Spectrophotometric Estimation Of Escitalopram Oxalate

Int. J. Chem. Sci.: 7(1), 2009, 235-237

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

Government College of Pharmacy, Vidyanagar, KARAD – 415214 (M. S.) Dist. Satara 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 escitalopram oxalate in bulk and pharmaceutical dosage forms. Escitalopram oxalate shows maximum absorbance at 284 nm with molar absorptivity of 2.249 × 103 L/mol. cm. Beer’s law was obeyed in the concentration range of 20-120 µg/mL. Results of analysis were validated statistically and by recovery studies. Keywords : Escitalopram oxalate, Spectrophotometric method

INTRODUCTION Escitalopram oxalate is chemically known as S (+)-1-[3-(dimethyl-amino) propyl]1-(p-fluorophenyl) - 5- phthalancarbonitrile and it is an orally administered selective serotonin reuptake inhibitor. (SSRI)1. It is indicated for major depressive disorders and generalized anxiety disorders2,3. It is official in Merck index and Martindale. Only chromatographic methods have been developed for estimation of the drug. No ultraviolet method has been reported for estimation of drug in pharmaceutical dosage form4. The objective of this study was to develop simple, rapid, accurate and specific spectrophotometric method for the estimation of escitalopram oxalate using UV spectrophotometer. The simple method was developed using solvent distilled water with minimum processing steps. The λmax of escitalopram oxalate in distilled water was found to be 284 nm and Beer’s law was obeyed in the range of 20-120 µg/mL. The result of analysis was validated statistically and by recovery studies; thus, this method of estimation of ∗

Author for correspondence; Email : [email protected]

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Y. Shete et al.: Spectrophotometric….

escitalopram oxalate was found to be simple, precise and accurate.

EXPERIMENTAL A Shimadzu 1700 UV spectrophotometer with 1 cm matched cuvettes was used for estimation. Standard solution of drug, 200 µg/mL was prepared in distilled water. Sample solution: Twenty tablets of escitalopram oxalate 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 distilled water. 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 distilled water. The absorbance of solutions was measured at 284 nm against distilled water as a blank and calibration curve was constructed. Similarly, absorbance of sample solution was measured and amount of escitalopram oxalate 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 escitalopram oxalate showed molar absorptivity of 2.249 × 103 L/mol. cm and Sandell’s sensitivity 0.18426 mcg/cm2/0.001absorbance units. Linear regression of absorbance on concentration gave the equation y = 0.00542 x + 0.01373 with a correlation coefficient of 0.9995.Relative standard deviation of 0.00104 was observed for analysis of three replicate samples, indicating precision and reproducibility. Table 1 : Results of analysis and recovery studies Formulations

Label claim

% Estimated

S. D.

C. O. V. (%)

S. E.

% Recovery

Rescita 20

20

100.57

0.08

0.08

0.04

100.8

Nexito 10

10

101.08

0.77

0.77

0.45

99.9

Szetalo 10

10

99.6

0.67

0.68

0.39

99.9

S. D. : Standard deviation, S. E : Standard error, C. O. V. : Coefficient of variation

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Int. J. Chem. Sci.: 7(1), 2008

Escitalopram oxalate exhibits its maximum absorption at 284 nm and obeyed Beer’s law in the range of 20-120 µg/mL. The results of analysis and recovery studies are presented in the Table 1. The percentage recovery value 99-101%, which 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 escitalopram oxalate in bulk drugs and formulations.

ACKNOWLEDGEMENTS We are grateful to Sun Pharmaceuticals India Ltd, Ankleshwar for providing gift sample of drug for research work. We thank the Principal, Govt. College of Pharmacy, Karad for providing laboratory facility and constant encouragement.

REFERENCES 1.

S. C. Sweetman, (Eds.) Martindale : The Complete Drug Reference, 33rd Edn., The Pharmaceutical Press, London (2000) p. 281.3

2.

http: //www. rxlist. com/cgi/generic/lexapro_cp. htm

3.

G. Ursula and M. R. Katharina, Clinical Chemistry and Laboratory Medicine (2003) 12, 41, 1571.

4.

www. ncbi. nlm. nih. gov/entrez/query. fcgi?cmd=Retrieveanddb=pubmedlistuids=15522722anddopt=Abstract citalopram Escitalopram Lexapro.

Revised : 25.10.2008

Accepted : 01.11.2008