Study of the Impact on Physicochemical Properties of Inhaled Products in several Simulated Lung Fluid media

Purpose The aim of this poster was to study the impact of several simulated lung fluid (SLF) media on the physicochemical properties of a selected group of inhaled drugs. Physicochemical properties such as pKa, logP solubility and dissolution rates were measured at different conditions using protic and aprotic salts in phospholipid and surfactant systems to observe the impact of the media on the physicochemical properties of the drug. Sample properties were also compared with a standard phosphate buffer media. Methods Measurements were performed at, 37°C and 0.15M ionic strength using the SiriusT3 physchem profiling instrument. The SiriusT3 is an automated titration platform with in‐situ UV fibre‐optic spectroscopy. Small quantities of drug material were used in 1 to 3 mL volumes to determine pKa, logP, solubility and dissolution behaviour at pH=7.0. Media were prepared using sodium dodecyl sulphate (SDS) surfactant and a commercial phospholipid preparation (Curosurf ® , Takeda Pharma) with the addition of several protic and aprotic salts. Experiments were also carried out with phosphate buffer.