Transport of antibiotics into the canine sinus. Experiments with penicillin G and erythromycin.

Complete and consistent occlusion of the nasofrontal duct of the canine sinus was achieved by introducing acrylic through a trephinated opening in the nasal dorsum. This surgical procedure resulted in the isolation of the frontal sinus, without impairing the integrity of the cavity. In this experimental canine model, potassium penicillin G and erythromycin lactobionate were absorbed into the blood equally well when placement was either in the intramuscular (IM) space or in frontal sinus cavity. When different concentrations of these antibiotics were injected into the IM space, peak blood levels occurred between one and two hours; however, peak sinus levels, following IM introduction, did not occur until four hours. The peak ratios show that between 4% and 20% of penicillin, and 1% and 12% of erythromycin in the blood is transferred across the normal sinus membrane.