SIMULTANEOUS ESTIMATION OF MOXIFLOXACIN HCL AND PREDNISOLONE ACETATE FROM EYE DROPS

Moxifloxacin HCl (MOX) and Prednisolone acetate (PRD) are combined in ophthalmic formulations to provide antibacterial and anti-inflammatory activity, respectively. The present study describes the development and validation of two simple UV-visible spectrophotometric procedures for their simultaneous estimation in bulk drug mixtures and eye-drop formulation. A Shimadzu UV-1800 spectrophotometer was used. Standard solutions were prepared in methanol and diluted with distilled water. Overlain spectra were used to select analytical wavelengths. For the simultaneous-equation method, 288 nm and 247 nm were selected as the respective λmax values of MOX and PRD. Both analytes showed linear responses over 2–12 µg/mL. Specific absorptivity values were established and used to construct simultaneous equations for calculation of both components. For the Q-absorbance-ratio method, the thesis reports an isoabsorptive wavelength in the vicinity of 273–277 nm; the method was applied together with the individual drug maxima. The methods were assessed using assay, recovery, intra-day precision, inter-day precision, repeatability and ruggedness. In the marketed eye-drop sample, the simultaneous-equation procedure gave 99.93% of label claim for MOX and 100.77% for PRD, while the Q-absorbance-ratio procedure gave 100.44% and 101.01%, respectively. Recovery for the simultaneous-equation method was reported as 100.44% for MOX and 100.11% for PRD; the Q method gave 100.25% and 99.90%, respectively. Reported precision values were below 2% RSD. The study therefore demonstrates that both procedures can be used for routine simultaneous assay of the selected ophthalmic combination where UV spectrophotometric analysis is appropriate.