The usual dosage for the chronic treatment of acne is 1 capsule (300 mg) daily: treatment should be continued for at least 8 weeks. For other infections, the usual dosage is 1 capsule b.d. If higher doses are required, 3-4 capsules may be given over 24 hours. Lower doses may be given for prophylaxis.

The concentration of lymecycline in serum, extracts or tissue pieces was determined by using a microbiological assay for tetracycline. A spore suspension of Bacillus cereus ATCC 11778 incorporated in PDM agar, pH 6.6 (AB Biodisk, Stockholm) was used. The analyses of solid tissue pieces (”punch method”) were performed on the same type of plate. They were rinsed for excess of blood in phosphate-buffered saline and gently blotted between filter papers. The tubal tissue was sectioned longitudinally, thus allowing separation of the serosa from the mucosa with its muscular coat. Some 6- 10 pieces of each tissue were punched out using a metal cylinder 5 mm in diameter. The pieces were weighed on a microbalance and pieces weighing 10- 30 mg were chosen for the analyses. These were applied directly on the preseeded agar plates which were left at room temperature, allowing prediffusion from the tissues for 60 min. After 16 hours of incubation at + 30°C the diameter of the inhibition zones was registered with a vernier caliper and curves were plotted on semilogarithmic paper.