Biodistribution and kinetics of nasal carbon-11-triamcinolone acetonide.
PET is a technique with a strong potential for use in drug evaluation and development. In particular, the distribution and pharmacokinetics of locally administered drugs may be advantageously explored noninvasively using labeled compounds. This pilot study was performed to demonstrate the effectiveness of PET for drug development and to determine the human biodistribution and kinetics of triamcinolone acetonide, labeled with 11C, formulated and nasally administered as Nasacort AQ nasal inhalant.


METHODS
Carbon-11-labeled triamcinolone acetonide was formulated as the commercial product, and PET scans of the heads of four volunteers were performed in a vertical orientation. Region-of-interest analysis with MRI coregistration was used to analyze the distribution and kinetics in nasal tissues.


RESULTS
Deposition of the majority of the dose on target tissues was immediate. Penetration into sinuses was observed. There was moderate redistribution and slow migration of the drug through nasal passages to the throat. Significant amounts of the drug remained in target regions for several hours.


CONCLUSIONS
PET is an effective means to determine local drug distribution and kinetics.
Berridge
M S
MS
Case Western Reserve University/University Hospitals of Cleveland, Division of Radiology, Ohio 44106, USA.
Heald
D L
DL
Muswick
G J
GJ
Leisure
G P
GP
Voelker
K W
KW
Miraldi
F
F
D000280:Administration, Inhalation; D000328:Adult; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D002250:Carbon Radioisotopes; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D009297:Nasal Mucosa / Q000378:metabolism; D014018:Tissue Distribution; D014055:Tomography, Emission-Computed; D014222:Triamcinolone Acetonide / Q000008:administration & dosage / Q000493:pharmacokinetics*
D000893:Anti-Inflammatory Agents; D002250:Carbon Radioisotopes; D014222:Triamcinolone Acetonide