Stability indicating methods for the determination of aceclofenac

Article abstract of DOI:10.1016/S0014-827X(02)01271-5

Five new selective, precise and accurate methods for the determination of aceclofenac in the presence of its degradation product; diclofenac are described. Method A utilizes third derivative spectrophotometry at 242 nm. Method B is RSD₁ spectrophotometric method based on the simultaneous use of the first derivative of ratio spectra and measurement at 245 nm. Method C is a pH-induced difference (ΔA) spectrophotometry using UV measurement at 273 nm. Method D is a spectrodensitometric one, which depends on the quantitative densitometric evaluation of thin layer chromatogram of aceclofenac at 275 nm. Method E is RP-HPLC that depends on using methanol: water (60:40 v/v) as mobile phase at a flow rate of 1 ml/min and UV detection at 275 nm. Regression analysis of a beer's plot showed good correlation in the concentration ranges 5-40, 10-40, 15-50, 50-200, 1-50 μg/ml for methods A, B, C, D and E, respectively. These methods are suitable as stability indicating methods for the determination of aceclofenac in presence of its main degradation product, diclofenac. The proposed methods were applied for the analysis of the drug in its pharmaceutical formulation and the results obtained were compared with those obtained with the official B.P. method.

Full text of DOI:10.1016/S0014-827X(02)01271-5

Il Farmaco 58 (2003) 91ꢀ99
/
www.elsevier.com/locate/farmac
Stability indicating methods for the determination of aceclofenac
N.Y. Hasan *, M. Abdel-Elkawy, B.E. Elzeany, N.E. Wagieh
Department of Analytical chemistry, Faculty of Pharmacy, Cairo University, El-Kasr El-Aini Street, ET-11562 Cairo, Egypt
Received 30 August 2001; received in revised form 4 November 2001; accepted 27 April 2002
Abstract
Five new selective, precise and accurate methods for the determination of aceclofenac in the presence of its degradation product;
diclofenac are described. Method A utilizes third derivative spectrophotometry at 242 nm. Method B is RSD1 spectrophotometric
method based on the simultaneous use of the first derivative of ratio spectra and measurement at 245 nm. Method C is a pH-induced
difference (DA) spectrophotometry using UV measurement at 273 nm. Method D is a spectrodensitometric one, which depends on
the quantitative densitometric evaluation of thin layer chromatogram of aceclofenac at 275 nm. Method E is RP-HPLC that
depends on using methanol: water (60:40 v/v) as mobile phase at a flow rate of 1 ml/min and UV detection at 275 nm. Regression
analysis of a beer’s plot showed good correlation in the concentration ranges 5ꢀ
/
40, 10ꢀ
/
40, 15ꢀ
/
50, 50ꢀ
/
200, 1ꢀ50 mg/ml for methods
/
A, B, C, D and E, respectively. These methods are suitable as stability indicating methods for the determination of aceclofenac in
presence of its main degradation product, diclofenac. The proposed methods were applied for the analysis of the drug in its
pharmaceutical formulation and the results obtained were compared with those obtained with the official B.P. method.
´
# 2003 Editions scientifiques et me´dicales Elsevier SAS. All rights reserved.
Keywords: Aceclofenac; Derivative spectrophotometry; RSD1 spectrophotometry; DA spectrophotometry; TLC-densitometry; RP-HPLC
1. Introduction
fluorometric [4] and chromatographic [5] methods.
None of these reported methods were used for the
determination of aceclofenac in presence of its degrada-
tion product.
Aceclofenac is 2-[(2,6-Dichlorophenyl) amino] ben-
zene acetic acid carboxymethyl ester and is used as anti-
inflammatory drug [1]. The structural formulae of
aceclofenac(I) and its main degradation product, diclo-
fenac(II), are as follows:
The main task of this work is to establish simple and
accurate third derivative (D3), ratio-spectra first deriva-
tive (RSD1) and difference (DA) spectrophotometric,
densitometric and high-performance liquid chromato-
graphic (HPLC) methods which could be used as
stability indicating methods for the determination of
aceclofenac in presence of its main degradation product,
diclofenac. These methods can be used also for the
routine and quality control analysis of aceclofenac in
raw material and pharmaceutical formulations.
