Preliminary Study On Preparation And Phamaceuticfeaures Of Breviscapine-in-cyclodextrin-in-liposome

Objective: Breviscapine is the whole grass of Asteraceae Erigeron breviscapus,which contains mainly scutellarin. As breviscapine can increase blood flow, improve cardiac and cerebral microcirculation, it is used for the treatment of angina,coronary heart disease, cerebral infarction and other cardiacvascular and cerebralvascular diseases.However,it’s poor water solubility,low bioavailability and short half-life limit its clinical application.Drug cylodextrin complex in liposome has been investigated as a new strategy to combine the relative advantages of CDs and liposome into one system,namely drug-in-CD-in-liposome(DCL) system.Cyclodextrin,which has a tubular structure with hydrophlilic group outside and hydrophobic group inside,bonds with drug through hydrogen bond, van der Waals’ force etc,but these forces are not stable. Liposomes,similar to cell membrane, have a bilayer structure,which is mainly formed by phospholipids and cholesterol. Hydrophilic drugs are encapsulated within an aqueous compartment of liposomes, whereas hydrophobic drugs are entrapped within the lipid bilayer.Liposome can make drug avoid the rapid removement from plasma,prolong the circulation in body and it can solve the decomposition of inclusion complex.Therefor,this study focus on preparing breviscapie-DCL to improve the solubility,prolong the circulation time in vivo.Methods:The determination of breviscapine’s solubility in different lipid wa performed and related high-performance liquid chromatographic(HPLC)method to test the concentration of scutellarin in breviscapine was established, taking scutellarin in breviscapine as an indicator.Encapulation efficiency as an indicator,the saturated water solution method and ultrasonic method were tested for the preparation of breviscapine inclusion complex.Aslo,a single factor test was performed.Then we screen the formulation by orthogonal experiment.After preparing breviscapine-DCL by thin film method, ultracentrifugation was used to measure the encapsulation efficiency of breviscapine-DCL.Taking encapsulation efficiency as an indicator,the single factor study was performed,on the basis of this,Central Composite DesignResponse Surface Methodology was used to optimize breviscapine-DCL formulation.The in vitro release behaviors of breviscapine, breviscapine inclusion complex and breviscapine-DCL was investigated by dissolution apparatus. The mechanisms of drug release from the different preparation of breviscapine were investigated by making the release curves and fitting data with different models.10 SD rats,randomly divided into the control group of breviscapine and the breviscapine-DCL group, were used to examine the pharmacokinetic behaviors after single dose intravenous injection.HPLC detection method for the analysis of scutellarin concentration in rat plasma was established.The plasma concentration versus time curve was obtained, and the data was analysed using PK-Solver, which were analyzed to perform a preliminary exploration on pharmacokinetic characeristicsin rats.The stability of breviscapine-DCL were investigated by temperature and lighting condition test and long-term stability test.Results:HPLC detection method for measure the concentration of scutellarin was established and the solubility of breviscapine in different solution was test. Breviscapine-DCL was prepared by thin film method and encapsulation efficiency was measured by ultracentrifugation.After using single factor test and central composite design-response surface methodology,the optimize formulation is SPC/Drug were 64.82 and SPC/Chol were 6.25 and OD were 0.878±0.03.The in vitro release behaviors of breviscapine, breviscapine inclusion complex and breviscapine-DCL was investigated and the result showed that breviscapine-DCL have obviously sustained effect.The fitting results in vivo compartmental model display that the breviscapine-DCL was consistent with two compartment model. Area under curve(AUC) value of breviscapine-DCL was 1229.11 min·μg·m L-1, 21.76 times of breviscapine solution,while the elimination half life was 29.76 min,2 times of breviscapine solution,which showed the breviscapine-DCL have obviously sustained effect in vivo.The results of stability experiments showed stability of breviscapine-DCL is influenced by light and temperature, so the preparation should be stored away from light at 4℃.Conclusion:Breviscapine-DCL was prepared by thin film dispersion method.The optimal formulation showed a high encapsulation efficiency and obvious sustained release effect in vitro and in vivo. The stability experiments showed the preparation should be stored away from light at 4℃.