Pharmacokinetics Investigation Of Liposomes Encapsulating Schisandra-β-cyclodextrin Inclusion Complexes

Schisandra is the dry and ripe fruit of the Schisandra of the Magnolia branch plant, the fruit of Schisandra have different origin, the origin of the northeast of China is called Schisandra chinensis( Turcz.) Baill..Schisandrin, schisantherin and γ-schizandrin are the main active ingredients of hepatoprotective activty of Magnoliaceae Schisandra, modern pharmacological research show that schisandrin, schisantherin and γ-schizandrin with block liver cell damage, leading to H2O2 or CCl4liver injury protective effect, improve liver function and inhibition of hepatic collagen fiber formation and cell protection hepatoprotective effect.The current clinical application of Schisandra chinensis based liver protecting preparation of dozens, represent the main drugs have bifendate, Gan De Ning and Hugan tablets and forms mainly concentrated in traditional tablets, pills, syrups, granules, capsules and other. But schisandrin, schisantherin and γ-schizandrin are lipophilic and hardly soluble in water. Have been described in the literature, for the lipophilic and insoluble drugs in water, penetrating, low solubility characteristics, therefore in the gastrointestinal tract of low solubility, dissolution rate is slow, resulting in the oral bioavailability of low degree of disadvantage [1]. In order to improve oral absorption effect and biological utilization degree and its tissue targeting, the active ingredients of protecting liver, schisandrin, schisantherin and γ-schizandrin the as the index in this study, research and development of new delivery system of liposomes encapsulating Schisandra-β-cyclodextrin inclusion complexes and to study the pharmacokinetics and targeting of rats by gastric perfusion.Our thesis could divide into four parts: 1. The selection of the optimum extraction technology of schisandrin, schisantherin and γ-schizandrin with the orthogonal experiment method; 2. The research of schisandrin, schisantherin and γ-schizandrin of inclusion complexes; 3.The establishment of delivery system of liposomes encapsulating schisandrin, schisantherin andγ-schizandrin of inclusion complexes; 4. Pharmacokinetics investigation of liposomesencapsulating schisandrin, schisantherin and γ-schizandrin of inclusion complexes for hepatic targeting in rats.Firstly, to extract schisandrin, schisantherin and γ-schizandrin. By orthogonal experiment to select extraction method of schisandrin, schisantherin and γ-schizandrin, high performance liquid chromatography method was used to determine the content, reflux and ultrasonic extraction method has been investigated. By comparative analysis and analysis of variance, and ultimately determine the reflux extraction method is better than the ultrasonic extraction method, therefore,determine the optimum extraction technology is 85% alcohol, refluxing and extracting for 3 h and material liquid ratio: 1:8 and extraction times: 2 times. The extraction content of schisandrin,schisantherin and γ-schizandrin was measured by HPLC method, the results are 5.484 mg · g-1,0.356 mg·g-1 and 2.679 mg·g-1, respectively.Secondly, to research inclusion complex of schisandrin, schisantherin and γ-schizandrin. By orthogonal experiment to select inclusion method of schisandrin, schisantherin and γ-schizandrin what is the main active compounds og schisandra chinensis, and high performance liquid chromatography method was used to determine the content, the effects of two inclusion methods including the saturated water solution method and ultrasonic method, the comprehensive evaluation, contrast analysis and analysis of variance, and ultimately determine the saturated water solution method is superior to ultrasonic method, therefore, to determine the best inclusion process:(ml: G) ratio: 1:2, temperature: 60 ℃, stirring time: 30 min. The entrapment efficiency of schisandrin, schisantherin and γ-schizandrin was measured by HPLC method, the results are12.48%, 36.54%, and 52.65%, respectively.By Fourier transform infrared spectroscopy and infrared microscopy confirmed the formation of inclusion complexes, through measured dissolution rate of active components in inclusion complexes and the results show that great improvements of dissolution rate of target components of schisandra chinensis after preparation of inclusion complexes of schisandra chinensis within 6 h and solubility than single extract improves with the trend of slow growth trend, maintaining the certain dissolution rate.Thirdly, to research liposomes encapsulating Schisandra- β-cyclodextrin inclusion complexes and schisandra including schisandrin, schisantherin and γ-schizandrin. According to the literature research, liposomes encapsulating Schisandra-β-cyclodextrin inclusion complexes wasprepared through diaphragm-rotation-evaporation method and this method is simple, the stability is good, the particle size is even, the encapsulation efficiency is high and the loading quantity is high, the diameter is 470.6 nm, Zeta-potential is 4.53 m V, which belongs to the single chamber type liposomes. The average drug loading of schisandrin, schisantherin and γ-schizandrin was measured by HPLC method, the results are 7.65 %, 1.36 % and 4.22 %, respectively, the average encapsulation rate results are 87.0 %, 84.8 % and 89.7%, respectively. 