The European pharmacopoeia supplement 2000 and
the British pharmacopoeia reported HPLC methods for
the determination of aceclofenac in presence of diclofe-
nac [1,2]. Other methods include titrimetric [1], electro-
chemical [2,3], spectrophotometric [4], spectro-
2. Experimental
2.1. Apparatus
1. Shimadzu UVꢀ
photometer with 1 cm quartz cuvets (Dlꢁ
2. UV lamp with short wavelength 254 nm.
/
VIS1601 PC double beam spectro-
/8).
* Corresponding author.
E-mail address: newsaa74@hotmail.com (N.Y. Hasan).
´
0014-827X/03/$ - see front matter # 2003 Editions scientifiques et me´dicales Elsevier SAS. All rights reserved.
PII: S 0 0 1 4 - 8 2 7 X ( 0 2 ) 0 1 2 7 1 - 5

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N.Y. Hasan et al. / Il Farmaco 58 (2003) 91ꢀ99
/
3. TLC plates (20ꢂ
/
20 cm) precoated with silica gel 60
volumetric flask and complete to volume with
absolute ethanol.
F254 (E.MERCK).
4. Shimadzu-dual wavelength flying spot CS-9301
densitometer.
5. Shimadzu Class-LC 10 liquid chromatographic
(iii) HPLC method (100 mg/ml): Transfer 10 ml of
aceclofenac stock standard solution to a 100 volu-
metric flask and complete to volume with metha-
nol:water (60:40 v/v).
system equipped with Shimadzu SPD-10 A diode
array UV-detector, ZORBAX† C18 (15 cmꢂ
4.6
/
mm i.d., 5 mm particle size) column was used as
stationary phase.
2.3.3. Degradate stock solution (1 mg/ml)
Weigh accurately 100 mg of the degradate, transfer to
a 100 ml volumetric flask, add 40 ml absolute ethanol,
shake for 10 min and complete to volume with absolute
ethanol.
2.2. Samples
2.2.1. Pure samples
Aceclofenac pure sample was kindly supplied by
Bristol-Myers squibb Egypt. The purity of the sample
was found to be 99.9% according to the B.P. method
(1998) [1].
2.3.4. Degradate working standard solutions
(i) D3, RSD1 and DA spectrophotometric methods
(100 mg/ml): Transfer 10 ml of degradate stock
solution to a 100 volumetric flask and complete to
volume with absolute ethanol.
(ii) Densitometric method (0.5 mg/ml): Transfer 50 ml
of degradate stock solution to a 100 ml volumetric
flask and complete to volume with absolute ethanol.
(iii) HPLC method (100 mg/ml): Transfer 10 ml of
degradate stock solution to a 100 volumetric flask
and complete to volume with methanol:water (60:40
v/v).
2.2.2. Market samples
Bristaflam† tablets (Bristol-Myers Squibb, Egypt)
each tablet was claimed to contain 100 mg of aceclofe-
nac. Batch Number C005537 and H82063.
2.2.3. Preparation of the degradation product
0.3 g of pure aceclofenac were heated at reflux with 20
ml 1 N sodium hydroxide for 3 h. The solution was
allowed to cool then 10 ml of 2.0 N sulphuric acid were
added and the solution was heated to 90 8C. The
obtained precipitate was filtered, washed and recrysta-
lized from ether. The obtained powder (melting point
2.4. Laboratory prepared mixtures
(m.p.)ꢁ157 8C) was identified and ensured using IR-
/
2.4.1. Third derivative (D3) spectrophotometric method
Transfer accurately aliquots from aceclofenac work-
spectrophotometry and TLC technique, then it was used
for the preparation of the stock solution of the
degradate.
ing standard solution equivalent to (50ꢀ
series of 10 ml volumetric flasks, add portions equiva-
lent to 10ꢀ50% of the degradate from its working
/
400 mg) into a
/
2.3. Reagents and solutions
standard solution to the same flasks, complete to the
mark with absolute ethanol.
All chemicals and reagents are of pure analytical
grade; in particular: absolute ethanol and methanol
HPLC grade were from B.D.H. and tetrahydrofuran
AR was from E. Merck.
