*Corresponding Author:
Sradhanjali Patra University Department of Pharmaceutical Sciences, Utkal University, Vani Vihar, Bhubaneswar - 751 004, India E-mail: [email protected]
Date of Submission 30 May 2006
Date of Revision 9 July 2007
Date of Acceptance 20 December 2007
Indian J Pharm Sci, 2007, 69 (6): 840-841  


A new simple, sensitive spectrophotometric method in UV region has been developed for the estimation of ondansetron in bulk and solid dosage form. It shows maximum absorbance at 310 nm with water. Beer's law obeys in the concentration range of 5-15 µg/ml. Results of the analysis were validated statistically and by recovery studies.


Spectrophotometric method, ondansetron HCL, optical characteristics, recovery study

Ondansetron, which is a specific antiemetic drug, is used in cancer chemotherapy and induced nausea and vomiting [1]. Chemically, it is (±) 1,2,3,9-tetrahydro-9- methyl-3-[(2-methyl-1H-imidazol-1-yl)methyl]-4Hcarbazol- 4-one, monohydrochloride dihydrate [2] is a selective 5HT3 antagonist. It acts both, peripherally on vagal nerve terminals and centrally in the chemoreceptor trigger zone of the area postrema [3].

The drug is white to off white crystalline powder, odourless, soluble in water, methanol and normal saline [3]. Literature survey revealed very few analytical methods which include only HPLC method for the estimation of ondansetron [2]. The authors have developed a simple sensitive and reproducible UV spectrophotometric method for the determination of ondansetron in pure form as well as in dosage forms, which are described in present communication.

All chemicals used were of analytical grade. The commercially available tablets were procured from local market. Spectral and absorbance measurements were made on Shimadzu double beam UV/Vis spectrometer UV 2101.

About 10 mg of pure ondansetron was accurately weighed and dissolved in 10 ml of water. The above stock solution was further diluted with the same to get a working standard solution of 5 to 15 µg/ml. Aliquots of test solution of ondansetron were transferred into a series of 10 ml volumetric flask and the final volume was brought to 10 ml with water. The absorbance was measured at 310 nm against water and the amount of ondansetron present in the sample solution was computed from calibration curve.

The optical characteristics such as Beer’s law limits, Sandell’s sensitivity, Molar extinction coefficient (calculated from the eight measurements containing 3/4th of the amount of upper Beer’s law limits of ondansetron) and correlation were calculated for the methods and the results are summarized in Table 1 and 2.

Parameters Method
Beer’s law limit (μg/ml) 5-15
Molar extinction coefficient (mol-1 cm-1) 15.29×1000
Sandell’s sensitivity (µg/cm2/0.001 absorbance unit) 0.002386
Correlation coefficient (r)1 1.00
Slope (a) 0.042
Intercept (b) -0.006

Table 1: Optical characteristics, precision and accuracy of the proposed method.

Labelled amount(mg) Amount of drugadded (mg) Amount of drug obtained1 (mg) Percentage recovery2
Proposed method
Standarddeviation % Coefficient of variation
Official method Proposed method
8 10 7.8 7.7 98.71 0.7390 0.7454
8 20 7.8 7.8 100.00
8 30 7.9 7.8 98.73    

Table 2: Results of recovery study of ondansetron HCL

The methods were applied for the analysis of the drugs in the tablet formulation. To evaluate the validity and reproducibility of the methods, known amount of pure drug was added to the previously analysed by proposed methods and mean percent recovery was found to be 99.14 respectively. Interference studies revealed that the common excipients and other additives usually present in the dosage form did not interfere in the proposed methods. In conclusion, the proposed methods appear to be economical, simple, sensitive, reproducible and accurate enough for the routine determination of ondansetron in bulk as well as in tablet.


The authors thank M/S Natco Pharma limited, Hyderabad for providing gift sample of ondansetron HCl.