Q–Analysis Spectrophotometric method for the simultaneous determination of Nabumetone and Paracetamol in API and in tablet dosage form

C.K.Oza¹*, R. Nijhawan¹, M. K. Pandya², A. J. Vyas³, A. I. Patel³

^1.Xylopia, Ahmadabad, India.

^2.R.K University, Rajkot, India.

^3.B. K. Mody Govt. Pharmacy College, Rajkot, India.

*Corresponding Author E-mail: chiragkoza@g mail.com

ABSTRACT:

A simple, sensitive and rapid Q –Analysis spectrophotometric method has been developed for simultaneous estimation of Nabumetone and Paracetamol from tablets. Here, absorbance is measured at two wavelengths. One being the λmax of Paracetamol (248.4 nm) and other being a wavelength of equal absorptivity of two components (238.6 nm) i.e. an isoabsorptive point. Linearity of response was observed in concentration range of 2 – 30 µg/ml for Nabumetone and 2 – 20 µg/ml for Paracetamol. The results of method were validated statically and by recovery studies. The % recovery was found to be 98.09% to 100.23% for Nabumetone whereas 99.88% to 101.81% for Paracetamol. The results of analysis in terms of % label claim was 98.72% ± 0.42 for Nabumetone and 101.62% ± 0.26 for Paracetamol for a formulation analyzed. The developed method was found to be accurate, precise, selective and rapid for simultaneous estimation of Nabumetone and Paracetamol in tablets.

KEYWORDS: Q – Analysis spectrophotometric method, Nabumetone, Paracetamol, Methanol, isoabsorptive point.

INTRODUCTION:

Nabumetone, 4-(6-methoxynaphthalen-2-yl) butan-2-one, is a nonsteroidal anti- inflammatory drug (NSAID) of naphtylalkanone class. The drug has proved to be effective in the treatment of rheumatoid arthritis, osteoarthritis and acute soft tissue injuries. Nabumetone is a prodrug which undergoes extensive first pass metabolism to 6- methoxy-2-naphthylacetic acid (6-MNA), the major circulating metabolite; 6- MNA is largely responsible for the therapeutic efficacy of nabumetone[1-3] (fig. 1). Paracetamol (PARA) is chemically N-(4-hydroxyphenyl) acetamide (fig 1), It has analgesic and antipyretic activity [1, 4]. Combination of Nabumetone and Paracetamol is effective as these agents act through different analgesic mechanisms and act synergistically. The combination offers faster as well as prolonged relief from pain and inflammation [3].

A: Paracetamol B: Nabumetone

Figure 1: Structure of Nabumetone and Paracetamol [2, 4]

Many RP-HPLC methods [5-7] have been reported for the determination of Nabumetone and its metabolite in tablet dosage form and also in human plasma. Simultaneous estimation of Naproxen and Nabumetone was also reported by RP-HPLC in human plasma, human urine and in pharmaceutical. While spectrophometry,[9-14] HPLC,[15-25] LC-MS[26] and capillary electrophoresis [27] had been reported for determination of PCM. But no method is available for simultaneous estimation of Nabumetone and Paracetamol in tablet dosage form.

Therefore, it was the purpose of this research to develop a rapid, simple, sensitive, reliable, and validated analytical method for the measurement of both drugs, which will be the first for their simultaneous analysis in API and tablet dosage form. The present Q analysis spectrophotometric method was validated following the ICH guidelines [28].

Figure 2: Overlain Spectra of 10 µg/ml of NABU and 10 µg/ml of PCM in methanol

Figure 3: Overlain Spectra of NABU at different wavelength

EXPERIMENTAL:

Chemicals and Reagents Used

The reference standard of Nabumetone and Paracetamol were obtained as gift samples from Ipca laboratory and Biodeal laboratory respectively. Methanol (AR Grade, S. D. Fine Chemicals Ltd., Mumbai, India) and Whatman filter paper no. 41 (Millipore, USA) were used in the study. Tablet dosage form used for estimation in dosage form was NILTIS-P manufactured by Ipca Laboratory. Each tablet containing 500 mg of Nabumetone and 500 mg of Paracetamol.

Instrumentation

Double beam UV-visible spectrophotometer (Shimadzu, model 1601) attached to computer software UV-Probe 2.21 having two matched quartz cells with 1 cm light path. Analytical balance (Keroy Pvt. Ltd.), pH meter (Analab scientific instrument Ltd.).