2.4.2. RSD1 spectrophotometric method
Transfer accurately aliquots from aceclofenac work-
ing standard solution equivalent to (100ꢀ
series of 10 ml volumetric flasks, add portions equiva-
lent to 10ꢀ50% of the degradate from its working
standard solution to the same flasks, complete to the
mark with absolute ethanol.
/
400 mg) into a
2.3.1. Aceclofenac stock standard solution (1 mg/ml)
Weigh accurately 100 mg of aceclofenac powder,
transfer to a 100 ml volumetric flask, add 40 ml absolute
ethanol, shake for 10 min and complete to volume with
absolute ethanol.
/
2.4.3. Difference (DA) spectrophotometric method
Transfer accurately aliquots from aceclofenac work-
2.3.2. Aceclofenac working standard solutions
(i) D3, RSD1 and DA spectrophotometric methods
(100 mg/ml): Transfer 10 ml of aceclofenac stock
standard solution to a 100 volumetric flask and
complete to volume with absolute ethanol.
(ii) Densitometric method (0.5 mg/ml): Transfer 50 ml
of aceclofenac stock standard solution to a 100 ml
ing standard solution equivalent to (150ꢀ
two sets of 10 ml volumetric flasks, add portions
equivalent to 10ꢀ40% of the degradate from its working
standard solution to the same flasks, complete to the
mark in one set with 0.1 N sodium hydroxide and in the
other set with 0.1 N hydrochloric acid.
/
500 mg/ml) into
/

N.Y. Hasan et al. / Il Farmaco 58 (2003) 91ꢀ
/
99
93
2.4.4. Densitometric method
Transfer accurately aliquots from aceclofenac work-
was calculated from the regression equation. Results
obtained are given in Table 1.
ing standard solution equivalent to (0.5ꢀ
series of 10 ml volumetric flasks, add portions equiva-
lent to 10ꢀ95% of the degradate from its working
/
2 mg) into a
2.5.2. Method B, RSD1 spectrophotometric method
/
standard solution to the same flasks, complete to the
mark with absolute ethanol.
2.5.2.1. Linearity. Accurate aliquots equivalent to (100ꢀ
/
400 mg) of aceclofenac were transferred from its working
standard solution into a series of 10 ml volumetric flasks
then made up to volume using absolute ethanol.The
absorption spectra of the these solutions were divided by
the ‘the divisor’ (the absorption spectrum of 5 mg/ml of
the degradate) and the ratio spectra thus obtained were
smoothed and the first derivatives of the ratio spectra
were recorded. The peak amplitude at 245 nm was
measured. The calibration curve representing the rela-
tionship between the measured amplitude and the
corresponding concentration was constructed.
2.4.5. HPLC method
Transfer accurately aliquots from aceclofenac work-
ing standard solution equivalent to (10ꢀ
series of 10 ml volumetric flasks, add portions equiva-
lent to 10ꢀ99% of the degradate from its working
/
500 mg) into a
/
standard solution (100 mg/ml) to the same flasks,
complete to the mark with methanol: water (60:40 v/v).
2.5. Procedures
2.5.1. Method A, third derivative spectrophotometric
method
2.5.2.2. Assay of prepared mixtures. The ratio spectra
first derivative curves of the laboratory-prepared mix-
tures containing different ratios of aceclofenac and its
degradate were measured. The peak amplitude at 245
nm was measured, then the concentration of AC in the
prepared mixtures was calculated from the regression
equation. Results obtained are given in Table 1.
2.5.1.1. Linearity. Accurate aliquots equivalent to (50ꢀ
/
400 mg) of aceclofenac were transferred from its working
standard solution into a series of 10 ml volumetric flasks
then made up to volume using absolute ethanol. The
third derivative UV spectra of the UV-spectrum of each
solution against absolute ethanol as a blank were
recorded. The peak height using 242 nm as maxima
and zero- crossing line as minima was measured. The
calibration curve representing the relationship between
the measured peak height and the corresponding con-
centration was constructed.
