Salicylic Acid/γ-Cydodextrin 2:1 and 4:1 Complex Formation by Sealed-Heating Method

Large-ring Cyclodextrins

“…The recent study of an interaction of CD and drug in the solid state found a novel complex. Other drugs existed in the intermolecular space among the regularly threedimensional structures gathering columnar type structures that were assembled from CD alone or an inclusion complex between CD and drug (68)(69)(70). It suggests that CD10 and CD14 can form not only inclusion complexes, but also noninclusion complexes in solid state, since they can form a similar structure with the continuous cavity in the crystal state as shown in Fig.…”

Structural Evaluation of Crystalline Ternary γ-Cyclodextrin Complex

“…We have already reported that each g-CD molecule could be inhabited by two SA molecules in the intermolecular spaces in the g-CD columns after the sealed-heating process. 15,16 The amount of SA molecules per g-CD corresponded to those previously reported. Furthermore, the diffraction pattern of the SA/(FBP/g-CD) ¼ 2/(1/1) SH showed the monoclinic columnar form.…”

“…Furthermore, the diffraction pattern of the SA/(FBP/g-CD) ¼ 2/(1/1) SH showed the monoclinic columnar form. [14][15][16] It was found that the transformation from the hexagonal to the monoclinic columnar form, which was associated with an increase in intermolecular spaces, occurred because of the incorporation of SA molecules into these spaces. These results suggested a structure of the ternary complex in which the SA molecules were inhabited in the intermolecular spaces, and FBP remained in the g-CD cavity.…”

“…15,16 Sealed heating of SA with g-CD induced the formation of a complex with SA/g-CD ¼ 4/1 in which two SA molecules were incorporated into the g-CD cavity and two other SA molecules inhabited the intermolecular spaces. 15 SA molecules could occupy the intermolecular spaces when polyethylene glycol (PEG) molecules were incorporated into the cavity.…”

“…15,16 Sealed heating of SA with g-CD induced the formation of a complex with SA/g-CD ¼ 4/1 in which two SA molecules were incorporated into the g-CD cavity and two other SA molecules inhabited the intermolecular spaces. 15 SA molecules could occupy the intermolecular spaces when polyethylene glycol (PEG) molecules were incorporated into the cavity. 16 A previous study showed that the sealed-heating technique induced the formation of a crystalline ternary g-CD complex containing two pharmaceutical drugs, naproxen (NPX) and flurbiprofen (FBP).…”