Preparation of Standard Stock Solutions of Nabumetone and Paracetamol

Standard solution of NABU and PCM were prepared in methanol by dissolving 10 mg of each in separate 100 ml volumetric flask to get stock solution having concentration 100 µg/ml of NABU and 100 µg/ml of PCM. From these stock solutions, working standard solutions of both drugs containing 10 µg/ml was prepared by appropriate dilutions.

Determination of iso-absorptive point and wavelength of maximum absorbance

Working standard solutions as prepared above were scanned in the range of 200-400 nm against methanol as blank to determine wavelength of maximum absorption. Wavelengths of maximum absorption were found to be 229.2 nm, 261.0 nm, 270.4 nm, 317.8 nm and 332.6 nm for NABU and 248.4 nm for PCM. Iso-absorptive point was found at 238.6 nm as depicted in Figure 2.

5.2.3.4 Selection of Analytical wavelength for NABU and PCM

In the Q – Analysis method, the working standard solution of NABU and PCM were scanned in the entire range from 200 to 400 nm. Two wavelengths were selected. One being the lmax of one of the component (l₂) and the other being a wavelength of equal absorptivity of the two components (l₁) i.e. an isoabsorptive point. Hence these two wavelengths 238.6 nm (isoabsorptive point) and 248.4 nm (lmax of PCM) were selected for the determination of Nabumetone and Paracetamol, as depicted in Figure 2. Overlain Spectra of NABU and PCM at different wavelength are shown in Figure 3 and Figure 4.

Preparation of Binary mixtures

Suitable aliquots of standard stock solutions of NABU and PCM were mixed and diluted with methanol to obtain different binary mixture solutions containing NABU and PCM in 1:1 ratio (in equal concentrations). Concentrations of solution (binary mixture) in the range of 2-20 µg/ml were prepared for the calibration curve of the drugs

Figure 4: Overlain Spectra of PCM at different wavelength

Figure 5: Calibration Curve of NABU at 238.6 nm

Figure 6: Calibration Curve of NABU at 248.4 nm

Preparation of Calibration Curve

For each drug, appropriate aliquots were pipettes out from standard stock solution into a series of ten 10 ml volumetric flasks. Volume was made up to the mark with methanol to get solutions of final concentrations in the range of 2- 30 µg/ml for NABU and 2-20 µg/ml PCM. The absorbance of each solution was measured at both the wavelength 238.6 nm and 248.4 nm. Calibration curves were constructed for NABU Figure 5 and PCM Figure 6 by plotting absorbance versus concentrations at both wavelengths. Each reading was average of five determinations.

Equation for estimation of Nabumetone and Paracetamol from pharmaceutical dosage form

The absorptivity coefficients of these two drugs were determined using calibration curve equation. The concentration of NABU and PCM were determined using the following simultaneous equations.

Where, A1and A2 are the absorbance of the mixture at 238.6 nm and 248.4 nm respectively; aX₁ and aY₁ are absorptivity of NABU and PCM respectively at 238.6 nm; aX₂ and aY₂ are absorptivity of NABU and PCM respectively at 248.4 nm; Q_M=A₂/A₁, Q_X= aX₂/ aX₁ and Q_Y= aY₂/ aY₁.

Analysis of Marketed formulation

Twenty tablets were weighed and crushed separately to fine powder. A quantity of powder equivalent to 10 mg of Nabumetone and 10 mg Paracetamol was weighed and transferred to 100 ml volumetric flask and mixed with methanol (70ml) and sonicated for 20 min. Allow solution to cool and then make up the volume with methanol. The solution was filtered through whatmann filter paper No. 41. The above solution (1ml) was transferred in 10 ml volumetric flask and diluted to mark with methanol to obtain final solution with Nabumetone (10 µg/ml) and Paracetamol (10 µg/ml). For this method, absorbance of the sample solution, i.e. A₁ and A₂ were recorded at 238.6 nm and 248.4 nm.

