Modified release pharmaceutical formulations containing active principles having antibiotic activity

Formulations based on substances endowed with antibiotic activity for the preparation of oral hydrophilic matrixes (modified release tablets). Said hydrophilic matrixes can release the carried antibiotic gradually and following a release profile which can be established by suitable in vitro tests. An essential feature of said hydrophilic matrixes consists in that they can provide a high bioavailability characterized by such extended effective plasmatic levels to enable only one or two daily administrations, thus simplifying dosage and correct use by the patient.