INTRODUCTION:

Meloxicam is a new nonsteroidal anti-inflammatory drug (NASID) developed for the treatment of rheumatoid arthritis and osteoarthritis. It is one of the oxicam derivatives and posses analgesic and antipyretic activity. It is chemically 4-hydroxy-2-methyl-N-(5-methyl-1,3-thiazol-2yl)-2H-1,2-benzothiazine-3-carboxamide-1,1-dioxide¹. Literature survey revealed few chromatographic methods^2-4 and specrophotometric methods^5-6for the estimation of Meloxicam in bulk drug and biological samples. The objective of this investigation is to develop a simple, accurate and reproducible visible spectroscopic method.

EXPERIMENTAL:

Instrument:

Schimadzu-1201-U.V. Spectrophotometer matched glass cells of 1cm path length.

Reagents:

1) Standard stock solution (1mg/ml) : A stock solution of drug was prepared by dissolving accurately weighed 50mg of Meloxicam in 50ml chloroform.

2) Chloroform AR

3) 0.04% W/V Bromocresol green solution and phthalate buffer of pH 1.6 were prepared as per I.P ⁷.

Procedure:

Preparation of calibration curve:

10ml of standard stock solution was diluted to 50ml with chloroform to produce 200mcg/ml (Stock solution II). Aliquouts of 0.5ml-2.5ml of stock solution II were taken in five separating funnels and volume was made up to 10ml with chloroform.To the each separating funnel 5ml of dye solution (0.04%) and 5ml of buffer (pH 1.6) were added and contents were extracted. The lower chloroform layer was collected and diluted to 10ml with chloroform to produce concentration in the range of 10-50 mcg/ml. Absorbance of each resulting solution was measured at 415nm against reagent blank and absorbance was plotted versus concentration to get the calibration curve.

Preparation of sample:

Twenty tablets were weighed and average weight was determined. An accurately weighed tablet powder equivalent to 25mg of Meloxicam was transferred into 25ml volumetric flask, dissolved with little chloroform and then volume was made up to the mark with chloroform. This solution was then filtered using whatmann filter paper (Grade-I). 10ml of this filtrate was diluted to 50ml with chloroform to get 200mcg/ml (Stock solution II). 1ml of this solution was transferred into a separating funnel and volume was made up to 10ml with chlroform.To the each separating funnel 5ml of dye solution (0.04%) and 5ml of buffer (pH 1.6) were added and contents were extracted. The lower chloroform layer was collected and diluted to 10ml with chloroform. The same procedure was repeated with the standard solution of drug at the same concentration (20mcg/ml). The absorbance of each resulting solution was measured at 415nm against reagent blank.

Table 1. Optical characteristics and precision

Parameters	Proposed method
λmax	415nm
Beer’s law range(mcg/ml)	10-50
Sandell’s sensitivity (µg/cm²/0.001 absorbance unit)	0.1612
Molar absorptivity(mole^-1cm^-1)	2.17x10³
LOD(mcg/ml)	0.29
LOQ(mcg/ml)	0.88
Stability	90 mts
*Regression equation(Y^)** Slope Intercept Correlation coefficient	0.0062 -0.0002 0.9999

Y^*= b+aC; where ‘C’ is concentration in mcg/ml and Y is absorbance unit.

Table 2 : Results of analysis in marketed formulations

Formulations

Parameters

%Labelled claim^*

%Recovery^*

M-CAM

Mean

±SD

%RSD

99.86

0.32

0.413

99.62

0.88

MUVERA

Mean

±SD

%RSD

97.93

0.32

0.33

100.4

0.76

* Mean of five determinations SD-Standard deviation, RSD-Relative standard deviation

RESULTS AND DISCUSSION:

The λmax of Meloxicam was found to be 415nm from its spectrum. It showed linearity in the concentration range of 10-50 mcg/ml. The molar absorptivity was found to be 2.17x10³(mole^-1cm^-1) and sandell’s sensitivity was 0.1612 (µg/cm²/0.001 absorbance unit). The correlation coefficient (r) was found to be 0.9999. The LOD and LOQ values were determined from the slope of linearity plot and standard deviation of Y-intercept and found to be 0.88 and 2.69 mcg/ml respectively. The stability of colour of resulting solution was determined by measuring the absorbance at 415nm at 15mts time intervals. There was no considerable change in the absorbance at this wavelength upto 90 minutes. Commercial formulations containing Meloxicam were analyzed by proposed method. Five replicate analysis of the formulation were carried out and mean assay values in tablet formulation M-CAM and MUVERA were found to be 99.86±0.32 and 97.93±0.32. The corresponding RSD values were found to be 0.413% and 0.330% indicating that the method has required precision. The accuracy of the method was determined by recovery studies. Pure Meloxicam was added (5mg) to the preanalysed tablet powder and the mean recovery of Meloxicam was found to be 99.62±0.88 and 100.4±0.768 indicating that the method has required accuracy. The validation results were given in table 1 and 2.

CONCLUSION:

Thus, the developed method is simple, accurate, precise, reproducible, less time consuming and effective. Hence, it can be used for routine analysis of Meloicam in bulk and pharmaceutical formulations.

ACKNOWLEDGEMENTS:

The authors extend their sincere thanks to Unichem Pharmaceuticals Lab Ltd, for providing gift sample of pure Meloxicam. We also extend our thanks to Chairman, K.M College of pharmacy, Madurai -107, for providing the necessary facilities.

REFERENCES:

1. Martindale, The extra pharmacopoeia, The complete drug reference. 32^nd edition; pharmaceutical press. 1999; 52.

2. Joseph-charles J, Bertucat M. Determination of meloxicam in tablet formulations by ultra-violet spetrophotometry and HPLC method. M Anal Lett. 1999; 32(10): 2051-2059.

3. 3.Velpandian T, Jaiswal J, Bharadwaj RK, Gupta SK. Development and validation of a new HPLC estimation of meloxicam in biological samples. J Chromatogr B: Biomed Sci Appl. 2000; 738(2): 431-436.

4. Joseph-charles J, Bertucat M. Simultaneous HPLC analysis of meloxicam in pharmaceutical preparations. J Liq Chromatogr Relat Technol. 1999; 22(13): 2009-2021.

5. Garcia MS, Pedreno CS, Albero MI, Marti J. Spectrophotometric methods for determinating meloxicam in pharmaceuticals usning batch and flow- injection procedure. Eur J Phram Sci. 2000; 9(3): 311-316.

6. Sane RT, Surve V, Francis M. Extractive colorimetric determination of meloxicam from its pharmaceutical preparation. 2000; 37(8): 390-393.

7. Indian Pharmacopoeia, Vol. 2 . Delhi: Controller of publication ; 1996. A-144.

Received on 17.07.2009 Modified on 14.09.2009

Asian J. Research Chem. 2(4):Oct.-Dec. 2009 page 467-468