2.5.3. Method C, difference (DA) spectrophotometric
method
2.5.3.1. Linearity. Accurate aliquots equivalent to (150ꢀ
/
500 mg) of aceclofenac were transferred from its working
standard solution (100 mg/ml) into two sets of 10 ml
volumetric flasks. The volume was diluted in one set
with 0.1 N sodium hydroxide and in the other set with
0.1 N hydrochloric acid. The DA spectrum for each
concentration was recorded by placing the alkaline
solution in the reference beam and the acid solution in
2.5.1.2. Assay of prepared mixtures. The D3 spectra of
the laboratory-prepared mixtures containing different
ratios of aceclofenac and its degradate were recorded.
The peak heights at 242 nm were measured. The
concentration of aceclofenac in the prepared mixtures
Table 1
Comparison between the proposed methods and the reported one for the determination of aceclofenac in the presence of its degradate
b
Sample
number
Percentage of
degradate
Found (%)
D3 method
a
RSD1 method
DA method
Densitometric
method
RP-HPLC
method
B.P. (1998)
method
1
2
3
4
5
6
7
8
10
20
30
40
50
60
95
98
100.60
99.80
99.86
100.90
99.66
99.60
99.10
98.40
98.90
98.40
100.30
99.00
98.80
100.01
100.24
99.79
99.95
99.80
99.79
100.30
98.99
98.96
98.82
99.02
99.90
98.94
99.03
99.20
100.20
106.96
113.20
116.56
125.12
150.35
176.58
188.56
100.41
Mean9
/
SD
100.1649
/
0.55
98.889
/
0.51
99.629
/
0.84
99.989
/
0.21
99.1190.33
/
a
Average of four experiments.
b
Found (%)*Recovery percentage of aceclofenac.
/

94
N.Y. Hasan et al. / Il Farmaco 58 (2003) 91ꢀ99
/
the sample beam. The calibration curve relating the DA
at 273 nm to AC concentration was constructed.
2.5.5.2. Assay of prepared mixtures. The specified HPLC
method was followed for the analysis of laboratory
prepared mixtures containing different ratios of aceclo-
fenac and its degradate. The peak area values for
aceclofenac were measured then the concentration of
aceclofenac in the prepared mixtures was calculated
from the regression equation.
2.5.3.2. Assay of prepared mixtures. The DA spectra of
the laboratory-prepared mixtures containing different
ratios of AC and its degradate were recorded. The peak
amplitude at 273 nm was measured, and then the
concentration of aceclofenac in the prepared mixtures
was calculated from the regression equation. Results
obtained are given in Table 1.
2.5.6. Assay of pharmaceutical formulation
The contents of ten tablets of Bristaflam† were
thoroughly powdered and mixed, an amount of the
powder equivalent to 100 mg of AC was accurately
weighed in 250 ml beaker, 70 ml of absolute ethanol was
added, stirred magnetically for about 30 min then
filtered through a filter paper into a 100 ml volumetric
flask, the beaker and the funnel were washed and the
volume was completed with absolute ethanol. The
solutions were diluted to the same concentrations of
working standard solutions and treated according to
linearity for each method.
2.5.4. Method D, spectrodensitometric method
2.5.4.1. Linearity. Accurate aliquots equivalent to (0.5ꢀ
/
2 mg) of aceclofenac were transferred from its working
standard solution (0.5 mg/ml) to a series of 10 ml
volumetric flasks then the volume was completed with
ethanol. 10 ml of each solution was applied to a thin
layer chromatographic plate (20ꢂ20 cm) using 10 ml
/
micro syringe. Spots were spaced 2 cm apart from each
other, 1.5 cm from the bottom edge of the plate, the
plate was placed in chromatographic tank previously
saturated for 1 h with the developing mobile phase
Tetrahydrofuran: methanol (90:10 v/v). The plate was
developed by ascending chromatography through a
distance of 16 cm, dried at room temperature (r.t.); the
spots were detected under UV lamp, and scanned at 275
nm. (Photomode: reflection and scan mode: zigzag). The
calibration curve representing the relationship between
the recorded area under the peak and the corresponding
concentration was constructed.
3. Results and discussion
Aceclofenac is liable to alkaline hydrolysis. The main
degradation product of AC; ‘diclofenac’ [1]; was pre-
pared in the laboratory by complete alkaline hydrolysis
of aceclofenac. This was achieved by reflux with 1 N
sodium hydroxide for 3 h. Heating with sulphuric acid
at 90 8C leads to decomposition of glycolic acid into
formaldehyde, carbon monoxide and water [9].
