Simultaneous Estimation of Ebastine and Montelukast sodium in Tablet Dosage Form by Uv-Spectrophotometry and First Order Derivative

A simple, precise, accurate and reproducible spectrophotometric method has been developed forsimultaneous estimation of ebastine and montelukast sodium by employing first order derivative zerocrossing method in methanol and water. The first order derivative absorption at 234 nm (zero crosspoint of ebastine) was used for quantification of montelukast sodium and 281.60 nm (zero cross point ofmontelukast sodium) for quantification of ebastine. The linearity was established over the concentrationrange of 5-25 ?g/mL for both ebastine and montelukast sodium with correlation coefficient r2 0.997 and0.998, respectively. The mean % recoveries were found to be in the range of 102.8 103.2 % and 101- 105 % for ebastine and montelukast sodium, respectively. The proposed method has been validatedas per ICH guideline and successfully applied to the estimation of ebastine and montelukast sodium intheir combined tablet dosage form.