Spectrophotometric Determination of Cilostazol in Tablet Dosage Form

Purpose: To develop simple, rapid and selective spectrophotometric methods for the determination of cilostazol in tablet dosage form. Methods: Cilostazol was dissolved in 50 % methanol and its absorbance was scanned by ultraviolet (UV) spectrophotometry. Both linear regression equation and standard absorptivity were calculated and both methods were validated as per ICH guidelines. Cilostazol was determined in tablet dosage form using these validated methods. Results: The lambda(max) of cilostazol was 258.2 nm in 50 % methanol. Beer-Lambert's law was obeyed in the concentration range of 0 - 25 mu g/ml and standard absorptivity was 420.2 dL.g(-1).cm(-1). The numerical values for all the validation parameters were within acceptable limits. The results of cilostazol tablet determination by linear regression equation and standard absorptivity methods indicate purity of 100.0 - 102.4 and 98.7 - 101.1 % with standard deviations of 0.611 and 0.592, respectively. Comparing the methods at 99 % confidence limit, the F-test value was found to be 1.065. Conclusion: These validated methods may be useful for routine analysis of cilostazol as bulk drugs, in dosage forms as well as in dissolution studies in the pharmaceutical industry.