3.1. Method A, third derivative UV-spectrophotometric
method
2.5.4.2. Assay of prepared mixtures. About 10 ml of
different samples of the laboratory prepared mixtures
were applied to a thin layer chromatographic plate;
proceed as mentioned under linearity starting from
‘Spots were spaced. . .’. The area under the peak was
recorded and the concentration of AC was calculated
from the regression equation. Results obtained are given
in Table 1.
Zero order absorption spectra of aceclofenac and its
degradate in absolute ethanol show severe overlapping
which interferes with the direct determination of pure
aceclofenac (Fig. 1).
Derivative UV spectrophotometry has been first
suggested during the last decade and soon became a
well-established technique for the analysis of drugs in
mixtures and in formulations [6]. The principle advan-
tage of derivative spectrophotometry is the improve-
ment of resolution of overlapping absorption bands, the
accuracy and precision of UV absorption methods are
considerably improved, and therefore derivative spec-
troscopy has been used in quantitative analysis when the
analyte to be determined is present in admixture with
other components [7].
The first (D1) and second (D2) derivative spectro-
photometric techniques were not able to overcome this
overlapping.
As shown in Fig. 2, it is clear that the overlapping
observed in the zero order absorption spectra was
eliminated and sharply defined, well separated peak at
2.5.5. Method E, RP-HPLC method
2.5.5.1. Linearity. Accurate aliquots equivalent to (10ꢀ
/
500 mg/ml) of aceclofenac working standard solution
(100 mg/ml) were transferred into a series of 10 ml
volumetric flasks. Methanol: water (60:40 v/v) was
added to volume to give a final concentration range
from 1 to 50 mg/ml. Twenty ml of the solution from each
of the above was injected and the chromatograms were
recorded maintaining the flow rate at 1 ml/min and
monitoring the effluent at 230 nm. Peak area values were
then plotted as a function of aceclofenac concentration
to obtain the calibration curve.

N.Y. Hasan et al. / Il Farmaco 58 (2003) 91ꢀ
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99
95
pure aceclofenac and the following regression equation
was obtained:
H ꢁ0:047Cꢃ0:0137; rꢁ0:9997
where H is the peak height in millimeter at 242 nm, C is
the concentration in mg/ml and r is the correlation
coefficient.
3.2. Method B, RSD1 spectrophotometric method
This method is based on the measurement of the UV
absorption spectra of sample solution and storing them
in the computer; then, the stored data were divided by a
standard spectrum of the interfering component. The
ratio spectra thus obtained were smoothed and the first
derivatives were recorded [8].
Fig. 3 shows the ratio spectrum of aceclofenac and its
degradate (spectrum of AC divided by the spectrum of 5
mg/ml of the degradate) and its first derivative. As can be
seen, the peak at 245 nm for intact aceclofenac which
lies at the zero crossing point of its degradate can be
adopted for the determination of aceclofenac in presence
of its degradate and in pharmaceutical formulation.
The calibration curve was obtained by plotting the
peak amplitude at 245 nm of the first derivatives of the
ratio spectra of aceclofenac and it shows linear relation-
Fig. 1. Zero-order spectra of the ethanolic solutions of intact
aceclofenac (30 mg/ml), [_ _ _] and degradation product (5 mg/ml), [---].
ship in the range of 10ꢀ40 mg/ml and the following
/
regression equation was calculated:
Aꢁ0:035Cꢄ0:075; rꢁ0:9998
where A stands for the peak amplitude at 245 nm, C for
the concentration in mg/ml and r is the correlation
coefficient.
3.3. Method C, DA spectrophotometric method
The DA spectra between 0.1 N sodium hydroxide and
0.1 N hydrochloric acid for intact aceclofenac and its
degradate were recorded and from these spectral char-
acteristics it is clear that the DA peak at 273 nm for the
intact aceclofenac between 0.1 N hydrochloric acid and
0.1 N sodium hydroxide could be considered as the lmax
most suitable for adopting the DA technique for the
selective determination of intact aceclofenac in presence
of its degradate as at this maxima, DA for the latter
reads zero (Fig. 4).
Fig. 2. Third derivative spectra of the ethanolic solutions of intact
aceclofenac (30 mg/ml), [_ _ _] and degradation product (5 mg/ml), [---].
