Simple spectrofluorimetric and microbiological assay methods for the estimation of ofloxacin in biological fluids

Objective: To evolve simple methods for the assay of ofloxacin in biological fluids. Methods: Simple methods for the estimation of ofloxacin in plasma, saliva and urine employing microbiological assay using plate diffusion technique and by fluorimetric method based on the measurement of native fluorescence emitted by ofloxacin, have been described. Results: The recovery of ofloxacin from all the three biologial fluids was 93-98% and the sensitivity was 0.5 μg/ml on all 5 different occasions by both the methods. Anti-TB drugs viz., rifampicin, ethambutol, isoniazid and pyrazinamide and also anti-leprosy drugs viz., dapsone and clofazimine at concentrations of 10 and 20 μg/ml did not interfere with the estimation of ofloxacin by either method. Ofloxacin is stable in biological fluids for a period of at least 8 days at -20°C. Conclusion: Both the methods described are simple, involve very few steps and do not need either costly chemicals or sophisticated equipments