Absorption kinetics of topical clindamycin preparations

Systemic clindamycin absorption was examined in 12 male Caucasians without acne who recieved 1 ml of Cleocin-T® and 1 ml of 1 per cent clindamycin HCl in Vehicle-N® (Neutrogena) applied topically the face every 12 h for 4 days according to a crossover design. In a separate phase clindamycin phosphate was administered by an IV infusion of 300 mg over 10 min. Systemic absorption was much higher with clindamycin in Vehicle-N than with Cleocin-T. Absolute bioavailability calculated from cumulative urinary excretion and serum AUCs were in good agreement and averaged 1·7 per cent and 7·5 per cent for Cleocin-T and clindamycin in Vehicle-N, respectively. Peak serum concentrations ranged from less than 0·5 ng ml⁻¹ to 6 ng ml⁻¹ for Cleocin-T and from 4–20 ng ml⁻¹ for clindamycin in Vehicle-N. Absorption profiles indicated zero order absorption with Cleocin-T. No appreciable systemic accumulation from the repeated topical applications was noted. Systemic exposure to clindamycin from these formulations is minimal.