Table 1: Calibration Data for Nabumetone

Concentration of NABU (µg/ml)	Absorbance at wavelength		Absorptivity at wavelength
	238.6 nm	248.4 nm	238.6 nm	248.4 nm
2	0.163	0.033	815.00	163.00
4	0.325	0.067	812.50	167.50
6	0.492	0.098	820.00	163.33
8	0.655	0.134	818.75	167.50
10	0.805	0.168	805.00	168.00
12	0.979	0.201	815.83	167.50
16	1.323	0.268	826.87	167.50
18	1.475	0.303	819.44	168.33
20	1.604	0.339	802.00	169.50
24	1.952	0.405	813.33	168.75
30	2.465	0.514	821.66	171.33

Table 2: Calibration Data for Paracetamol

Concentration of PCM (µg/mL)	Absorbance at wavelength		Absorptivity at wavelength
	238.6 nm	248.4 nm	238.6 nm	248.4 nm
2	0.163	0.204	815.00	1020.00
4	0.328	0.405	820.00	1012.50
6	0.488	0.607	813.33	1011.66
8	0.648	0.811	810.00	1013.75
10	0.808	0.998	814.23	998.00
12	0.972	1.203	811.00	1002.50
14	1.129	1.405	816.42	1003.57
16	1.298	1.609	808.25	1005.62
20	1.634	1.977	817.00	988.50

RESULTS AND DISCUSSION:

Method Validation

Linearity

Data for calibration curve and regression analysis are given in Table 1 and Table 2 which shown that method shows good linearity in concentration range of 2-30 µg/ml for NABU and 2-20 µg/ml for PCM. (Figure 5, 6, 7 and 8).

The following equations for straight line were obtained for NABU and PCM. Absorptivity value of NABU and PCM are shown in Table 3.

Linear equation for NABU at 238.6 nm:

y = 0.0813 x + 0.0018, r² = 0.9997

Linear equation for NABU at 248.4 nm:

y = 0.017 x - 0.0028, r² = 0.9998

Linear equation for PCM at 238.6 nm:

y = 0.0812x - 0.0028, r2 = 0.9998

Linear equation for PCM at 248.4 nm:

y =0.0993x + 0.0105, r2 = 0.9998

Table 3: Absorptivity value of NABU and PCM

Absorptivity at Wavelength Drugs	238.6 nm	248.4 nm
Nabumetone	814.47	167.75
Paracetamol	812.99	1005.94

Figure 7: Calibration Curve of PCM at 238.6 nm

Figure 8: Calibration Curve of PCM at 248.4 nm

Precision

The precision of an analytical method is the degree of agreement among individual test results when the method is applied repeatedly to multiple samplings of homogenous samples. It provides an indication of random error results and was expressed as coefficient of variation.

a) Repeatability

Standard solutions of NABU (2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28 and 30 µg/ml) and PCM (2, 4, 6, 8, 10, 12, 14, 16, 18 and 20 µg/ml) were prepared and absorbance was measured at 238.6 nm and 248.4 nm taking the methanol as the blank for each drug. Absorbance of same concentration solution was measured three times and RSD was calculated.

Table 4: Intraday Precision of NABU at 238.6 nm

Concentration of NABU (µg/ml)	Absor-bance	Mean Absorbance	± SD (n=3)	% RSD
8	0.655	0.656	0.003	0.467
	0.653
	0.659
10	0.805	0.805	0.003	0.372
	0.802
	0.808
12	0.979	0.979	0.008	0.766
	0.987
	0.972
Mean % RSD: 0.537

Table 5: Interday Precision of NABU at 238.6 nm

Concentration of NABU (µg/ml)	Experi-ment Day	Mean Absorb-ance	± SD (n=3)	% RSD
8	DAY 1	0.656	0.003	0.467
	DAY 2	0.649	0.004	0.541
	DAY 3	0.659	0.002	0.231
10	DAY 1	0.805	0.003	0.372
	DAY 2	0.807	0.004	0.446
	DAY 3	0.798	0.004	0.451
12	DAY 1	0.979	0.008	0.766
	DAY 2	0.978	0.010	1.037
	DAY 3	0.984	0.011	1.058
Mean % RSD: 0.596

Table 6: Intraday Precision of NABU at 248.4 nm

Concentration of NABU (µg/ml)	Absorb-ance	Mean Absorb-ance	± SD (n=3)	% RSD
8	0.134	0.134	0.001	0.429
	0.135
	0.134
10	0.165	0.167	0.002	0.916
	0.167
	0.168
12	0.199	0.201	0.003	1.250
	0.201
	0.204
Mean % RSD: 0.865

Table 7: Interday Precision at of NABU 248.4 nm

Concentration of NABU (µg/ml)	Experi-ment Day	Mean Absorb-ance	± SD (n=3)	% RSD
8	DAY 1	0.135	0.001	0.857
	DAY 2	0.136	0.002	1.120
	DAY 3	0.134	0.001	0.931
10	DAY 1	0.167	0.002	0.916
	DAY 2	0.165	0.003	0.606
	DAY 3	0.167	0.002	1.197
12	DAY 1	0.201	0.004	1.492
	DAY 2	0.204	0.002	1.232
	DAY 3	0.202	0.003	1.309
Mean % RSD: 1.073

b) Intra and inter day precision

Intraday precision was determined by analyzing NABU and PCM for three times in the same day at 238.6 nm and 248.4 nm. Inter day precision was determined by analyzing both the drugs daily for three days. Intraday and inter day precision for Nabu at 238.6 and 248.4 nm were found as depicted in Table 4, 5, 6 and 7 and that of PCM were Table 8, 9, 10 and 11.

