This document describes the validation of an assay method to quantify ibuprofen using UV spectroscopy. The method was validated for specificity, linearity, range, precision, and accuracy. Specificity was demonstrated through distinct spectra of pure ibuprofen and ibuprofen in a matrix. Linearity was shown from 1-25 μg/ml with an R2 value of 0.9997. Assay precision had a relative standard deviation of 0.37-1.61% and accuracy studies showed % recovery from 99.76-102.4%. In conclusion, the UV spectroscopic method was validated and demonstrated good accuracy and precision for quantifying ibuprofen.

1. VALIDATION OF ASSAY
METHOD OF IBUPROFEN BY
UV SPECTROSCOPY
PRESENTED BY :
TANMOY DAS
B.PHARM
SEM-7
NETAJI SUBHAS CHANDRA BOSE INSTITUTE
OF PHARMACY
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2. CONTENT
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3. VALIDATION
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4. ASSAY
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5. IBUPROFEN
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C COOH
CH3
H
CHCH2
H3C
H3C
Molecular formula1 C13H18O2.
Molecular Weight 206.28 g/mol
Melting Range 75 to 780C
Solubility Freely soluble in acetone, chloroform, ethanol (95%) and ether, practically insoluble in water, it
dissolves in dilute solution of alkali hydroxide, carbonates
Apparent pKa 5.2

6. PHOSPHATE BUFFER
SOLUTION(PBS),PH-7.2
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0
0.1
0.2
0.3
0.4
0.5
0.6
240 260 280 300 320 340 360 380 400
UVAbsorbance
Wavelength (nm)
UV spectrum of Ibuprofen in PBS pH 7.2 ,concentration 20.0 micg/ml
Drug

7. SPECIFICITY
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0
0.1
0.2
0.3
0.4
0.5
0.6
240 260 280 300 320 340 360 380 400
UVAbsorbance
Wavelength (nm)
UV spectrum of pure Ibuprofen and Ibuprofen matrix
Drug Drug+Matrix

8. LINEARITY
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1
2
5
10
15
20
25
y = 28.87x - 0.1486
R² = 0.9997
0
5
10
15
20
25
30
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Conc(mg/ml)
Abs (221nm)
Standard straight line of Ibuprofen in PBS pH 7.2 at
264nm
Conc (micg/ml) Abs (264nm)
1 0.0346
2 0.0791
5 0.1828
10 0.3467
15 0.5285
20 0.6913
25 0.8748
Slope = 28.8700
Intercept = – 0.1486

9. RANGE
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00.51
2
5
10
15
20
25
30y = 27.39x + 0.2035
R² = 0.9967
0
5
10
15
20
25
30
35
0 0.2 0.4 0.6 0.8 1 1.2
Conc(micg/ml)
Abs (221nm)
Standard straight line of Ibuprofen in PBS pH 7.2 at 264nm
for testing the range
Conc (micg/ml) Abs (264nm)
0.5 0.0123
1 0.0346
2 0.0791
5 0.1828
10 0.3467
15 0.5285
20 0.6913
25 0.8748
30 1.1369

10. PREECISION
Conc. of pure drug added
(mg/ml)
Conc. of drug obtained by
assay
(mg/ml)
Mean SD
RSD
(%)
SEM
1 0.0352
0.0342 0.00140 4.09 0.00081 0.0348
1 0.0326
10 0.3482
0.3532 0.00569 1.61 0.003310 0.3521
10 0.3594
25 0.8762
0.8738 0.00325 0.37 0.001925 0.8751
25 0.8701
10/13𝑅𝑆𝐷 =
𝑆𝐷
𝑀𝑒𝑎𝑛
𝑥100% and 𝑆𝐸𝑀 =
𝑆𝐷
𝑛
where n = 3.

11. ACCURACY
Solution Vol. of Soln. A
(mL)
Vol. of Soln. B
(mL)
Distilled Water
(mL)
Final conc.
Approx. (g/ml)
Conc. After assay
(g/ml)
S1 0.1 0.1 9.8 1 C1
S2 1.0 1.0 8.0 10 C2
S3 2.5 2.5 5.0 25 C3
S4 0.1 0.0 9.9 0.5 C4
S5 1.0 0.0 9.0 5 C5
S6 2.5 0.0 7.5 12.5 C6
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𝑅𝑒𝑐𝑜𝑣𝑒𝑟𝑦 𝑓𝑜𝑟 𝑆1 & 𝑆4 =
𝐶1 − 𝐶4
0.5
𝑥100%
𝑅𝑒𝑐𝑜𝑣𝑒𝑟𝑦 𝑓𝑜𝑟 𝑆2 & 𝑆5 =
𝐶2 − 𝐶5
5.0
𝑥100%
𝑅𝑒𝑐𝑜𝑣𝑒𝑟𝑦 𝑓𝑜𝑟 𝑆3 & 𝑆6 =
𝐶3 − 𝐶6
12.5
𝑥100%

12. Conc. of pure drug added
(mg/ml)
Conc. of drug obtained by assay
(mg/ml)
% Recovery Mean SD
RSD
(%)
0.5 0.508
101.60
101.53 0.90 0.890.5 0.512
102.40
0.5 0.503
100.60
5 5.039
100.78
100.32 0.52 0.525 4.988
99.76
5 5.021
100.42
12.5 12.511
100.09
99.99 0.09 0.0912.5 12.496
99.97
12.5 12.489
99.91
Overall 100.61 0.88 0.87
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Determination of Accuracy of the assay method
The overall % recovery was found to be 100.61 and the RSD of 0.87%. Therefore, the proposed assay
method has good accuracy within the range of 1 to 25 gml.

13. CONCLUSION
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