Trials of in situ-gelling and mucoadhesive acetaminophen liquid suppository in human subjects

Abstract For the development of in-situ gelling and mucoadhesive acetaminophen liquid suppository prepared with poloxamers (P 407, P 188) and sodium alginate, the physicochemical characteristics of liquid suppositories [acetaminophen/P 407/P 188/sodium alginate (5/15/19/0–1.0%)] were evaluated. Furthermore, a pharmacokinetic study of acetaminophen from liquid and conventional solid suppositories in human subjects was carried out. The results showed that acetaminophen liquid suppository [acetaminophen/P 407/P 188/sodium alginate (5/15/19/0.6%)] with optimal gelation temperature, gel strength and bioadhesive force had a similar release pattern to conventional suppository. The area under the drug concentration–time curve (AUC), mean residence time (MRT), biological half-life ( t 1/2 ) and apparent elimination rate constant ( K el ) of acetaminophen from liquid suppository were not significantly different from those from conventional suppository. However, liquid suppository gave significantly faster the time to reach the maximum plasma concentration ( T max ) and higher the maximum plasma concentration of drug ( C max ) of acetaminophen than conventional suppository ( p