4 ℃ to save 30 days,appearance, color, particle diameter, zeta potential and drug loading were not changed. Xu Dongwei[2] study the pomelo peel prime liposomes stability in the temperature of 4 ℃, the literature were investigated liposome agent in 0, 1, 2 month appearance, encapsulation rate and grain size in order to evaluate the stability, the study results showed that the change is not obvious and have good stability; Yuan Duanfeng in order to the stability evaluation of liposomes and study T7 peptide and cell penetrating peptide Tat double modified liposomes at 37 ℃ for 24 h the appearance, particle size, zeta potential and turbidity; 4-8 ℃ for 0 d, 30 d in the appearance,particle size, zeta potential and turbidity. The effects of the liposome stability is good [3].In the end, to study the pharmacokinetics and hepatic targeting of the liposomes encapsulating Schisandra-β-cyclodextrin inclusion complexes. Rats were fed with the iposome of the inclusion compound of schisandra chinensis and extract of schisandra chinensis respectively by intragastric administration. After samples treatment, the drug concentration in blood and tissue at different time was determined by high performance liquid chromatography. The pharmacokinetic parameters and target tropism were calculated. The pharmacokinetic experiments results show that the best drug pharmacokinetic model of schisandrin, schisantherin andγ-schizandrinare in line with the weighting factor for 1 one compartment model. The t1/2 and AUC(0-t)of schisandrin and γ-schizandrin were longer and the CL was decreased, while that the t1/2and AUC(0-t) of schisantherin were longer and the CL did not changed.Calculation of hepatic targeting based on pharmacokinetic parameters. The results showed that the Re of SD in the liver, heart, spleen, lung and kidney were 2.662, 1.513, 2.176, 1.927 and2.400,respectively and the Re of SZ in the liver, heart, spleen, lung and kidney were 3.034, 2.084,1.709, 1.978 and 2.522,respectively. The results also showed that the targeting efficiency(Te) of SD in SCL in the liver, heart, spleen, lung and kidney were 36.832%, 9.851%, 10.384%, 13.428%and 29.505%, respectively and the targeting efficiency(Te) of SD in SES in the liver, heart, spleen,lung and kidney were 31.110%, 14.637%, 10.730%, 13.575% and 30.378%, respectively; The results also showed that the targeting efficiency(Te) of SZ in SCL in the liver, heart, spleen, lung and kidney were 35.995%, 9.179%, 10.316%, 15.600% and 28.910%, respectively and the targeting efficiency(Te) of SZ in SES in the liver, heart, spleen, lung and kidney were 28.482%,10.571%, 14.491%, 17.188% and 29.268%, respectively. The results also showed that the relative targeting efficiency(RTe) of SD in liver, heart, spleen, lung and kidney were 18.393 %,-32.698 %,-3.225 %,-1.083 % and-2.874 %, respectively and the relative targeting efficiency(RTe) of SZ in liver, heart, spleen, lung and kidney were 26.378 %,-13.168 %,-28.811 %,-9.239 % and-1.223 %, respectively. Results showed that SCL compared with the SES, SD and SZ has obvious hepatic targeting, but SZ in the organization mainly drug dynamic parameters only in the liver with statistical data, other tissues only in a moment point with data, the experimental data could not be were statistically analyzed. The reasons may be due to the low content in schisandra chinensis and the specific hepatic targeting of ST.Analysis to the experimental results above, we can draw a conclusion, hepatoprotective active ingredients of schisandra chinensis made liposomes entrapped drug complex in rats with significance hepatic targeting, compared with the SES can significantly improve the bioavailability of Schisandra hepatoprotective therapy.The innovative points of this paper are obtained with the best extraction process of schisandrin, schisantherin and γ-schizandrin as the index and the HPLC method was established for the simultaneous determination of three active components in the determination of the amount of a single component by the method of the determination of the components of a single component. Screened preparation method of inclusion complexes of extraction of schisandra chinensis and has constructed a new drug delivery system of he liposomes encapsulating Schisandra-β-cyclodextrin inclusion complexes what have the obvious hepatic targeting and improved the oral bioavailability of schisandra chinensis in the treatment of liver diseases.Therefore, the liposomes encapsulating Schisandra-β-cyclodextrin inclusion complexes is a new type of nano drug loading dosage form with good prospect.