Microscopy

Solid-state characterization of Felodipine–Soluplus amorphous solid dispersions

“…Although cubic crystals such as sodium chloride also have the same property as amorphous substances, they rarely exist in organic materials. Therefore, the crystalline and amorphous states of substances can be differentiated by polarized light owing to the different optical properties and the absence of birefringence is strong evidence of the existence of an amorphous state 58, 59 . As shown in Figure 6b, none of the SDs exhibited birefringence as contrasted to the crystalline FEL (Figure 6a), and the same observation was also made for the 10 and 50% SDs, which confirmed the amorphous state of FEL in the formulations.…”

“…SEM has been widely applied to characterize the solid-state properties of substances in the pharmaceutical industry owing to its high magnification and resolution 58 . The morphology of the selected samples was evaluated in SEM studies.…”