CENTRO DE INVESTIGACION Y DESARROLLO EN CIENCIAS APLICADAS "DR. JORGE J. RONCO"
Unidad Ejecutora - UE
congresos y reuniones científicas
Development and validation of a HPLC-UV method for determination of Levofloxacin in lung tissue. Application to the quantification of the drug after nasal administration into biopolymeric microparticles
MARÍA ESPERANZA RUIZ; JUAN FRANCISCO MORALES; ANDREA ENRIQUE; MARÍA LAURA SBARAGLINI; ALAN TALEVI; GERMAN ISLAN; MAXIMILIANO CACICEDO; LUIS BRUNO-BLANCH; GUILLERMO CASTRO
Congreso; 3ra Reunión Internacional de Ciencias Farmacéuticas - RICIFA 2014-; 2014
A HPLC-UV method for determination of Levofloxacin (LFX) in mouse lung tissue was developed and validated. Conditions: C18 column, acetonitrile/KH2PO4 30 mM pH 2.80 (22/78) mobile phase, 1.0 ml/min and 300 nm detection. Enrofloxacin (EFX) was used as internal standard (IS). For sample preparation, excised mouse lungs were homogenized, spiked with IS and diluted in 2 ml of physiologic solution. After 24 hs at 4 °C, two 0.9 ml-aliquots were extracted with 2 ml of dichloromethane and centrifuged. The organic layer was separated and evaporated to dryness, and the residue resuspended with 200 μl of mobile phase prior to injection. In an initial validation stage, samples were prepared in blank homogenized lung tissue by the addition of known concentrations of LFX and EFX in methanolic solution, and linearity, precision, accuracy, limit of quantification (LQ), specificity and stability were assessed. The response was linear in the range 0,02 (LQ) ? 15.00 μg/ml. Precision RSD values were < 4.0% and accuracy was between 90?100%. The method was specific to the biological matrix, and the drugs were stable in methanolic solution, biological matrix and prepared samples. The recovery was around 70% due to the drug loss in the lung tissue, since the extraction procedure had a 95-100% recovery. Microparticles were prepared by co-precipitation of CaCO3 in presence of the alginate biopolymer. The obtained hybrid microparticles showed narrow size dispersion around 5 μm, an ideal size for pulmonary delivery. LFX was incorporated by absorption, reaching a loading of 40.0 µg per mg of matrix. Therefore, in a second validation stage, all validation parameters were re-assessed using these microparticles instead of the methanolic solution, and similar results were obtained. Finally, the method was successfully applied to the quantification of LFX in mouse lungs after the nasal administration of the polymeric microparticles.