Background: The objective of this study was to make colloidal dispersions of the active compounds of radix of Angelica gigas Nakai that could be charaterized as nano-composites using hot melt extrusion (HME). Food grade hydrophilic polymer matrices were used to disperse these compound in aqueous media.
Methods and Results: Extrudate solid formulations (ESFs) mediated by various HPMCs (hydroxypropyl methylcelluloses) and Na-Alg polymers made from ultrafine powder of the radix of Angelica gigas Nakai were developed through a physical crosslink method (HME) using an ionization agent (treatment with acetic acid) and different food grade polymers [HPMCs, such as HP55, CN40H, AN6 and sodium alignate (Na-Alg)]. X-ray powder diffraction (XRD) analysis confirmed the amorphization of crystal compounds in the HP55-mediated extrudate solid formulation (HP55-ESF). Differential scanning calorimetry (DSC) analysis indicated a lower enthalpy (ΔH = 10.62 J/g) of glass transition temperature (Tg) in the HP55-ESF than in the other formulations. Infrared fourier transform spectroscopy (FT-IR) revealed that new functional groups were produced in the HP55-ESF. The content of phenolic compounds, flavonoid (including decursin and decursinol angelate) content, and antioxidant activity increased by 5, 10, and 2 times in the HP55-ESF, respectively. The production of water soluble (61.5%) nano-sized (323 ㎚) particles was achieved in the HP55-ESF.
Conclusions: Nano-composites were developed herein utilizing melt-extruded solid dispersion technology, including food grade polymer enhanced nano dispersion (< 500 ㎚) of active compounds from the radix of Angelica gigas Nakai with enhanced solubility and bioavailability. These nano-composites of the radix of Angelica gigas Nakai can be developed and marketed as products with high therapeutic performance.

ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
  1. Chemical and reagents
  2. Preparation of ultrafine powder of radix of A.gigas Nakai
  3. Solid formulation of ultrafine powder of radix ofA. gigas Nakai with polymers using HME
  4. Particle size analysis
  5. Solubility measurements
  6. Infrared Fourier transform spectroscopy (FT-IR)analysis
  7. Differential scanning calorimetry (DSC) analysis
  8. X-ray powder diffraction (XRPD) analysis
  9. Extractions
  10. Determination of total phenolic contents (TPC)
  11. Determination of total flavonoid conten (TF)
  12. DPPH free radical scavenging activity
  13. HPLC analysis of decursin and decursinol angelate
  14. Statistical analysis
 RESULTS AND DISCUSSION
  1. Physical-chemical characteristics of extrudate solidformulations (ESFs) mediated various HPMCs and Na-Alg polymer
  2. Analytical investigation of extrudate solid formulations(ESFs) mediated various HPMCs and Na-Alg polymer
  3. Nano-composite by solid formulations (ESFs)mediated various HPMCs and Na-Alg polymer
 REFERENCES

• Md Obyedul Kalam Azad(강원대학교 생명건강공학과)
• 조현종(강원대학교 약학과) | Hyun Jong Cho (Department of Pharmacy, Kangwon National University)
• 임정대(강원대학교 생약자원개발학과) | Jung Dae Lim (Department of Herbal Medicine Resource, Kangwon National University)
• 강위수(강원대학교 생명건강공학과) | Wie Soo Kang (Department of Bio-Health Technology, Kangwon National University) Corresponding author