METHOD DEVELOPMENT AND VALIDATION FOR SIMULTANEOUS ESTIMATION OF ASPIRIN AND LANSOPRAZOLE IN BULK AND LABORATORY SAMPLE BY DIFFERENT UV SPECTROPHOTOMETRIC TECHNIQUES

Four simple, rapid, inexpensive, precise and accurate UV spectrophotometric methods have been developed for simultaneous estimation of Aspirin (ASP) and Lansoprazole (LANSO). Method A was Simultaneous equation method (Vierodt's method) which applies measurement of absorptivities at two wavelengths, 276.00 nm, (lambda(max) of Aspirin) and 284.00 nm, (lambda(max) of Lansoprazole) in zero order spectra. The concentrations were calculated from the derived equations. Method B was based on zero crossing first Derivative (D1) spectrophotometry where Aspirin showed zero crossing point at 303nm and Lansoprazole showed zero crossing point at 244.5nm. Method C was Dual wavelength technique, in which absorbance difference between two points on the mixture was measured where difference for one drug is zero and amplitude of other drug was directly proportional to the concentration. Analytical wavelengths for Aspirin were 262nm and 295.7nm; while for Lansoprazole 270nm and 282.5nm were selected. Method D was based on Multicomponent mode technique, in which sampling wavelengths selected were 276 and 284 nm. Linearity for Aspirin was between 26-130 mu g/mL and Lansoprazole was 4-20 mu g/mL. Accuracy of all above methods was determined by recovery studies and % recovery was estimated between 97 to 103%. Intraday and inter day precision was checked for all methods and mean %RSD was found to be less than 2. These methods were successfully applied for estimation of Aspirin and Lansoprazole in laboratory sample. Statistical Analysis was done to compare all the four developed spectrophotometric methods.