| Selaginella doederleinii Hieron draws great interests because of its anticancer activity.It has been previously established that the main anti-cancer ingredients of Selaginella doederleinii Hieron are the total biflavonoids.Our preliminary studies indicated that total biflavonoids has low water solubility,slow and incomplete dissolution,and low bioavailability.Solid dispersion technology is an effective means to improve solubility and bioavailability.This project investigated the preparation of solid dispersions(SDs)of the total biflavonoids extract of Selaginella doederleinii Hieron.The SDs were amorphous.The SDs' flowability,solubility and other properties,as well as stability were investigated.The SDs were directly filled into capsules.The quality standard and stability of the solid dispersions capsules were established.In addition,the anticancer effect of the preparation was investigated in animal model.This project laid the foundation for the development of drug preparation of total biflavonoids extract of Selaginella doederleinii Hieron.The research contents and contributions of this paper were as follows:(1)Preparation of total biflavonoids SDsSolid dispersions of the total biflavonoids(total biflavonoids SDs)were prepared for the first time.PEG-6000,PEG-4000,F68 and PVP-K30 were tested as the carriers.SDs were prepared by solvent method and solvent-melting method.SDs prepared with PEG-6000,PEG-4000,and F68 were difficult to dry and process.SDs prepared with PVP-K30 had good processability and were selected for further studies.Optimal mass ratio of PVP-K30 to total biflavones was established via orthogonal experiment.In addition,the basic properties of the solid dispersion such as solubility,flowability,bulk density,stability in different solvents,oil-water partition coefficient,etc.were investigated.The final optimized process was as follow: weigh the total biflavonoids extract and PVP-K30 with a mass ratio of 1:5,dissolve them with appropriate amount of ethanol separately;the total biflavonoids extract solution was added dropwise into the PVP-K30 solution;ultrasonicate for 20 minutes to mix completely,then steam at 60 ? to remove the ethanol;vacuum dry at 50 ?,crush and sieve with 80 mesh sieve.Store the resultant SDs in a desiccator.The solubility of the total biflavonoids increased from87.22 ?g/mL in the total biflavonoids extract to 1.50 mg/mL in the solid dispersion.The data of DSC and infrared spectroscopy demonstrated that the solid dispersion was amorphous.(2)Preparation of Solid Dispersion Capsule and its Quality StandardThe angle of repose data indicated that the SDs had a good flowability.So the solid dispersions were directly filled into capsules.The solid dispersion capsules were then subjected to quality study,including traits,identification(by UV absorption spectrum and HPLC),water content,dissolution,and assay(by UV absorption method to determine the content of total biflavonoids,by HPLC method to determine the content of Delicaflavone,one of the main constituents of the total biflavonoids)and so on.In addition,the stability of solid dispersion capsules was investigated under accelerated conditions.A method for the analysis of moisture content,and a dissolution method were developed in line with the Pharmacopoeial requirements.The HPLC method for the analysis of Delicaflavone content was precise,accurate and reproducible.The content and dissolution of total biflavonoids were determined by UV absorption,which was accurate,reliable and user-friendly.The results of stability experiments showed that total biflavonoids SD capsules were stable under the studied conditions of light,high temperature,high humidity and the ICH accelerated stability conditions(40 °C/75 % RH).(3)In vivo Pharmacodynamics Studies of SD CapsulesThe in vivo pharmacodynamics of the total biflavonoids SD Capasules were investigated by human lung cancer A549 cell tumors bearing nude mice model.The effects of the preparation on the volume,weight and microvessel density of A549 transplanted tumor were observed with low,middle,and high doses.The results showed that the tumor inhibition of total biflavonoids SDs was dose-dependent.The high dose group had the best effect with an inhibition rate was 59 %;the inhibitory rate of the middle dose group was 52 %(P<0.05),which was comparable to that of the positive control group(doxorubicin).The inhibitory rate of the low dose group was 28 %(P<0.05).And there was a significant difference between the middle dose group and the negative control group(P<0.05).Tumor necrosis was observed in high and middle dose groups in the HE staining experiment.The results of CD34 blood vessel density showed that the microvessel density of tumor tissue was down-regulated in a dose-dependent manner.Compared with the negative group,high dose and medium dose were significantly different(P<0.05).In summary,the total biflavonoids SDs were prepared successfully,and its solubility and dissolution were significantly improved.The prepared SDs had a good flowability and were suitable for direct filling preparation of capsules.The quality standard was established and the stability study showed that the total biflavonoids SDs were stable.In addition,the prepared total biflavonoids SDs demonstrated good in vivo anti-tumor effects.This study laid the foundation for the development of the total biflavonoids anticancer drugs from Selaginella doederleinii Hieron... |
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