Release Of Flurbiprofen Research Articles

Rectal absorption of flurbiprofen, ketoprofen and indomethacin in polyacrylic acid aqueous gel preparation in rats

The bioavailability on rectal administration of flurbiprofen (FP), ketoprofen (KP) and indomethacin (Ind) with polyacrylic acid aqueous gel base was investigated in rats. When FP, KP and Ind were administered rectally with gel base at various pHs (5.0–8.0), their bioavailabilities increased upon higher pH. In the rectal administration of FP, KP and Ind with gel base at various concentrations (viscosities: 0.5–2.0 w/v%), higher bioavailabilities were obtained at lower concentrations (viscosity) of gel base. In the rectal administration of Ind with gel base containing oleic acid (10 v/v%), the bioavailability was higher and longer than that with simple gel base; however, that of FP and KP did not change without or with oleic acid. In the in vitro release experiments using micropore membrane, the effect of gel concentration (viscosity) was evident; the higher the viscosity of the gel preparation, the slower the FP, KP and Ind release. The results suggest that the release rate from the gel preparation is rate-limiting in the rectal absorption of FP, KP and Ind in gel preparations in rats. Thus, it can be assumed that polyacrylic acid aqueous gels are useful as a base for rectal administration of FP, KP and Ind.