Background: The root of Angelica gigas Nakai is used as a traditional herbal medicine in Korea for the treatment of many diseases. However, the poor water solubility of the active components in A. gigas Nakai is a major obstacle to its bioavailability.
Methods and Results: This work aimed at enhancing the solubility of the active compounds of A. gigas Nakai by a chemical (using a surfactant) and physical (hot melt extrusion, HME) crosslinking method. Fourier transform infrared spectroscopy revealed multiple peaks in the case of the extrudate solids, attributable to new functional groups including carboxylic acid, alkynes, and benzene derivatives. Differential scanning calorimetry analysis showed that the extrudate soilid had a lower glass transition temperature (Tg) and enthalpy (ΔH) (Tg : 43℃, ΔH : < 6 J/g) as compared to the non-extrudate (Tg : 68.5℃, ΔH : 123.2) formulations. X-ray powder diffraction analysis revealed the amorphization of crystalline materials in the extrudate solid. In addition, enhanced solubility (53%), nanonization (403 ㎚), and a higher amount of extracted phenolic compounds were achieved in the extrudate solid than in the non-extrudate (solubility : 36%, nanonization : 1,499 ㎚) formulation. Among the different extrudates, acetic acid and span 80 mediated formulations showed superior extractions efficiency.
Conclusions: HME successfully enhanced the production of amorphous nano dispersions of phenolic compound including decursin from extrudate solid formulations.

ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
  1. Chemical and reagents
  2. Preparation of ultrafine powder of AGR (UFP-AGR)
  3. Preparation of chemical formulation
  4. Preparation of extrudate formulation and HMEconfiguration
  5. Particle size analysis
  6. Solubility measurements
  7. Evaluation of amorpous solid dispersion by FT-IR,DSC, and XRPD
  8. Extraction of formulation
  9. Determination of total phenolic contents (TP)
  10. Determination of total flavonoid content
  11. DPPH free radical scavenging activity
 RESULTS AND DISCUSSION
  1. Particle size reduction and solubility enhancement
  2. FT-IR, DSC and XRD analysis of extrudate solidformuation of Angelica gigantis radix ultrafine powderwith chemical formulation.
  3. Total phenol content, total flavonoid content,DPPH radical scavenging activity and contents ofactive compounds in extrudate solid formuation ofAngelica gigantis radix ultrafine powder with chemicalformulation.
 ACKNOWLEDGEMENTS
 REFERENCES

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