Pharmacokinetic comparisons of three nasal fentanyl formulations; pectin, chitosan and chitosan-poloxamer 188.

OBJECTIVES

To optimize the absorption profile and reduce C(max), three new fentanyl nasal spray formulations have been developed: fentanyl pectin (FPNS), fentanyl chitosan (FChNS) and fentanyl in chitosan-poloxamer 188 (FChPNS). The venous pharmacokinetic profiles and tolerability of these formulations were assessed and compared with oral transmucosal fentanyl citrate (OTFC) lozenge.

SUBJECTS AND METHODS

This randomized, open-label, crossover study was conducted in opioid-naïve, healthy adult volunteers. Subjects were dosed under naltrexone blockade on four occasions with three nasal sprays (100 microg in 100 microl) and OTFC 200 microg. Fentanyl venous plasma concentrations were measured up to 24 h post-dose. Tolerability was assessed by clinical nasal assessments and a nasal reactogenicity questionnaire.

RESULTS

18 subjects were enrolled and completed the study. The mean dose-normalized AUC(0-infinity) for each nasal formulation was significantly higher (p < 0.05) compared with OTFC. Bioavailability compared with OTFC was significantly greater for all nasal fentanyl formulations (FPNS 132.4%, FChNS 154.1%, FChPNS 122.3%). Median tmax (FPNS 0.33 h, FChNS 0.17 h, FChPNS 0.26 h) were significantly (p < 0.001) reduced (OTFC 1.5 h) and mean C(max) significantly increased with all nasal formulations compared with OTFC. Nasal reactogenicity symptom incidence was lowest for the FPNS formulation (FPNS 2, FChNS 28 and FChPNS 45).

CONCLUSIONS

All nasal formulations demonstrated significantly increased systemic exposure and reduced times to peak plasma values compared with OTFC. The FPNS formulation exhibited the most favorable nasal and general tolerability profiles. It appears suitable for further investigation in breakthrough cancer pain management.