Spectrophotometric Estimation Of Clopidogrel Bisulphate

Int. J. Chem. Sci.: 7(1), 2009, 216-218

SPECTROPHOTOMETRIC ESTIMATION OF CLOPIDOGREL BISULPHATE IN PHARMACEUTICAL DOSAGE FORMS NAYANA PIMPODKARa∗∗, YOGITA SHETE, N. S. MAHAJANa, Y. V. PORE, R. L. JADHAVa and B. S. KUCHEKAR a

Government College of Pharmacy, Vidyanagar, KARAD – 415214, Dist., Satara (M. S.) INDIA Department of Pharmaceutical Chemistry, Satara College of Pharmacy, SATARA (M. S.) INDIA

ABSTRACT A simple, sensitive, rapid, accurate and precise spectrophotometric method has been developed for estimation of clopidogrel bisulfate in bulk and pharmaceutical dosage forms. clopidogrel bisulfate shows maximum absorbance at 270 nm with molar absorptivity of 848.3 × 103 L/mol. cm. Beer’s law was obeyed in the concentration range of 50 – 500 µg/mL. Results of analysis were validated statistically and by recovery studies. Key words : Clopidogrel bisulfate, Spectrophotometric method.

INTRODUCTION clopidogrel bisulfate is chemically known as methyl (+)-(S)-α-(2-chlorophenyl) -6, 7-dihydrothieno [3, 2-c] pyridine-5(4H)-acetate sulfate (1 : 1). It is a new thienopyridine derivative chemically related to ticlopidine1,2 It prevents ischemic stroke, myocardial infraction and vascular disease and is indicated for the reduction of atherosclerotic events3, 4. It is official in Merck index and Martindale. Only HPLC methods are reported for estimation of clopidogrel bisulphate in formulation and its metabolites in plasma and serum. Gas chromatographic determination of clopidogrel from tablet dosage forms has been reported5-7. The objective of this study was to develop simple, rapid, accurate and specific spectrophotometric method for the estimation of clopidogrel bisulfate using UV spectrophotometer. The simple method was developed using solvent distilled water with ∗

Author for correspondence; E-mail: [email protected]

217

Int. J. Chem. Sci.: 7(1), 2009

minimum processing steps. The λmax of clopidogrel bisulfate in 0.1N H2SO4 was found to be 270 nm and Beer’s law was obeyed in the range of 50–500 µg/mL. The result of analysis was validated statistically and by recovery studies; thus, this method of estimation of clopidogrel bisulfate was found to be simple precise and accurate.

EXPERIMENTAL A Shimadzu 1700 UV spectrophotometer with 1 cm matched cuvetts was used for estimation. Standard solution of drug, 1000 µg/mL was prepared in 0.1N H2SO4 Sample solution: Twenty tablets of clopidogrel bisulfate were weighed and powered in glass mortar. Amount equivalent to 20 mg was transferred to 100 mL volumetric flask, dissolved and made up the volume with 0.1N H2SO4 Aliquots of 1 to 10 mL portions of standard solution were transferred to a series of 10 mL Corning test tubes and volume in each test tube was adjusted to 10 mL with 0.1N H2SO4. The absorbance of solutions was measured at 270 nm against 0.1N H2SO4 as a blank and calibration curve was constructed. Similarly, absorbance of sample solution was measured and amount of clopidogrel bisulfate was determined by referring to the calibration curve. Recovery studies were carried out by adding a known quantity of pure drug to the preanalyzed formulation and the proposed method was followed. From the amount of drug found, percentage recovery was calculated.

RESULTS AND DISSCUSION The proposed method of determination of clopidogrel bisulfate showed molar absorptivity of 848.3 × 103 L/mol. cm and Sandell’s sensitivity 0.4949 mcg/cm2/0.001absorbance units. Linear regression of absorbance on concentration gave the equation y = 0.00202 x + 0.00373 with a correlation coefficient of 0.9998. Relative standard deviation of 0.14232 was observed for analysis of three replicate samples, indicating precision and reproducibility. clopidogrel bisulfate exhibits its maximum absorption at 270 nm and obeyed Beer’s law in the range of 50 – 500 µg/mL. The results of analysis and recovery studies are presented in the Table 1. The percentage recovery value 99-100% indicates that there is no interference from the excipients present in formulation. The developed method was found to be sensitive, accurate, precise and reproducible and can be used for the routine quality control analysis of clopidogrel bisulfate in bulk drugs and formulations.

218

N. Pimpodkar et al.: Spectrophotometric….

Table 1 : Results of analysis and recovery studies Formulations

Label Claim

% Estimated

S. D.

C. O. V. (%)

S. E.

% Recovery

Tab 1

75

99.42

0.81

0.82

0.47

100.47

Tab 2

75

100.49

1.20

1.19

0.69

99.48

Tab 3

75

100.20

0.90

0.90

0.52

99.73

S. D : Standard Deviation, S. E. : Standard Error, C. O. V. : Coefficient of Variation

ACKNOWLEDGEMENTS We are grateful to Torrent Pharmaceutical Ltd., Mehsana, Gujarat, for providing gift sample of drug for research work. We are also thankful to Principal, Govt. College of Pharmacy, Karad for providing laboratory facility and constant encouragement.

REFERENCES 1.

S. Budavari, The Merck Index, Merck and Co. Inc., White House Station. NJ, 12th Edn, (1996) p. 2456.

2.

K. S. Kallahan, A. R. Gennaro and Remington, The Science and Practice of Pharmacy, 20th Edn, Vol. II, Lippincott Williams and Wilkins, Philadelphia (2000) p. 1259.

3.

CAPRIE Steering Committees, Lancet, 348, 1329 (1996).

4.

K. Moshfegh, M. Redondo, F. Julmy, W. A. Wuillemin, M. U. Gebauer, A. Haeberli and B. J. Meyer, J. Amer. Coll. Cardial., 36, 699 (2000).

5.

A. Mitakos and J. Panderi, J. Pharm Biomed. Anal, 28, 431 (2002).

6.

P. Lagorce, Y. Perez, J. Ortiz, J. Necciari and F. Bressole, J. Chromatogr. Biomed. Appl., 720, 107 (1988).

7.

N. S. Kamble and A. Venkatachalam, Indian J. Pharm. Sci., 64, 128 (2005).

Revised : 25.10.2008

Accepted : 01.11.2008