Determination of ciprofloxacin and levofloxacin in human sputum collected from cystic fibrosis patients using microextraction by packed sorbent-high performance liquid chromatography photodiode array detector

• MEPS–HPLC–PDA detection of ciprofloxacin and levofloxacin in human sputum.
• First report for levofloxacin analysis in sputum after IV and OS administration.
• HPLC analyses of sputum samples collected from cystic fibrosis patients.
• Easy and fast detection of biological samples through MEPS–HPLC–PDA procedure.
• Validation procedure of biological samples according to ICH Q2(R1) guidelines.

This paper reports a new, easy, cheap, and fast MEPS–HPLC–PDA method for the simultaneous analysis of ciprofloxacin and levofloxacin, two fluoroquinolones (FLQs) commonly used for the treatment of pulmonary infections in cystic fibrosis (CF) patients. The FLQs were resolved on a Discovery C8 column (250 mm × 4.6 mm; 5 μm particle size) using an isocratic elution with a run time of 15 min, without further purification. The method was validated over concentrations ranging from 0.05 to 2 μg/mL for both analytes in human sputum, and enrofloxacin was used as internal standard.This method was successfully tested to detect FLQs in sputum collected from CF patients. The MEPS–HPLC–PDA method was validated using biological samples collected from CF patients orally or intravenously injected with FLQs. The resultant data showed that the method is selective, sensitive and robust over range of concentrations for both FLQs. The limit of quantification of the method was 0.05 μg/mL for both analytes (comparable to more complex and expensive instrument configurations), weighted-matrix-matched standard curves showed a good linearity up to 2 μg/mL, and parallelism tests were also successfully assessed. The intra- and inter-day precision (RSD%) values were ≤10.4% and ≤11.1%, respectively, for all range of analysis. The intra- and inter-day trueness (Bias%) values are ranged from −11.8% to 7.25% for both antibiotic drugs.At the best of our knowledge, this is the first MEPS–HPLC–PDA based method that uses MEPS procedure for simultaneous determination of ciprofloxacin and levofloxacin in human sputum. The method was tested successfully on real sputum samples by following a conventional drug administration. Furthermore, the MEPS–HPLC–PDA based method provides more advantages to detect and analyze quickly the antibiotic drugs in biological matrices than other analytical procedures reported in literature.