Kinetics of rate controlled rectally administered ranitidine to male volunteers
Ranitidine hydrochloride solution was given rectally to six healthy volunteers by means of an osmotic pump (Osmet®) at a zero-order rate for 8 h. Quite constant steady-state drug concentrations were achieved in the range of 64–123 ng/ml plasma (meanCss: 100.6 ng/ml). The mean absorption time was 0.45 h (range 0–1.02 h), indicating that absorption was not always instantaneous. It is concluded that the Osmet® system together with the rectal route offer the possibility for achieving steady-state concentrations of ranitidine, enabling the determination of pharmacodynamic effects. In addition, the rectal route can be considered as an alternative to oral and intravenous administration.
Key wordsAdministration, rectal Osmotic pump Pharmacokinetics Ranitidine
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