Cary 660

Mid-IR FTIR analysis was conducted in the spectral range of 4000–650 cm⁻¹ using Cary 660 and Cary 620 FTIR Microscopes (Agilent Technologies, Santa Clara, CA, USA). The bench was equipped with a MIRacle ATR (Pike Technologies, Fitchburg, WI, USA), that was fitted with a single-bounce, diamond-coated ZnSe internal reflection element. Chemical imaging was conducted using Cary 620 FTIR Microscope (Agilent Technologies, Santa Clara, CA, USA) equipped with a 64 × 64 pixel focal plane array (FPA) with and without a germanium micro-ATR. FTIR samples were studied before and after physical blending and melt extrusion to study intermolecular interactions before and after applying high shear forces and elevated temperatures. The chemical imaging samples were embedded in melted paraffin (Paraplast X-TRA^®, Sigma-Aldrich, St. Louis, MO, USA) and reduced to 5-μm thickness using a microtome (Olympus America Inc., Center Valley, PA, USA) to allow IR light to penetrate it and reflect out. Chemical imaging was utilized to visually approximate drug homogeneity and interactions.

FT-IR analysis was conducted in the spectral range of 4000–650 cm⁻¹ using a Cary 660 instrument (Agilent Technologies, Santa Clara, CA, USA). The bench was equipped with a MIRacle ATR accessory (Pike Technologies, Fitchburg, WI, USA) that was fitted with a single bounce, diamond-coated ZnSe internal reflection element. FT-IR was performed to determine the molecular interactions of pure TEL alone and in the presence of SC, MEG, NEU and HPMCAS LG in the formulations before and after applying high shear forces and elevated temperatures.