The extent to which clindamycin is absorbed systemically following intravaginal application of clindamycin phosphate 1% cream was assessed in 12 healthy female volunteers. Each subject received a single intravenous dose of clindamycin phosphate sterile solution (48 mg). A week later, each subject received 50 mg (5 mL) doses of intravaginal cream according to one of two dosage regimens: once daily (qd) for seven consecutive doses or twice daily (q12hr) for 13 consecutive doses. Steady state was achieved on or before day 4 for both regimens. The absolute bioavailabilities of the two intravaginal treatments were 6% for qd dosing and 13% for q12hr dosing, indicating that only a small fraction of the intravaginal dose is absorbed systemically.