Characterization of Coenzyme Q10-loaded Ethyl Cellulose Nanoparticles

using HPLC, Dynamic Light Scattering,

Electron Microscopy and DSC

- a nutraceutical

(substance with associated heath

benefits)- an antioxidant

Coenzyme Q10

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

Ethyl cellulose

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

Nanoencapsulation of coQ10

To determine physical properties of coenzyme Q10-loaded ethyl cellulose

nanoparticles: Particle size % drug loading UV stability thermal stability

Objective

Presupposition from Literature:

Nanoparticles of ethyl cellulose can be prepared by solvent-evaporation

Langmuir, 2003, 19(22), 9504-9510.

SEM images of EC microspheres

Presupposition from Literature:

Ethyl cellulose (EC) is used as a biomaterial

media for encapsulation

For microencapsulation of aspirin, for drug delivery application [J. of Microencapsulation, 2001,18(2), 223-236]

For controlled release of a pesticide, norfluazon [Pest Management Science, 2001, 57: 688-694]

Presupposition from Literature:

Coenzyme Q10 - loaded PMMA

were characterized usingTEM, Dynamic light scattering,DSC, HPLC, NMRto determine

Particle size Thermal stability % drug loading

Colloids and Surfaces A : Physicochemical and Engineering Aspects, 2002, 210 (1): 95-104.

Presupposition from Literature:

HPLC is a reliable method for quantitative analysis of CoQ10

coQ10 gives

Absorbance at 217-290 nm

Solvents: methanol, ethanol, water ( mobile phase)

Column: C18 from www.boomer.org

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

Methods

by Dynamic Light Scattering

scattering angle: 90° Temperature: 25 °

Hydrodynamic mean diameter and polydispersity, μ2/Γ

2, will be calculated by continuous method

Measurement of Particle Size Distribution

                           

Light Scattering facility at UNC Chapel Hill

Measurement of Particle Size Distribution

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

200 kV

Magnification 2,000,000 X

SEI Resolution 2.4 Angstroms

from NCSU Analytical Instrumentation Facility website

Sample preparation:-Freeze dry the particles-Extract coQ10 with methylene chloride-Dissolve further in ethanol

Drug-loading efficiency determination of coQ10 by HPLC

concentration from calibration curve, g/mL x mL of injected sample x dilution factor% drug loading = 100

mass of freeze-dried sample, gx

Quantitation of coQ10:

-Prepare calibration solutions of coQ10 in ethanol

-Plot peak areas vs concentrations of calibration solutions

-Compute for the amount of coQ10 in sample from peak area

                                                                             

From www.waters.com

External calibration curve

y = 747,965x - 13,407

R2 = 0.998

-

200,000.00

400,000.00

600,000.00

800,000.00

1,000,000.00

0.00 0.50 1.00 1.50

Concentration, g/L

Pea

k A

rea,

mic

roV

sec

Sample calibration curve

Freeze dry the particles

Expose the particles to UV ( 320-400 nm)

Extract the coQ10

Analyze by HPLC

Measurement of UV stability of coQ10 by HPLC

Chromatogram of coQ10 & degradation products

( from Michael Stiff, NCSU Crop Science Department)

Measurement of thermal stability by DSC

Compare Tg and DHfusion

for coQ10, EC and coQ10-EC particles

TA2010 Thermal Analyzer(TA Instruments, New Castle, DE)

Sample preparation: Freeze drying

Thermal scan:

Rate: 10° C per min

Range: -10 to 160° C

Characterization methods of coQ10-loaded EC nanoparticles

Experiment Technique

Particle Size Distribution DLS STEM

Drug-loading Efficiency HPLC 

UV Stability

Thermal stability DSC