Evaporation of fentanyl from ceramics for pulmonary drug delivery: a pilot study

Abstract

Fast and non-invasive pain relief has been one of the primary goals in patient care. One suggested solution is to target the lungs, which allows the drug to be absorbed on a large surface area resulting in a very fast onset reaction. Ceramics possess great properties such as adjustable porosity and mild manufacturing conditions making them good candidates for drug delivery systems. Fentanyl is a very suitable component for treating acute and chronic pain due to its short duration of action. In this study, the possibility of using heat to evaporate fentanyl from ceramics for pulmonary drug delivery was evaluated. A slightly modified commercially available product (PAX 3) was used for the evaporation of fentanyl. Calcium sulfate was used as the drug carrier, i.e. by heating the fentanyl loaded calcium sulfate, fentanyl is released and can be inhaled. The ceramic loaded with fentanyl was heated to 230-250°C for 1-10 minutes and the vapor was collected in a syringe. The evaporated drug was collected and quantified with HPLC (High Pressure Liquid Chromatography). It was possible to evaporate up to 1.2 μg of the applied drug, while the remaining drug was left in the ceramic. Furthermore, unknown peaks were detected by the HPLC when the ceramics were exposed to higher temperatures and longer heating times. The results showed that it was possible to evaporate fentanyl from ceramics at temperatures below 250°C.