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a nutraceutical
(substance with associated heath benefits)
-
an antioxidant
from www.sigmaaldrich.com
-
a biomaterial used for microencapsulation
derived from cellulose and ethanol in the
presence of dehydrating agents OR alkali
cellulose and ethyl chloride
from www.sigmaaldrich.com
CoQ10 tends to
bunch together,
making it hard to
absorb in the
intestine.
Nanoencapsulation
- separates individual
molecules w/o
altering its function
- Increases
bioavailability in the
intestine
To determine physical properties of
coenzyme Q10-loaded ethyl cellulose
nanoparticles:
 Particle size
 % drug loading
 UV stability
 thermal stability
Langmuir, 2003, 19(22), 95049510.
SEM images of EC microspheres
For controlled release of a
pesticide, norfluazon
[Pest Management Science, 2001, 57: 688-694]
For microencapsulation of
aspirin, for drug delivery
application
[J. of Microencapsulation, 2001,18(2), 223-236]
Particle size
Thermal stability
% drug loading
Colloids and Surfaces A : Physicochemical and Engineering Aspects, 2002, 210 (1): 95-104.
coQ10 gives
Absorbance at 217-290 nm
Solvents: methanol, ethanol,
water ( mobile phase)
from www.boomer.org
Column: C18

Prepare nanoparticles by solvent-evaporation
method by Desgouilles [Langmuir,
2003,19(22), 9504-9510]
Vary the mass ratio of coQ10 to EC
(20, 40, 50, 60, 80%)

Characterization of nanoparticles
by Dynamic Light Scattering
scattering angle: 90°
Temperature: 25 °
Light Scattering facility at UNC Chapel Hill
Hydrodynamic mean diameter and
polydispersity, μ2/Γ2, will be calculated by
continuous method
by Scanning Transmission Electron Microscopy
Hitachi HD 2000 Scanning Transmission Electron Microscope Specifications
( at NCSU Engineering Graduate Research Center)
Capabilities
Brightfield,Darkfield, Difraction z-contrast
Accelerating
Voltage
Magnification
200 kV
SEI Resolution
2.4 Angstroms
2,000,000 X
from NCSU Analytical Instrumentation Facility website
Sample preparation:
-Freeze dry the particles
-Extract coQ10 with methylene chloride
-Dissolve further in ethanol
Quantitation of coQ10:
-Prepare calibration solutions of coQ10 in ethanol
From www.waters.com
-Compute for the amount of coQ10 in sample from peak area
Peak Area, microV sec
External calibration curve
-Plot peak areas vs concentrations of calibration solutions
1,000,000.00
y = 747,965x - 13,407
800,000.00
R2 = 0.998
600,000.00
400,000.00
200,000.00
0.00
0.50
1.00
Concentration, g/L
Sample calibration curve
% drug loading =
concentration from calibration curve, g/mL x mL of injected sample x dilution factor
x 100
mass of freeze-dried sample, g
1.50
Freeze dry the particles
Expose the particles to UV
( 320-400 nm)
Extract the coQ10
Analyze by HPLC
Chromatogram of coQ10 & degradation products
( from Michael Stiff, NCSU Crop Science Department)
Sample preparation: Freeze drying
Thermal scan:
Rate: 10° C per min
Range: -10 to 160° C
TA2010 Thermal Analyzer
(TA Instruments, New Castle, DE)
Compare Tg and DHfusion
for coQ10, EC and coQ10-EC particles
Experiment
Technique
Particle Size Distribution
DLS
STEM
Drug-loading Efficiency
HPLC
UV Stability
Thermal stability
DSC
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