The Study Of Self-microemulsified Drug Delivery Systems Of Trifolirhizin Based On Drug-phospholipid Complex Technique

More and more components have been found effective but low solubility which brings great difficulties to clinical application.Trifolirhizin is separated from Sophora flavonoids,which has a higher content of flavonoid constituents.Pharmacological research have indicated that the trifolirhizin has a significant anti-inflammatory effect,anti-fungal activity[1-2],liver protection,anti-cancer,anti-platelet gather effects and estrogenic effects[3-5].However,the study found that trifolirhizin was difficult dissolved in both water and oil that result in low oral bioavailability,seriously limited the development of trifolirhizin,which belongs to the biopharmaceutics drug class IV.This work aims to research the physical and chemical properties of trifolirhizin,then prepared self-microemulsifying technique based on phospholipid complex in order to solve the badly solubility and permeability to improve the bioavailability.Specific studies are shown in below:1 Study of of trifolirhizin prescriptionEstablished the content of trifolirhizin analysis method by the HPLC method,linear regression equation is:A=8E+06x-37028,r2=0.9998,the linear range from 0.031 to 0.31mg/ml.The equilibrium solubility method was used to determine the saturation solubility of trifolirhizin in water and different pH phosphate buffer.The results indicated that the average solubility of trifolirhizin was 0.035mg/ml.Shake flask method was employed to test the oil/water partition coefficient of trifolirhizin in pH 1.2,7,7.4,the results showed that lgPapp were 0.2528,0.2923,0.2742,which indicated that trifolirhizin was poor solubility.2 Trifolirhizin phospholipid complex(TPC)preparation and characterizationAcetone was screened as the best reaction solvent at temperature 40? with single factor.According to the L 9(34)orthogonal experimental range to investigate ratio of drug in phospholipid(A),reactant concentration(B),reaction time(C)effects on composite percentage and variance analysis results,finally the preferred preparation process recipe is:reactant concentration is 4mg/ml,the drug and phospholipid ratio 1:1.5(w/w),the reaction time is 3h.The morphology phospholipid complex under the transmission electron microscope are spherical or near spherical.UV,FT-IR,DSC were used to forecast the mechanism of action between trifolirhizin and phospholipids to prove the formation of TPC.UV spectra shows that chromophore structure of trifolirhizin has not changed,suggesting that there is no chemical reaction between trifolirhizin and lecithin;TPC FT-IR spectra of-OH peak was blue shift from 3300.8 cm-1 to 3373.4cm-1,presumably due to the steric effect result in the interaction between-OH of trifolirhizin and the quaternary ammonium charge of phospholipid;DSC analysis showed that the phase transition temperature of trifolirhizin phospholipid complex endothermic peak was decreased,which may be due to hydrogen bonding association between trifolirhizin and phospholipids,thus forming different peak from trifolirhizin and phospholipid.These results showed that the formation of trifolirhizin and phospholipid is different from compounds in physical mixing,i.e.phospholipid complex.3 Trifolirhizin phospholipid complex self microemulsion(TPC-SMEDDS)preparation and characterizationFirst of all,the solubility of TPC in various vehicles was determined by HPLC method to screen the vehicles.Secondly,TPC-SMEDDS formulation and dosage range were determined by the intermiscibility experiments,self-emulsifying efficiency tests and ternary phase diagram.Central composite design and response surface optimization was used to optimize the prescription.The emulsion droplet size,PDI,drug loading was evaluated to study the factors of X1 = oil weight percent and X2= emulsifier and auxiliary emulsifier ratio.The prediction of optimal prescription is:Capryol 90 43.65%,Cremophor EL40:Transcolt HP= 7.58,the drug loading was 20mg,PDI was 0.066,the droplet size was 24nm.The optimized formulation could rapid dispersion in vitro with emulsion droplet size 24.84±0.40nm and zeta potential-15.42±0.62mv;Observed TPC-SMEDDS morphology by transmission electron microscope are spherical distribution uniform;Stability reaserch indicated the appearance,particle size and zeta potential were didn't obviously change within 2 months that good for the stability of the microemulsion;In vitro release test showed that more than 95%trifolirhizin was released within 10min of TPC-SMEDDS,19 times as much as the bulk drug and the dissolution rate increased obviously.4 Transport experiments of Tri,TPC,TPC-SMEDDS in Caco-2 cellsHPLC method was used to determine the content of trifolirhizin.Tri,TPC,TPC-SMEDDS transport in Caco-2 cells were studied,the experimental results showed that the volume of trifolirhizin through AP side to BL side after added 3h is only 0.13 ?g,while TPC and TPC-SMEDDS were respectively 2.12?g and 9.14?g;Ttrifolirhizin accumulate release rate of trifolirhizin was only 0.65%,most of the trifolirhizin were left in the AP side,indicating that trifolirhizin is hardly to absorb,speculated that the body can not easily be intestinal absorption.However,the accumulate release rate of TPC and TPC-SMEDDS were respectively 10.6%and 45.69%.Presumably that phospholipid complex self microemulsion can significantly improve trifolirhizin absorption.5 Study on the pharmacokinetics of,Tri,TPC,TPC-SMEDDS in ratsHPLC method was established to determine the trifolirhizin in rat plasma,the linear regression equation is Y=20061X-27726,r2=0.9988,linear range of 0.05-100?g/ml.Rats were gavaged by Tri,TPC,TPC-SMEDDS,at the scheduled time orbital blood 0.4ml.Drug in plasma samples were extracted with methanol to precipitate protein.DAS2.0 processed parameters of pharmacokinetics.The results showed that the Tri suspension,the solution of TPC and TPC-SMEDDS drug process are in line with the kinetic characteristics of one compartment model.Under the condition of same dose,compared with the material medicine,Cmax and AUC of TPC-SMEDDS in rat were increased by 5.11 times and 3.88 times,respectively.The results given that prepared phospholipid complex self microemulsion can significantly increase the area under the curve and promote the absorption of the drug to enhance bioavailability of trifolirhizin.