International Journal of PharmTech Research

CODEN (USA): IJPRIF

ISSN : 0974-4304
Vol.2, No.2, pp 1119-1123,
April-June 2010

Simultaneous Estimation of
Tramadol Hydrochloride and Paracetamol by UV
Spectrophotometric Method from Tablet Formulation
Deepali Gharge*, Pandurang Dhabale
Government College of Pharmacy, Karad, Dist Satara-415124, M.S., India.

*Corres.author : deepali_gharge@rediffmail.com
Abstract: A simple, accurate, precise and economical procedure for simultaneous estimation of tramadol
hydrochloride and paracetamol in two component tablet dosage form has been developed utilizing concept of internal
standard addition. The method is based upon determination of tramadol hydrochloride at 270.5 nm and paracetamol at
243.5 nm, in distilled water. Tramadol hydrochloride and paracetamol at their respective max 270.5 nm and 243.5 nm
shows linearity in the concentration range of 20-100 g/ml and 3-15 g/ml respectively. The method was validated
statistically. Recovery study was performed to confirm the accuracy of the method.
Key Words: Tramadol hydrochloride, Paracetamol, Simultaneous equation method, Area under curve method,
Recovery study.

Introduction And Experimental

Tramadol hydrochloride is a centrally acting analgesic,
used for treating moderate to severe pain. Tramadol
hydrochloride possesses agonist actions at the -opioid
receptor and effects reuptake at the noradrenergic and
serotonergic systems. Tramadol is a compound with agonist
activity.
Chemically
it
is
[2(dimethylaminomethyl)-1-(3methoxyphenyl)cyclohexanol]. It is used to treat
moderate to moderately severe pain and most types of
neuralgia, including trigeminal neuralgia. Paracetamol
is official in Indian Pharmacopoeia and British
Pharmacopoeia. [16] The I.P. & B.P. both suggest
titrimetric and UV spectrophotometric assay method
for paracetamol in bulk and tablet formulations.
Tramadol is available in the form of oral drops, tablets,
capsules and injections[1]. There are various methods
available for estimation of tramadol hydrochloride like
UV spectrophotometric[2,3], spectrofluorometry[4],
HPLC[5] , gas chromatography[6], GC-MS and LCMS[7], capillary electrophoresis[8], HPTLC[9],
HPTLC-densitometry, [10,11] etc. Paracetamol
estimated simultaneously with other drugs by UV and
RP-HPLC methods. [13, 14, 15] [However some of
these methods are costlier and time consuming. To
overcome these difficulties spectrophotometric

analysis serves to be the quickest, promising and

reliable method for routine analytical needs. The aim
of the present study is to develop a new simple, rapid,
reliable and precise UV spectrophotometric method for
analysis of tramadol from tablet formulation; method
is based on measurement of UV absorbance of
tramadol hydrochloride in methanol diluted with
distilled water.

Apparatus:
Spectral runs were made on a Shimadzu UV-Visible
spectrophotometer, model- 1700 (Japan) was
employed with spectral bandwidth of 1 nm and
wavelength accuracy of 0.3 nm with automatic
wavelength corrections with a pair of 10 mm quartz
cells. Glasswares used in each procedure were soaked
overnight in a mixture of chromic acid and sulphuric
acid rinsed thoroughly with double distilled water and
dried in hot air oven.
Reagents and Solution:
All the reagents used in this assay were of analytical
grade and the reagent solutions were prepared using
preanalysed distilled water. Tramadol and Paracetamol
pure drugs were obtained as a gift sample from Aristo
Pharmaceuticals Limited, Mumbai. Tablets of

Deepali Gharge et al /Int.J. PharmTech Res.2010,2(2)

