Development of UV Spectrophotometric method of Idebenone in ...

Asian J. Research Chem. 2(2): April.-June, 2009
,
Preparation of sample solution:
The proposed method was applied to analyse commercially
available Idebenone tablet. Ten tablets were weighed and
powdered. The amount of tablet powder equivalent to 10
mg of Idebenone was weighed accurately and transfer to
100ml volumetric flask then 20 ml absolute ethanol was
added and kept for 15 min with frequent shaking and
volume was made up to mark with phosphate buffer pH
6.8.The solution was then filtered through Whattman filter
paper #41.This filtrate was diluted suitably with solvent
(20% v/v absolute ethanol in phosphate buffer pH 6.8) to
get the solution of 12µg/ml concentration .The absorbance
was measured against solution blank.
Table No.1 - Calibration Curve parameter
Sr.
No.
Concentration
(µg/ml)
Absorbance
(average)
Standard
deviation
1 0 0 0
2 2 0.0713 ±0.005859
3 4 0.1552 ±0.001724
4 6 0.2552 ±0.0009
5 8 0.3629 ±0.001206
6 10 0.4766 ±0.014856
7 12 0.5577 0
8 14 0.6332 ±0.010201
9 16 0.7384 ±0.006341
10 18 0.8584 ±0.009174
11 20 0.9651 ±0.007279
Table.2 - Validation parameters
Sr. No. Parameter
Result
1. Absorption maxima(nm) 282
2. Linearity Range (µg/ml) 4-20
3 Standard Regression y = 0.0485x - 0.0239
Equation
4 Correlation Coefficient (r2 ) r 2 = 0. 9978
5 Molar absorptivity 14818.71
6 A( 1% , 1cm ) 443.088
7 Accuracy (% recovery ±SD) 99.74 % ± 0.07211
8 Precision (% CV) 99.67 %, 99.68 %
9 Specificity A 12 µg/ml solution
of candidate drug in
solvent (20%v/v
ethanol in 6.8-pH
phosphate buffer) at
UV detection λ of
282 nm will show an
absorbance value of
0.5777
10 Sandell’s Sensitivity 8 0.022735
(µg/cm 2 /0.001 absorbance
unit)
11 LOD (µg/ml) 1.6261
12 LOQ (µg/ml) 4.9278
The drug content of the preparation was calculated using
standard calibration curve. Amount of drug estimated by
this method is given in (Table No.3).
RESULT AND DISCUSSION:
Precision:
Assay of method precision (intra-day precision) was
evaluated by carrying out six independent assays of test
samples of Idebenone. The intermediate precision (interday
precision) of the method was also evaluated using
two different analysts, systems and different days in the
same laboratory. The relative standard deviation (RSD)
and assay values obtained by two analysts were 0.28,
99.67 and 0.26, 99.68 respectively (Table no.4).
Fig. No.1 - Chemical structure of Idebenone
O
MeO
MeO
O
CH 3
Accuracy (Recovery Test) 7 :
Accuracy of the method was studied by recovery
experiments. The recovery experiments were performed
by adding known amounts of the drugs in the placebo.
The recovery was performed at three levels, 80,100and
120% of Idebenone standard concentration. The
recovery samples were prepared in afore mentioned
procedure. Three samples were prepared for each
recovery level. The solutions were then analyzed, and
the percentage recoveries were calculated from the
calibration curve. The recovery values for Idebenone
ranged from 99.68 to 99.82 % (Table no.3).
Fig. No.2 - Determination of max of Idebenone by UV
scanning.
282 nm
1.4
1
Abs
0.5
OH
-0.1
200 250 300 350 400
Wavelength [nm]
Linearity:
The linearity of the response of the drug was verified at
2 to 40 g/ml concentrations, but linearity was found to
be between 4-20 g/ml concentrations. The calibration
curve was obtained by plotting the absorbance versus the
concentration data and was treated by linear regression
analysis (Table no.2). The equation of the calibration
curve for Idebenone obtained was y = 0.0485x - 0.0239,
the calibration curve was found to be linear in the
aforementioned concentrations (The correlation
coefficient (r 2 ) of determination was 0.9978).
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