Pharmacokinetic analysis of the absorption characteristics of diclofenac sodium in man by use of a multi-segment absorption model.
The pharmacokinetic analysis of an oral sustained-release preparation of diclofenac sodium has been investigated using multi-segment absorption models in which it has been assumed that the gastrointestinal tract can be divided into several segments in each of which the drug has its own lag-time and absorption rate constants. Plasma concentration-time data for sustained release diclofenac sodium in man were fitted both by a conventional pharmacokinetic method assuming first-order absorption and by a multi-segment absorption model. The plasma concentration of diclofenac sodium calculated on the basis of the multi-segment absorption model was found to correlate with the observed plasma concentration. It was concluded that diclofenac sodium data can be better described by a multi-segment absorption model than by a conventional pharmacokinetic model. The results also show that multi-segment absorption models are suitable for pharmacokinetic analysis of plasma drug-concentration data with irregular or multiple peaks in the absorption profiles, and also for the pharmacokinetic analysis of sustained-release preparations.
Mahmood
I
I
Office of Clinical Pharmacology and Biopharmaceutics, Food & Drug Administration, Rockville, MD 20852, USA.
D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000493:pharmacokinetics*; D004008:Diclofenac / Q000493:pharmacokinetics*; D006801:Humans; D007408:Intestinal Absorption; D008954:Models, Biological
D000894:Anti-Inflammatory Agents, Non-Steroidal; D004008:Diclofenac