tramadol hydrochloride and paracetamol combined

dosage form were purchased from local market for
analysis. Distilled water was used as a solvent for the
spectrophotometric estimation.
Determination of max:
Weighed an accurate amount 10mg of tramadol
hydrochloride was dissolved in 20ml distilled water
and diluted upto 100ml by distilled water to obtain a
100mcg/ml concentration of tramadol hydrochloride in
solution. Weighed an accurate amount 10mg of
paracetamol was dissolved in 20ml distilled water and
diluted upto 100ml by distilled water to obtain a
100mcg/ml concentration of paracetamol. This
solutions was subjected to scanning between 200 400
nm and absorption maxima at 270.5 nm and 243.5nm
for tramadol hydrochloride and paracetamol
respectively were determined.
Standard Stock Solution:
A stock solution containing 100mcg/ml of pure drugs
were prepared by dissolving accurately weighed an
accurate amount 10mg of tramadol hydrochloride was
dissolved in 20ml distilled water and diluted upto
100ml by distilled water to obtain a 100mcg/ml
concentration of tramadol hydrochloride in solution.
Weighed an accurate amount 10mg of paracetamol
was dissolved in 20ml distilled water and diluted upto
100ml by distilled water to obtain a 100mcg/ml
concentration of paracetamol.
Working standard solution:
Stock solutions were as such used as working standard
solutions.
Linearity and Calibration:
The aliquots working standard solution was diluted
serially with sufficient distilled water to obtain the
concentration range of 20 100 mcg/ml for tramadol
hydrochloride and 3 15mcg/ml for paracetamol. A
calibration curve for tramadol and paracetamol were
obtained by measuring the absorbance at the max of
270.5 nm and 243.5nm respectively and vise-versa.
And the following equations are set. Statistical
parameters like the slope, intercept, coefficient of
correlation, standard deviation, relative standard
deviation, and standard error were determined.
A1 = 0.000697 C1 + 0.06926 C2
A2 = 0.006191 C1 + 0.01746 C2

.(1)
.(2)

Analysis of Marketed Tablet Formulation:

Accurately weighed the 20 tablets and powdered. The
powder equivalent to 442mg of tablet was transferred
to 100ml volumetric flask which contains 37.5mg of
tramadol hydrochloride and 325mg of Paracetamol, to

1120

make 1:3 ratio of Paracetamol and tramadol 937.5mg

of pure tramadol is added to it. This mixture was
sonicated for 15 minutes and filtered through
Whatman filter paper No. 41. From which six dilutions
containing 2mcg/ml of Paracetamol and 6mcg/ml of
tramadol hydrochloride were made and the
absorbances taken at 243.5nm and 270.5nm. And by
using above equations concentrations of Paracetamol
(C1) and tramadol hydrochloride (C2) were determined.
Recovery studies:
Recovery studies were performed to judge the
accuracy of the method. 0.5ml of standard formulation
(100mcg/ml) was taken in three 10ml volumetric flask
and to it 80%, 100% and 120% (i.e. 0.4ml, 0.5ml,
0.6ml) of working standard solution (100mcg/ml)
added respectively and made the volume upto the
mark. The respective absorbances at 243.5nm and
270.5nm were recorded against the blank. The amount
of added concentration was determined from the
obtained absorbance values and percent recovery was
determined for each formulation. [12]
Robustness:
The evaluation of robustness was performed for
system suitability to ensure the validity of analytical
procedure. This was done by varying the instrument,
analyst, and time of study. The analysis was performed
on Shimadzu UV-Visible spectrophotometer, model1700 (Japan) and UV-Visible Spectrophotometer
model -1800 (Japan). Interday and intraday analysis
was performed by changing the analyst.

Results
The UV scan of standard solution between 200 400
nm showed the absorption maxima at 270.5nm for
tramadol hydrochloride and for paracetamol at
243.5nm. The Beers law was verified from the
calibration curve by plotting a graph of concentration
vs absorbance. The plots are shown in fig. 1 and 2.
Regression analysis showed very good correlation. The
calibration plot revealed zero intercept which is clear
by the regression analysis equation Y = mX + C.
(Where Y is absorbance, m is the slope and X is the
concentration in mcg/ml) as obtained by the least
square method. The results thus obtained are depicted
in Table No. I. The results of analysis for assay and
recovery study for tablet formulation was studied and
shown in Table No. II, III and IV. No significant
variations were observed on intraday and interday
analysis. Also no significant variations were observed
on changing the instrument.

