The pharmacokinetics of a new sustained-release form of diclofenac sodium in humans.

In the present study, two sustained release diclofenac preparations were administered every 12 hours over 4 days to ten human volunteers. Diurnal profiles were recorded on the 1st and 4th days, from which pharmacokinetic parameters were calculated: particular attention was given to cumulation. One, a newly developed sustained release formulation, had a MRT of 5.5 hours, and showed surprisingly small variation coefficients [AUC ss (72-84 hrs) +/- 26%; Cmax ss (72-84 hrs) +/- 19%] after 7 administered doses; accordingly, the maximum concentrations were within a very narrow time window [tmax ss (72-84 hrs) range: 1.5-2.5 hours after administration]. Due to the selected release profiles with this formulation, there was no danger of cumulation in spite of administration every 12 hours [AUC 0-12 hrs, mean value = 1555 ng/ml x h; AUC ss 72-84 hrs, mean value = 1750 ng/ml x h].