RESUMO
OBJECTIVES: Simple, specific, accurate, precise, sensitive, and cost effective spectrophotometric methods were developed and validated for quantification of the drugs lornoxicam (LOR) and mesalamine (MES) in pure form and in pharmaceutical formulations. MATERIALS AND METHODS: A Shimadzu UV-1800 double-beam UV-Visible spectrophotometer having a spectral bandwidth of 0.1 nm with wavelength accuracy ±0.1 nm with a pair of 1 cm path length matched quartz cells was used to measure the absorbance of the resulting solution. Method I was used for the quantification of LOR, based on measurement of the absorbance of bluish green chromogen complex at 760 nm, which is formed by the reaction of LOR with ferric chloride and potassium ferricyanide (redox technique). Method II was used for the quantification of MES, based on measurement of the absorbance of yellow chromogen at 400 nm, which is formed by the condensation reaction of the primary amino group of MES with salicylaldehyde reagent (SA) (Schiff base formation). RESULTS: Both methods obeyed Beer's law in the concentration range of 0.5-4.5 µg/mL and 0.2-1.7 µg/mL with good correlation coefficients of 0.9974 and 0.998 for methods I and II, respectively. CONCLUSION: The developed method is simple, sensitive, and specific, which was validated statistically as per ICH guidelines, and can be used in the routine analysis of LOR and MES in pharmaceutical dosage forms.