Discussion
The spectrum of tramadol hydrochloride and
paracetamol in distilled water showed the absorption

Deepali Gharge et al /Int.J. PharmTech Res.2010,2(2)

maxima at 270.5 nm and at 243.5nm respectively. No

effect of dilution was observed on the maxima, which
confirmed the maxima at 270.5nm for tramadol
hydrochloride and at 243.5nm for paracetamol. The
statistical analysis of data obtained for the calibration
curves of tramadol hydrochloride and paracetamol in
pure solution indicated a high level of precision for the
proposed method, as evidenced by low value of
coefficient of variation. The coefficient of correlation
was highly significant. The linearity range was
observed between 0 20 mcg/ml for tramadol
hydrochloride and 3-15mcg/ml for paracetamol. The
plots clearly showed a straight line passing through
origin. The estimated method was validated by low
values of % RSD and standard error, indicating
accuracy and precision of the methods. Excellent

1121

recovery studies further proves the accuracy of the

method. Robustness of the method was studied by
varying the instrument, time of study and analyst.
Reproducibility of the results confirmed the robustness
of the method.

Conclusions
From the results and discussion the method described
in this paper for the determination of tramadol
hydrochloride and paracetamol from tablet formulation
is simple, accurate, sensitive reproducible and
economical. The proposed method utilizes inexpensive
solvents. The proposed method could be applied for
routine analysis in quality control laboratories.

Table No. I: Optical characteristics and precision

Optical characteristics
Paracetamol
Absorption maxima
243.5nm
Beer's law limit
2-20mcg/ml
Coefficient of Correlation
0.999721
Regression equation
Y=0.06926X+0.008329
Slope
0.06926
y intercept
0.008329
Molar absorptivity (lit/mole/cm)
9135.7055
Sandell's
sensitivity 0.016547
(mcg/Sq.cm/0.001)
Table No. II: Results of Analysis of tablet.
Formulation
270.5nm
% Estimated
270.5nm
243.5nm
243.5nm
270.5nm
Amount
found in mg
270.5nm
243.5nm
243.5nm

Tablet
P
T
P
T
P
T
P
T

Table No. III: Results of Analysis of tablet.

270.5nm
% COV
243.5nm
P
% Limit of detection
(%LOD)
T
% Limit of quantitation
P
(%LOQ)
T

0.05932
0.01204
0.1957
0.03974
0.5932
0.1204

COV - Coefficient of variation

Tramadol
270.5 nm
0 20 mcg/ml
0.999879
Y=0.006191X+0.002685
0.006191
0.002685
1796.041431
0.166945

107.84
102.62
100.70
103.83
323.375
37.34
322.368
37.14

Deepali Gharge et al /Int.J. PharmTech Res.2010,2(2)

Table No. IV Recovery study data

%
P
Conc. In
T
mcg/ml
P
270.5nm
Amount Found
T
270.5nm
in mcg/ml
P
243.5nm
T
243.5nm
P
270.5nm
% Recovery
T
270.5nm
P
243.5nm
T
243.5nm
243.5nm
S.D
270.5nm
% RSD

1122

80
9
27
8.674
26.1
8.538
25.5
96.37
96.66
94.86
94.44
0.0001
0.000265

100
10
30
10.254
30.75
10.264
30.79
102.54
102.5
102.64
102.63
0.0004
0.000122

120
11
33
10.957
32.88
11.008
33.02
99.60
99.63
100.08
100.06
0.000263
0.000449

243.5nm

0.01204

0.04007

0.02456

270.5nm

0.05932

0.0231

0.07956

S.D. Standard Deviation, RSD Relative Standard Deviation

Fig. 1: Calibration curve of Tramadol in distilled water
calibration curve for tramadol at 270.5nm

Y=0.006191X+0.002685

0.7
absorbances

0.6
0.5
0.4
0.3
0.2
0.1
0
0

20

40

60

80

100

120

conc

Fig. 2: Calibration curve of Paracetamol in distilled water

calibration curve for paracetamol at 243.5nm
1.2

Y=0.06926X+0.008329

1
abs

0.8
0.6
0.4
0.2
0
0

10
conc

15

20

Deepali Gharge et al /Int.J. PharmTech Res.2010,2(2)

Acknowledgements
Authors are grateful to Aristo Pharmaceuticals
Limited, Mumbai for providing the gift sample of
tramadol hydrochloride. We are also thankful to the
Principal and Head of Pharmaceutical Chemistry
Department of Government College of Pharmacy,
Karad for providing the necessary facilities to carry
out this work.

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