A calibration curve was constructed relating the DA
values at 273 nm to drug concentrations showing perfect
242 nm for the intact molecule which lies at the zero
crossing of its degradate was obtained and used for the
D3 spectrophotometric determination of intact aceclo-
fenac in presence of its degradate.
linearity in the range of 15ꢀ50 mg/ml from which the
/
following regression equation was calculated:
Aꢁ0:0098Cꢃ0:144; rꢁ0:9995
By applying the D3 spectrophotometric method, a
linear correlation was obtained between the peak height
where A stands for the peak amplitude at 273 nm, C for
the drug concentration in mg/ml and r is the correlation
coefficient.
and the concentration over the range 5ꢀ40 mg/ml for
/

96
N.Y. Hasan et al. / Il Farmaco 58 (2003) 91ꢀ99
/
3.4. Method D, densitometric method
where A is the area under the peak, C is the correspond-
ing concentration in mg/ml and r is the correlation
coefficient.
This method was applied for the determination of
aceclofenac. Complete separation of aceclofenac was
obtained using Tetrahydrofuran: methanol (90:10 v/v)
as developing mobile phase. Quantitatively the chroma-
togram was scanned densitometrically at 275 nm. By
applying this technique a linear correlation was ob-
tained between the area under the peak and the concen-
tration of aceclofenac in the range of 50ꢀ200 mg/ml. The
following regression equation was calculated for
aceclofenac:
3.5. Method E, RP-HPLC method
A simple and stability indicating isocratic HPLC
method was adopted for the analysis of aceclofenac in
presence of its degradate and in pharmaceutical for-
mulation. The initial study involved the use of different
percentages of methanol in the mobile phase. The best
peak shape was obtained with methanol: water 60:40 v/v
with retention time of 1.9 min. The final dilution of
/
Aꢁ0:005Cꢃ0:063; rꢁ0:9996
Fig. 3. Ratio-spectra and first derivative curves of the ethanolic solutions of intact aceclofenac (20 mg/ml) using 5 mg/ml of degradation product as the
divisor, [_ _ _].

N.Y. Hasan et al. / Il Farmaco 58 (2003) 91ꢀ
/
99
97
Fig. 5. HPLC Chromatogram of (a) pure aceclofenac, 20 mg/ml; (b)
degradation product ‘‘diclofenac’’, 10 mg/ml.
Fig. 4. Difference spectra of intact aceclofenac (15 mg/ml), [_ _ _] and
degradation product (5 mg/ml), [---].
samples has been done using methanol: water (60:40
v/v).
A typical chromatogram of pure aceclofenac is shown
in Fig. 5. The chromatograms as shown in Fig. 5 showed
no peak interferences between the drug and its degra-
date.
the accuracy of the proposed methods are not affected
by the presence of up to 50, 50, 40, 95, and 99% of the
degradation product in the third, RSD1 and DA
spectrophotometric, TLC- densitometric and RP-
HPLC methods respectively.
The proposed methods were applied successfully for
the analysis of aceclofenac in its dosage form. Results
obtained are given in Table 2.
The calibration curve for aceclofenac was constructed
by plotting peak area versus concentration and it
showed good linearity in the range of 1ꢀ50 mg/ml. The
/
The validity of the proposed methods was further
assessed by applying the standard addition technique.
Results obtained are given in Table 3.
regression equation was calculated and found to be:
Aꢁ0:009Cꢃ0:025; rꢁ0:9996
The results obtained by applying the proposed
methods were statistically compared with those obtained
by applying the reference method. Table 4 shows that
the values of calculated t and F are less than the
tabulated ones indicating that there is no significant
difference between the methods. Thus, the pro-
posed methods could be applied as stability indicating
methods for the routine and quality control analysis of
aceclofenac in raw material and pharmaceutical formu-
lations.
where A is the peak area, C is the corresponding
concentration and r is the correlation coefficient.
To assess the stability indicating selectivity of the
proposed methods for the analysis of aceclofenac with-
out interference from its main degradation product,
diclofenac, separate aliquots of the degradation product
of aceclofenac were mixed with the intact drug in
different ratios and analyzed by the proposed methods.
