Preparation and quality evaluation of total flavonoids microemulsion of "Pueraria lobata-Hovenia dulcis" / 中国中药杂志

The effective components of flavonoids in the "Pueraria lobata-Hovenia dulcis" drug pair have low bioavailability in vivo due to their unstable characteristics. This study used microemulsions with amphoteric carrier properties to solve this problem. The study drew pseudo-ternary phase diagrams through titration compatibility experiments of the oil phase with emulsifiers and co-emulsifiers and screened the prescription composition of blank microemulsions. The study used average particle size and PDI as evaluation indicators, and the central composite design-response surface method(CCD-RSM) was used to optimize the prescription; high-dosage drug-loaded microemulsions were obtained, and their physicochemical properties, appearance, and stability were evaluated. The results showed that when ethyl butyrate was used as the oil phase, polysorbate 80(tween 80) as the surfactant, and anhydrous ethanol as the cosurfactant, the maximum microemulsion area was obtained. When the difference in results was small, K_(m )of 1∶4 was chosen to ensure the safety of the prescription. The prescription composition optimized by the CCD-RSM was ethyl butyrate(16.28%), tween 80(9.59%), and anhydrous ethanol(38.34%). When the dosage reached 3% of the system mass, the total flavonoid microemulsion prepared had a clear and transparent appearance, with average particle size, PDI, and potential of(74.25±1.58)nm, 0.277±0.043, and(-0.08±0.07) mV, respectively. The microemulsion was spherical and evenly distributed under transmission electron microscopy. The centrifugal stability and temperature stability were good, and there was no layering or demulsification phenomenon, which significantly improved the in vitro dissolution of total flavonoids.

Optimization of preparation of lignum dalbergia odorifera oil-hydroxyl-β-cyclodextrin inclusion complex by central composite design-response surface method / 中国药学杂志

OBJECTIVE: To prepare the inclusion complex of Lignum dalbergia odorifera oil with hydroxyl-β-cyclodextrin (HP-β-CD), and to optimize the preparation process of it. METHODS: The inclusion complex was prepared by the stirring-freeze-dry meth od. The preparation process was optimized by central composite design-response surface method (CCD-RSM), with the colligation score which was calculated by the yield of inclusion, the utilization rate of volatile oil and the content of trans-nerolidol as index. The inclu sion complex was verified by phase-solubility method, DSC,UV and microscopical identification. RESULTS: The optimum inclusion technology was: inclusion solvent 5% ethanol, stirring rate 500 r·min-1, HP-β-CD to volatile oil 33:1, inclusion temperature 42℃, inclusion time 2.5 h. The formation of inclusion complex can change the solubility, optical and thermodynamic properties of volatile oil. CONCLUSION: The preparation process of inclusion complex of Lignum dalbergia odorifera oil with HP-β-CD optimized by CCD-RSM is reasonable and feasible, and provide a reliable experiment basis for its application.