Pharmacokinetics of diclofenac sodium in normal man.

Diclofenac sodium was administered as 50 mg tablets to four healthy male volunteers in a two-way randomized crossover study in which volunteers were either fasted or were given a standard breakfast immediately prior to dosing. Blood samples were obtained upto 9 hours period and drug concentration were determined by HPLC method. Besides a significantly delayed (at p > 0.1) peak in fed state; an increase in absorption rate constant was observed as the only significant (at p > 0.05) effect of food on biopharmaceutic characteristic of diclofenac sodium. However, the intrinsic absorption of diclofenac sodium is also fast and it is not being the rate limiting factor in the bioavailability of diclofenac sodium, its decrease upto about 18 minutes (0.31 +/- 0.05 hr) from 11 minutes (0.19 +/- 0.02 hr) produces a null difference as the net effect on bioavailability, particularly when the drug is to be used in multiple dosage regimen.