The results obtained are shown in Table 1. It is clear that
Table 2
Comparison between the proposed methods and the reported one for the determination of aceclofenac in pure form and in its pharmaceutical
formulation
Preparation
Found (%)9
/
SD
D3 method
RSD1 method
DA method
Densitometric
method
RP-HPLC
method
B.P. method
Pure sample
Bristaflam tablets B.N. C005537
Bristaflam tablets B.N. H82063
100.1649
100.429
99.659
/
0.55
98.889
100.019
99.919
/
0.51
99.629
100.429
100.129
/
0.84
99.989
99.689
99.529
/
0.21
99.119
98.909
99.309
/
0.33
99.369
98.819
99.949
/
0.32
0.35
0.62
/0.821
/
0.121
0.143
/0.252
/
0.392
0.313
/0.183
/
/0.522
/
/0.521
/
/0.742
/

98
N.Y. Hasan et al. / Il Farmaco 58 (2003) 91ꢀ99
/
Table 3
Application of standard addition technique to the analysis of pharmaceutical preparation of aceclofenac by the proposed methods
Method
Preparation
Claimed taken
(mg/ml)
Pure added
(mg/ml)
Pure found
(mg/ml)
Recovery of added
(mg/ml)
D3 method
Bristaflam tablets B.N. C005537
20.00
20.00
20.00
1.00
5.00
10.00
15.00
20.00
5.05
10.07
14.94
20.41
101.00
100.70
99.60
102.05
Mean9
/
SD
100.849
/
1.007
0.333
0.085
0.154
0.588
RSD1 method
Bristaflam tablets B.N. C005537
Bristaflam tablets B.N. C005537
Bristaflam tablets B.N. C005537
Bristaflam tablets B.N. C005537
5.00
10.00
15.00
20.00
4.99
10.02
14.99
19.88
99.80
100.20
99.93
99.40
Mean9
/
SD
99.839
99.80
99.80
99.93
99.96
/
DA method
5.00
10.00
15.00
25.00
4.99
9.98
14.99
24.99
Mean9
/
SD
99.879
/
Densitometric method
0.70
0.80
0.95
1.00
0.6974
0.7991
0.9495
0.9969
99.63
99.89
99.95
99.69
Mean9
/
SD
99.799
99.80
99.20
99.40
98.40
/
RP-HPLC method
20.00
10.00
15.00
25.00
30.00
9.98
14.88
24.85
29.52
Mean9
/
SD
99.209
/
Table 4
Statistical analysis of the results obtained by the five proposed and B.P. (1998) methods for the determination of aceclofenac
B.P. (1998)
method
D3
spectrophotometric spectrophotometric
method method
RSD1
DA
spectrophotometric
method
Densitometric
method
HPLC method
Concentration 300 mg
range
5ꢀ/40 (ug/ml)
10ꢀ/40 (ug/ml)
15ꢀ/50 (ug/ml)
50ꢀ
/
200 (ug/ml) 5ꢀ50 (ug/ml)
/
Mean (%)
SD
99.44
0.86
8
100.12
0.60
100.047
0.13
99.36
0.39
98.76
0.48
99.13
0.67
N
8
0.376
7
0.0164
8
0.154
8
0.259
8
0.451
Variance
Student’s t-test
F test
0.740
0.215 (1.761)
1.09 (3.575)
0.698 (1.771)
1.01 (4.445)
0.604 (1.761)
1.03 (3.575)
0.563 (1.761)
1.21 (3.575)
0.747 (1.761)
1.08 (3.575)
*, values in parenthesis are the theoretical values of t and F (at Pꢁ0.05).
/
4. Conclusion
powder or in pharmaceutical formulations [10]. Statistical
analysis of the results obtained by the five proposed
methods and by the reference method of B.P. (1998),
revealed no significant difference within a probability of
95%. method.
The suggested methods are simple, accurate, selective
and sensitive with no significant difference of the
precision. Application of the proposed methods to the
analysis of aceclofenac in laboratory prepared mixtures
and pharmaceutical formulation shows that neither the
degradation products nor the excipients interfere with the
determination, indicating that the proposed methods
could be applied as stability indicating methods for the
determination of pure aceclofenac and in presence of its
main degradation product, diclofenac, either in bulk
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