Background and aims Intra-tracheal instillation of budesonide (B) using surfactant (S) as a vehicle significantly improved pulmonary status. The stability of the S/B mixture has not been studied. The aim of study is to investigate if S can be used as an vehicle to facilitate B delivery in rats and if the S/B mixture is biophysically and chemically stable.
Methods and materials A Nano/PET digital scan was performed on rat that was intratracheally injected with S/18-F labelled B mixture, with 18-F-B only, or with free 18-F. The 18-F radioactivity was measured at 30 min. after injection. To test biophysical property, the dynamic surface tension behaviour of S/B suspension was conducted in Surfactometer. HPLC was performed with various S/B concentration ratios within 24 hrs after S/B mixing.
Results 1) 18-F-B radioactivity was detected more in the peripheral lung in rat supplemented with S than in rat without S. 2) using a concentration of S/B ≥ 50:1, the dynamic surface activity of S was minimally affected 3) HPLC analysis revealed no new compound detected within 24 h after mixing of S/B
Conclusions S can be used as an effective vehicle and that, with a S/B ratio of ≥ 50, the mixture is biophysically and chemical stable.