Table 8: Intraday Precision of PCM at 238.6 nm

Concentration of PCM (µg/ml)	Absorb-ance	Mean Absorb-ance	± SD (n=3)	% RSD
8	0.657	0.654	0.003	0.385
	0.652
	0.654
10	0.802	0.805	0.003	0.379
	0.806
	0.808
12	0.971	0.981	0.006	0.617
	0.983
	0.978
Mean % RSD: 0.460

Table 9: Interday Precision of PCM at 238.6 nm

Concentration of PCM. (µg/ml)	Experi-ment Day	Mean Absorb-ance	± SD (n=3)	%RSD
8	DAY 1	0.654	0.003	0.385
	DAY 2	0.655	0.006	0.920
	DAY 3	0.655	0.007	1.027
10	DAY 1	0.805	0.003	0.379
	DAY 2	0.793	0.004	0.504
	DAY 3	0.803	0.005	0.571
12	DAY 1	0.977	0.006	0.617
	DAY 2	0.977	0.009	0.895
	DAY 3	0.977	0.014	1.419
Mean % RSD: 0.745

Table 10: Intraday Precision of PCM at 248.4 nm

Concentration of PCM (µg/ml)	Absorb-ance	Mean Absorb-ance	± SD (n=3)	% RSD
8	0.811	0.808	0.004	0.468
	0.810
	0.804
10	0.989	0.997	0.008	0.753
	0.997
	1.004
12	1.207	1.207	0.010	0.787
	1.197
	1.216
Mean % RSD: 0.669

Table 11: Interday Precision at of PCM 248.4 nm

Concentration of PCM (µg/ml)	Experi-ment Day	Mean Absorb-ance	± SD (n=3)	% RSD
8	DAY 1	0.808	0.004	0.468
	DAY 2	0.812	0.006	0.739
	DAY 3	0.815	0.007	0.805
10	DAY 1	0.997	0.008	0.753
	DAY 2	0.999	0.012	1.161
	DAY 3	0.992	0.004	0.408
12	DAY 1	1.207	0.010	0.787
	DAY 2	1.209	0.013	1.092
	DAY 3	1.200	0.017	1.430
Mean % RSD: 0.849

c) Reproducibility

Reproducibility test was determined between two analysts and instruments. The value of RSD was to be found below 1 showed reproducible of developed spectrophotometric method. The values obtained were evaluated using t- test to verify their reproducibility and are shown in Table 12.

Accuracy

To ascertain the accuracy of proposed methods, recovery studies were carried out by standard addition method at three different levels (80%, 100% and 120%). The method showed % recovery in range of 98.09 % to 100.22% for nabumetone whereas 99.88% to 101.81% for Paracetamol. The results indicate that developed method is accurate enough for routine use as depicted in Table 13.

Limit of Detection and Limit of Quantification

Calibration curve was repeated 5 times and standard deviation (SD) of intercepts (response) was calculated. Then LOD and LOQ were measured by using mathematical expressions by using equations:

Limit of Detection (LOD): 3.3 × σ/S,

Limit of Quantification (LOQ): 10 × σ /S

Where, σ = The Standard deviation of the response,

S = Slope of calibration curve.

LOD and LOQ were found to be 0.06 and 0.19 µg/ml at 238.6 nm and 0.14 µg/ml and 0.42 µg/ml at 248.4 nm for NABU, respectively. 0.09 and0.27 µg/ml at 238.6 nm and 0.26 µg/ml and 0.89 µg/ml at 248.4 nm for for PCM, respectively.

