Preparation And Study Of Tetrandrine-phospholipid Complex

Tetrandrine(TET)has a wide range of pharmacological properties,is a powerful anti-silicosis drug and anti-cancer synergistic drug,but it is extremely difficult to dissolve in water and its oral bioavailability is low,its clinical application is limited.Soybean phosphatidylcholine is an important component of human biofilm,and the Phospholipid complex(PLC)formed by its combination with drugs in a certain ratio could improve the amphipathic properties of drugs and enhance the oral bioavailability of drugs.In this paper,Tetrandrine-phospholipid complex(TET-PLC)was prepared and systematically studied to solve the problem of TET insoluble in water and low oral bioavailability.The main research contents of this paper are as follows:1.A high performance liquid chromatography analysis method was established to detect the content of TET in TET-PLC,the method has good specificity,good linear relationship(R~2?0.999)in the range of 5-120?g/m L,precision and accuracy could meet the requirements for the determination of TET in TET-PLC.The results of TET stability investigation showed that TET was stable to humidity and temperature,but not to light,so the preparation process of TET-PLC should be carried out under the condition of avoiding light.2.In this paper,TET and soybean phosphatidylcholine were used as raw materials and TET-PLC was prepared by solvent evaporation method.The complexation rate was used as the evaluation index,the effects of solvent,TET concentration,the mass ratio of phospholipid and TET,temperature and time on the complexation rate were investigated by single factor experiment.The results of single factor investigation were as follows:the complexation rate was higher when the solvent was aprotic solvent with high solubility and small dielectric constant;with the increase of TET concentration,the complexation rate increased rapidly and then decreased rapidly;as the mass ratio of phospholipid and TET increased,the complexation rate increasesd rapidly and then tended to flatten;with the increase of temperature,the complexation rate increased slowly and then decreased slowly,but decreased significantly when the temperature was 60?;with the increase of time,the complexation rate first increased rapidly and then tended to flatten.On the basis of single factor investigation,the mass ratio of phospholipid and TET,TET concentration and time were determined as the main factors affecting the complexation rate,the central composite design-response surface methodology was used to optimize the preparation process of TET-PLC,the optimal preparation process after optimization was as follows:phospholipid and TET were dissolved into an appropriate amount of ethyl acetate according to the mass ratio of4.5:1,the concentration of TET was 2.2 mg/m L,and the stir in the dark was carried out in the 30?constant temperature water bath for 3.25 h,the crude products of TET-PLC were obtained after removing ethyl acetate by rotary evaporation;the crude products of TET-PLC were dispersed to an appropriate amount of petroleum ether,which was fully dissolved by ultrasound,filtered with 0.45?m organic microporous membrane,and then the filtrate was rotationally evaporated and dried to get TET-PLC.The results of six verification experiments showed that the selected preparation process was reliable and stable,and the average complexation rate of TET-PLC was 92.71%.3.The structure of TET-PLC was characterized by SEM,XRD,FT-IR and ~1H-NMR,and its formation mechanism was discussed.The characterization results of SEM and XRD showed that TET-PLC showed similar amorphous characteristics of phospholipid;FT-IR characterization results showed that TET-PLC was the result of interaction between the polarity part of phospholipid and TET;the characterization results of ~1H-NMR showed that TET-PLC was not a new compound,but a complex formed by the intermolecular force between TET and phospholipid.The solubility of TET-PLC in water(25?)was 4.58 times that of TET,while the solubility of the physical mixture of TET and phospholipid in water(25?)was only 1.82 times that of TET,indicating that the significant improvement of the solubility of TET in TET-PLC was mainly due to the formation of phospholipid complex rather than the separate phospholipid solubilization.Preliminary stability test investigation results showed that the stability of TET-PLC was poor under high temperature,strong light and high humidity,it should be stored in low temperature and dry place away from light.4.A high performance liquid chromatography analysis method was established to detect the content of TET in biological samples,and the results of methodological verification showed that the established method was stable and reliable,and could meet the requirements of biological sample content determination.In the pharmacokinetic study of TET-PLC,the plasma TET concentration were determined after gavaging the same dose of TET and TET-PLC to mice,and the main pharmacokinetic parameters of the two were compared,the results showed that the average area under the drug-time curve AUC(0??)of TET-PLC and TET were 83.519 and 28.277 mg/L*h,respectively,indicating that the preparation of TET as TET-PLC could improve the oral bioavailability of TET.At the same time,the content of TET in heart,liver,spleen,lung,kidney and brain tissues were compared after gavage administration of TET and TET-PLC in mice,the results showed that TET-PLC increased the content of TET in each tissue,which laid a good foundation for the future research of TET-PLC.