Bioavailability of diclofenac sodium with vaginal administration in healthy women

Plasma concentration of diclofenac were studied in four healthy women after oral, vaginal, and rectal administration of 100 mg. The area under the concentration time curve (AUC) for diclofenac administration by vaginal route was significantly greater than the AUC after oral administration (4.2 μg·hr/ml and 2.1 μg·hr/ml, respectively), achieving complete bioavailability versus rectal administration. The time to maximal drug plasma concentration (six hours) was also quite different by vaginal route compared with oral (1 to 1.5 hours) or rectal (0.5 to 1 hour) absorption. The obtained results suggest this form of treatment is a valid alternative as far as safety and tolerance are concerned, especially in long-term treatment.