Table 12: Reproducibility data of NABU and PCM at 10 µg/mL

Variable factor	Condition	Drugs Concentration (µg/mL) (Mean* ± SD)		‘t’ Stat (tcal)	‘t’ Critical (ttab)	Interference
		NABU	PCM
Different analyst	Analyst-1	9.91 ± 0.01	9.85 ± 0.01	0.51	2.93	No Significance Difference
	Analyst-2	9.88 ± 0.02	9.82 ± 0.01
Different instrument	Shimadzu	9.97 ± 0.01	9.87 ± 0.01	1.02	2.92	No Significance Difference
	Elico	9.93 ± 0.02	9.92 ± 0.02

* Average of five determination

Table 13: Determination of Accuracy for Nilitis P

Sample Concentration (µg/ml)		Amount of Standard added (µg/ml)		% Recovery* ± SD
NABU	PCM	NABU	PCM	NABU	PCM
10.0	10.0	8.0	8.0	98.09 ± 0.43	99.88 ± 0.20
10.0	10.0	10.0	10.0	99.88 ± 0.14	101.81 ± 0.31
10.0	10.0	12.0	12.0	100.22 ± 0.21	101.33 ± 0.29

* Average of five determination

Table 14: Analysis of Marketed Formulation

Formulations	Label claim (mg)		Amount found (mg)		% Assay* ± SD
	NABU	PCM	NABU	PCM	NABU	PCM
Nilitis P	500.0	500.0	493.6	508.1	98.72 ± 0.42	101.62 ± 0.26

* Average of five determination

Results of analysis of Marketed formulation

The results of analysis in terms of % label claim was found to be 98.72% ± 0.42 for Nabumetone and 101.62% ± 0.26 for Paracetamol for a formulation analyzed and results are shown in Table 14.

CONCLUSION:

The proposed method is simple, accurate, precise, feasible, sensitive as well as selective and suitable for for determination of Nabumetone and Paracetamol in laboratories. High % recovery (in developed methods) shows that method is free from interference of excipients used in formulation. It could be applied to determination of tablet dosage forms

ACKNOWLEDGEMENT:

The authors are grateful to IPCA Laboratory and Biodeal laboratory, for providing gift samples of Nabumetone and Paracetamol, respectively.

REFERENCE:

1. Current Index of Medical Specialties, Update Prescribers Handbook published by CMP Medica India Pvt. Ltd., Bangalore, 117-119, 263, Jul-Oct 2007.

2. Merck Index, Merck Research Laboratories, division of Merck and company NJ, 13^th ed., pp. 1088, 2001.

3. United State Pharmacopoeia 26, NF 21, pp. 1259, 2003.

4. Indian Pharmacopoeia (4^th ed.), vol.-2, Govt. of India, Ministry of Health and Family Welfare, Controller of Publications, New Delhi. 554, 1996.

5. K. Kobylinska, M. Barlinska and M. Kobylinska, “Analysis of nabumetone in human plasma by HPLC. Application to single dose pharmacokinetic studies”, J Pharm Biomed Anal, vol. 32, pp. 323-28, 2003.

6. E. Mikami, T. Goto, T. Ohno, H. Matsumoto and M. Nishida, “Simultaneous analysis of naproxen, nabumetone and its major metabolite 6- methoxy-2-naphthylacetic acid in pharmaceuticals and human urine by high-performance liquid chromatography”, J Pharm Biomed Anal, vol. 23, no. 5, pp. 917-925, 2000.

7. F. Idrees and Al-Momani, “Determination of Nabumetone and Its Major Metabolite in Plasma and Tablet Formulations by Reverse-Phase HPLC ”, Analytical Letters, vol. 30, no. 14, pp. 2485 – 92, 1997.

8. A. Kumar, B. Anroop and K. S. Vijay, “Spectrophotometric method for the simultaneous estimation of nimesulide and paracetamol in tablet dosage form”, Indian Drugs, vol. 40, no.12, pp. 727-29, 2003.

9. J. F. Sheen, G. R. Her, “Application of pentafluorophenyl hydrazine derivatives to the analysis of Nabumetone and testosterone in human plasma by liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry”, Anal Bioanal Chem, vol. 380, no.7-8, pp. 891-7, 2004.

10. R. Szotak and s. Mazurek, “Quantitative determination of acetylsalicylic acid and paracetamol in tablet dosage form”, The Analyst, vol. 127, pp. 144-48, 2002.

11. P. R. Mahaparle, J. N. Sangshetti, S. V. Deshpande and P. V. Kasture, “Simultaneous spectro-photometric estimation of aceclophenac and paracetamol in tablet dosage form”, Indian J. Pharma. Educ. Res, vol. 41, no. 1, 42-45, 2007.

