Tissue Distribution of [C]-Lefamulin into the Urogenital Tract in Rats.

Lefamulin, a semisynthetic pleuromutilin antibiotic approved in the United States, Canada, and Europe for intravenous and oral treatment of community-acquired bacterial pneumonia, is highly active against bacterial pathogens that cause sexually transmitted infections (STIs), including multidrug-resistant strains of Neisseria gonorrhoeae, Chlamydia trachomatis, and Mycoplasma genitalium. This nonclinical study used quantitative whole-body autoradiography (QWBA) and qualitative tape-transfer microautoradiography (MARG) to investigate lefamulin distribution into urogenital tract tissues down to a cellular level in male and female rats. A single intravenous dose (30 mg/kg) of [C]-lefamulin was administered to 3 male and 3 female Sprague-Dawley rats.

An OECD TG 428 study ring trial with C-Caffeine demonstrating repeatability and robustness of the dermal absorption in vitro method.

The dermal absorption potential of C-Caffeine applied as a 4 mg/mL concentration (10 μL/cm finite dose) was investigated in six laboratories under Good Laboratory Practice conditions using an OECD TG 428-compliant in vitro assay with flow-through cells and split-thickness human skin. Potential sources of variation were reduced by a standardized protocol, test item and skin source. Particularly, skin samples from same donors were distributed over two repeats and between labs in a non-random, stratified design.