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BioMed Research International
Volume 2013 (2013), Article ID 392010, 5 pages
Research Article

Comparative Plasma Exposure and Lung Distribution of Two Human Use Commercial Azithromycin Formulations Assessed in Murine Model: A Preclinical Study

1Laboratory of Pharmacology, Faculty of Veterinary Medicine, Universidad Nacional del Centro de la Provincia de Buenos Aires, Paraje Arroyo Seco s/n., 7000 Tandil, Argentina
2Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Argentina
3Tandil Veterinary Research Center (CIVETAN-CONICET), Argentina

Received 30 April 2013; Revised 3 July 2013; Accepted 24 July 2013

Academic Editor: Kazim Husain

Copyright © 2013 Virginia Rivulgo et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Azithromycin (AZM) therapeutic failure and relapses of patients treated with generic formulations have been observed in clinical practice. The main goal of this research was to compare in a preclinical study the serum exposure and lung tissue concentration of two commercial formulations AZM-based in murine model. The current study involved 264 healthy Balb-C. Mice were divided into two groups ( ): animals of Group A (reference formulation -R-) were orally treated with AZM suspension at 10 mg/kg of b.w. Experimental animals of Group B (generic formulation -G-) received identical treatment than Group A with a generic formulation AZM-based. The study was repeated twice as Phase II and III. Serum and lung tissue samples were taken 24 h post treatment. Validated microbiological assay was used to determine the serum pharmacokinetic and lung distribution of AZM. After the pharmacokinetic analysis was observed, a similar serum exposure for both formulations of AZM assayed. In contrast, statistical differences ( ) were obtained after comparing the concentrations of both formulations in lung tissue, being the values obtained for AUC and Cmax (AZM-R-) +1586 and 122%, respectively, than those obtained for AZM-G- in lung. These differences may indicate large differences on the distribution process of both formulations, which may explain the lack of efficacy/therapeutic failure observed on clinical practice.