Feasibility of the Ph.Eur. flow-through cell for dissolution testing of the compounded rectal suppositories containing indomethacin or sodium diclofenac.

Ph.Eur. and BP have introduced a dissolution apparatus for suppositories. Suitability of the apparatus for quality control of indomethacin or sodium diclofenac (100 mg) compounded suppositories was evaluated and the effect of the type of suppository base on dissolution profiles was studied. The fastest and most reproducible release profiles were observed for hydrophilic base (macrogols). More than 80% of the drug was released during 60 min, while after 350 min 18.5-50% of the total amount was released from lipophilic bases (Witepsol and Adeps solidus). The results demonstrate that slow and non-reproducible release occurs when the lipophilic suppository base does not melt. The feasibility of the test for the formulations, which do not melt during the procedure, is questionable.