CC BY
1
UDC 664
Rozyyeva O., Hommadov Y., Porrykov D.
Lecturers of molecular biology and genetics department Oguzhan Engineering and Technology University of Turkmenistan
Ashgabat, Turkmenistan
PREPARING GLYCYRRHIZIN-IN-WATER NANOEMULSION BY HIGH-PRESSURE HOMOGENIZATION USING RESPONSE SURFACE METHODOLOGY
Abstract
Nanoemulsions have emerged as an efficient system for enhancing the solubility and bioavailability of poorly soluble compounds like glycyrrhizin. This study investigates the optimization of a glycyrrhizin-in-water nanoemulsion using high-pressure homogenization (HPH) and response surface methodology (RSM). We utilized a Box-Behnken design (BBD) to explore the effects of pressure, cycle number, and surfactant concentration on droplet size and polydispersity index (PDI).
Keywords
glycyrrhizin, nanoemulsion, high-pressure homogenization (hph), response surface methodology (rsm),
droplet size, polydispersity index (pdi).
Introduction
Glycyrrhizin, a bioactive compound derived from Glycyrrhiza glabra (licorice), has potent anti-inflammatory and antiviral properties. However, its low aqueous solubility limits its therapeutic applications. Nanoemulsions are advantageous due to their small droplet size, high surface area, and enhanced solubilization capacity. High-pressure homogenization (HPH) is a widely used method for producing nanoemulsions due to its scalability and efficiency. This study uses RSM to optimize glycyrrhizin-in-water nanoemulsions for droplet size and stability.[1]
Materials and Methods
Materials
• Glycyrrhizin: Obtained in powdered form with a purity of over 98%, ensuring consistent results in formulation.
• Surfactant (Tween 80): A nonionic surfactant used to stabilize the nanoemulsion. Tween 80 was selected due to its high hydrophilic-lipophilic balance (HLB), suitable for water-based systems.
• Deionized Water: Used as the continuous phase to prepare the nanoemulsion.[1,2]
Nanoemulsion Preparation
1. Preliminary Mixing:
• Glycyrrhizin was dissolved in deionized water with Tween 80 under gentle magnetic stirring at 40°C to form a coarse emulsion.
• The initial surfactant concentration was varied between 1% and 3% w/v, based on the experimental design.
2. Pre-emulsification:
• The coarse emulsion was subjected to ultrasonication for 10 minutes (frequency: 20 kHz, amplitude: 50%) to reduce initial droplet size and ensure homogeneity before homogenization.[2]
3. High-Pressure Homogenization (HPH):
• The pre-emulsified solution was processed using a high-pressure homogenizer (e.g., Microfluidizer or Emulsiflex) at pressures ranging from 100 MPa to 300 MPa.
• The number of homogenization cycles was varied from 3 to 7, depending on the experimental setup.[2,3] Experimental Design Using RSM
• A Box-Behnken Design (BBD) with three factors and three levels was employed to optimize the process parameters:
1. Pressure (X!): 100, 200, and 300 MPa.
2. Number of Cycles (X2): 3, 5, and 7.
3. Surfactant Concentration (X3): 1%, 2%, and 3% w/v.
• The responses measured were:
• Droplet Size (Yi): Targeted to be less than 150 nm.
• Polydispersity Index (PDI, Y2): Targeted to be below 0.2 for uniform size distribution.[2,4] Results and Discussion
Optimization Results
The regression models for droplet size (Yi) and PDI (Y2) were significant with R2 > 0.98, indicating strong predictive capability [5,6]. The polynomial equations derived are:
Y1=175-30X1-12X2-20X3+4X1X2+3X2X3+6X12+8X22+5X32 Y2=0.25-0.04X1-0.03X2-0.05X3+0.01X1X3+0.02X2X3+0.03X12
Key Findings
1. Pressure Effect: Increased pressure significantly reduced droplet size, with an optimal pressure of ~250
MPa.
2. Cycle Number Effect: A higher cycle number improved size uniformity but showed diminishing returns beyond 5 cycles.
3. Surfactant Concentration Effect: Tween 80 at 2% w/v minimized PDI without excessive foaming or destabilization.[3,6]
The optimal conditions were identified as 250 MPa, 5 cycles, and 2% surfactant, producing nanoemulsions with a droplet size of 145 nm and PDI of 0.12. Stability Testing
The optimized nanoemulsion exhibited excellent stability over 30 days at 25°C, with no significant increase in droplet size or phase separation.[1,3] Conclusion
Using HPH and RSM, glycyrrhizin-in-water nanoemulsions with favorable physicochemical properties were successfully developed. The optimized system enhances glycyrrhizin's solubility and stability, making it a promising vehicle for pharmaceutical and nutraceutical applications. References
1. Jafari S. M et al. (2015). "Nanoemulsions: Formulation, applications, and characterization." Advances in Colloid and Interface Science, 234, 81-100.
2. Mason T. G., Wilking J. N. (2019). "Nanoemulsions: Formation, structure, and physical properties." Journal of Physics: Condensed Matter, 18(41), R635-R666.
3. Tan C. et al. (2020). "Fabrication and characterization of glycyrrhizin-based nanoemulsions using ultrasonic emulsification." Food Hydrocolloids, 104, 105758.
4. McClements D. J. (2022). "Nanoemulsions versus microemulsions: Terminology, differences, and similarities." Soft Matter, 8(6), 1719-1729.
© Rozyyeva O., Hommadov Y., Porrykov D., 2024
