Drug Release and Pharmacokinetic Evaluation of Novel Implantable Mometasone Furoate Matrices in Rabbit Maxillary Sinuses.

Background: Intranasal corticosteroid sprays (INCSs) used to treat chronic rhinosinusitis are suboptimal due to limited penetration into the middle meatus, rapid clearance, and poor patient compliance. A bioresorbable drug matrix, developed with the XTreo drug delivery platform, may overcome the limitations of INCS by providing continuous dosing over several months.

Objective: To evaluate the in vitro drug release and in vivo pharmacokinetics of novel mometasone furoate (MF) matrices in a rabbit dorsal maxillary osteotomy model.

Methods: XTreo matrices were formulated to consistently elute MF for up to 6 months. Matrices were surgically placed bilaterally into the maxillary sinuses of New Zealand White (NZW) rabbits. Tissue and plasma MF concentrations were measured to assess the in vivo drug delivery. The in vivo and in vitro drug release kinetics of the matrices were quantified and compared to those of rabbits receiving daily Nasonex MF nasal sprays.

Results: XTreo matrices self-expanded upon deployment to conform to the irregular geometry of the maxillary sinus cavities in the NZW rabbits. Sustained release of MF was demonstrated in vitro and in vivo for 2 MF matrices of distinct release durations and an in vitro-in vivo correlation was established. Therapeutic levels of MF in local tissues were measured throughout the intended dosing durations. In contrast to the variable peaks and troughs of daily nasal sprays, sustained dosing a single administration of MF matrices was confirmed by quantifiable plasma MF concentrations over the intended dosing duration.

Conclusion: The XTreo MF matrices provided targeted and efficient dosing to local sinus tissues that was superior to INCS. Sustained drug release was confirmed both in vitro and in vivo. The novel XTreo technology may provide precisely tuned, long-lasting drug delivery to sinus tissues with a single treatment.