ml^-1 , Meanwhile, the major calculated parameters of the freeze-dried MAT-BSA-NP group were as follows: T_1/2α=0.744h, T_1/2β=9.866h, MRT_0-∞=9.373h, CLz =2.405 L/h/kg, AUC =16.632 h·μg·ml^-1 The results indicated that BSA nanoparticles could be a potential carrier for MAT to prolonged elimination half life and increased bioavailability.MAT-BSA-NP are novel targeting drug delivery system, which were prepared first time in this research. The results which not only offered reference and experience for hepatic targeting drug delivery system but also brought new ideas to design and develop a new type drug delivery system for hepatitis .