Enhancement of systemic and CNS delivery of meptazinol hydrochloride by intranasal administration to rats.

To investigate the extent of systemic absorption and uptake of meptazinol (MEP) hydrochloride in cerebrospinal fluid (CSF) after intranasal administration on rats and compare with oral administration. CSF samples were collected by a serial sampling method. The concentration of MEP in the biological samples was measured by HPLC with fluorescence detector. Rapid and significant levels of MEP in plasma and CSF can be achieved after nasal administration whereas the oral administration resulted in considerably lower drug concentrations. AUC in plasma and CSF from the nasal route are 7.375 and 15.6 folds compared with those of the oral route, respectively. Intranasal MEP is able to show quick absorption and improve the bioavailability, which could be a promising alternative to oral administration.