Spectrophotometric methods for the determination of Ibuprofen in tablets.

Ibuprofen in film coated tablets of different strengths has been determined using different spectrophotometric methods. These are: (i) the compensation method, (ii) a two wavelengths method, (iii) second-order and (iv) fourth-order derivative methods, and (v) a curve fitting method based upon computing the quadratic coefficient of the orthogonal polynomials expansion of its benzenoid absorption characteristics. All results were compared with the HPLC method of the B.P. 2003 using paired comparison. Developed methods have been validated and applied to different tablet formulations. Mean differences from the B.P. method were found to be -0.10, -0.30, -0.10, -0.16, -0.34%, respectively. In view of the relatively low specific absorbance of ibuprofen in the ultraviolet region [A (1%, 1 cm) =18.5 at 264 nm] its accurate and precise determination in different tablet formulations is challenging due to the presence of interferences from excipients.