DEVELOPMENT AND VALIDATION OF NEW SPECTROPHOTOMETRIC PROCEDURES FOR THE ANALYSIS OF ROXITHROMYCIN IN BULK AND DOSAGE FORMS

Novel sensitive spectrophotometric techniques were developed and validated for a quantitative estimation of roxithromycin (ROX) in bulk and pharmaceuticals. In alkaline medium, procedure (A) was performed by ion-pairs formation between the studied macrolide and 1,2-naphthoquinone-4-sulphonate to formed orange - products with maxima absorption at 454 nm. While the second method (B) was carried out for coupling the amino group of the cited macrolide with phylloquinone using the charge transfer reaction to form coloured products with λmax at 457 nm. The methods presented good linearity in the range of concentrations between 1.0 - 28.8 μg/mL. Regression coefficients were 0.9997 and 0.9998 for methods (A) and (B), respectively, as well the detection limits were cited in 0.26-0.23 μg/mL. Validation measurements were rebuts, accurate and precise within %RSD values lower than 3.5%. These methods were successfully used to investigate roxithromycin quantitatively in tablets. Recoveries were 98.94–101.01% and no interferences were detected from excipients. Both procedures are rapid, simple and cost-effective and it can adopted quality control application of this antibiotic.