12. S. Ravishankar, M. Vasudevan and S. Mathew, “Spectrophotometric method for the simultaneous estimation of paracetamol and chlormezanone in formulations”, Indian Drugs, vol. 35, no.5, pp. 306- 8, 1998.

13. M Knochen, J Giglio and B. F. Reis, “Flow injection spectrophotometric determination of paracetamol in tablets and oral solutions”, J. Pharma. Biomed. Anal, vol. 33, 191-7, 2003.

14. V. Nagulwar, Y. Dhurvey, S. Despande, K. Upadhye, S. Bakhle, and R. Wadetwar, “UV Spectroscopic estimation of paracetamol and valdecoxib in tablet dosage fo rm”, Indian J. Pharm. Sci, vol. 68, no. 5, 639-40, 2006.

16. J. T. Franeta, D. Agbaba and S. Eric, “HPLC assay of acetylsalicylic acid, paracetamol, caffeine and Phenobarbital”, Pharmaco, vol. 57, 709-13, 2002.

17. V. M. Shinde and R. Raman, “Simultaneous method for determination of paracetamol and chlormezanone in tablets by RP-HPLC ”, Indian Drugs, vol. 35, no. 8, pp. 521-23, 1998.

18. U. B. Halkar, P. B. Analkope and S. H. Rane, “High performance liquid chromatographic method for the determination of paracetamol, caffe ine and propyphenazone in tablets”, Indian Drugs, vol. 39, no. 5, pp. 293-96, 2002.

19. M. Y. Momin, P. G. Yeole and M. P. Puranik, “RP-HPLC method for the determination of paracetamol and aceclophenac in tablet dosage form”, Ind. J. Pharm. Sci, vol. 68, no.3, pp. 387-89, 2006.

20. A. Karthik, A. Subramanian, N. Udupa, “Simultaneous RP-HPLC estimation of Paracetamol and Domperidone in tablets”, Indian J. Pharm. Sci, vol. 69, no.1, pp. 142-43, 2007.

21. S. Natarajan, B. Raman, “Stability indicating Isocratic HPLC method for simultaneous estimation of Ondasetron Hydrochloride and Paracetamol from tablets dosage”, Indian Drug, vol. 45, no.5, 2008.

22. M. K. Chouksey, A. Kandapur, N. Tyagi, G. Singh, “Simultaneous estimation of Paracetamol, Chlorzoxazone and Diclofenac sodium in solid dosage forms by RP-HPLC ”, Method Indian Drug, vol. 43, no. 3, 2006.

23. B. S. Nagaralli, J. Seetharamappa, B. G. Gowda and M. B. Melwanki, "Liquid chromatographic determination of ceterizine hydrochloride and paracetamol in human plasma and pharmaceutical formulations”, Journal of Chromatography B, vol. 798, no. 1, pp.49–54, 2003.

24. A. Eswaraselvam, “Simultaneous estimation of paracetamol and ibuprofen by RP-HPLC by using same mobile phase for assay and dissolution in tablet dosage form”, I.P.C. Abstracts, pp. 83, 2004.

25. G. Subramanian, Simultaneous RP-HPLC estimation of Tizanidine, Diclofenac potassium and Paracetamol in tablets, Indian J. Pharm. Sci., vol. 66, no.5, pp. 694-96, 2004.

26. A. S. Bhavsar, G. S. Talele, R. A. Fursule and S. J. Surana, “RP-HPLC estimation of paracetamol and valdecoxib in combined dosage form”, Indian J. Pharm. Sci vol. 68, no. 5,pp. 675-77, 2006.

27. C. Celema, J. A. Alluue, J. Prunonosa, C. Peraire and R Obach, “ simultaneous determination of Paracetamol and Chlorpheniramine in human plasma by liquid chromatography tandem mass spectrometery”, Journal of Chromatography Analysis, vol. 870, no.1-2, pp. 77-86, 2000.

27. S Azagvuel and R. Sekar, “Method development and validation for the simultaneous determination of cetrizine dihydrochloride, paracetamol and phenylpropanolamine hydrochloride in tab- lets by capillary zone electrophoresis”, J. Pharm. Biomed. Anal, no. 1-6, 2006.

28. International Conference on Harmonization (1994) Harmonized Tripartite Guideline, Validation Analytical Procedures, Text and Methodology Q2 (R1), ICH, Geneva, Switzerland.

Received on 05.01.2013 Accepted on 05.02.2013

© Asian Pharma Press All Right Reserved

Asian J. Pharm. Ana. 3(1): Jan.-Mar. 2013; Page 09-16