[Passage into normal salivary, lacrimal and nasal secretions of ampicillin and erythromycin administered intramuscularly].

The authors have measured, with the agar diffusion technique, the antibiotic concentrations in the serum as well as in the normal nasal, lachrymal and salivary secretions, after an intramuscular injection of 500 mg of ampicillin and of 200 mg of erythromycin. Bacillus subtilis is used as test germ for dosage of ampicillin and Sarcina lutea for the dosage of erythromycin. An important quantity of ampicillin (0.5 to 2.5 microgram/ml) passes into the nasal secretion. Its passage into the saliva is very irregular and is usually very slight. Bacillus subtilis is not suitable for systematically studying the ampicillin concentration in the lachrymal secretion, which displays a strong, inherent inhibitory effect on this micro-organism. Important concentrations of erythromycin are found in the three secretions: 0.5 to 3.25 microgram/ml in the nasal mucus and in the lachrymal secretion, 0.3 to 4.5 microgram/ml in saliva.