Molecular states of prednisolone dispersed in folded sheet mesoporous silica (FSM-16).
Modes of molecular interaction between prednisolone and mesoporous materials have been investigated by the technique of solid-state NMR. Folded sheet mesoporous material (FSM-16) was used as host material and prednisolone was used as guest molecule. A suspension of FSM-16 in prednisolone dichloromethane solution was evaporated to prepare the evaporated samples. (13)C NMR spectroscopy was used as well as powder X-ray diffractometry and differential scanning calorimetry. Crystalline behavior of prednisolone disappeared in the evaporated samples, indicating the monomolecular dispersion of prednisolone in FSM-16 matrices. NMR peak shifts and broadening could be attributed to the molecular interaction between the A ring of prednisolone and FSM-16. Thermal properties of prednisolone were investigated after heat treatment of the evaporated samples. The results indicated that the thermal stability of the dispersion made from FSM-16 of large pore size was superior to that from FSM-16 of small pore size. Hydrocortisone was used to compare the dispersion state with prednisolone. It was suggested that the double bond at the C-1 and C-2 positions of prednisolone might play an important role in the process of adsorption of prednisolone to FSM-16.
Nishiwaki
Akinori
A
Graduate School of Pharmaceutical Sciences, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan.
Watanabe
Aya
A
Higashi
Kenjirou
K
Tozuka
Yuichi
Y
Moribe
Kunikazu
K
Yamamoto
Keiji
K
D000327:Adsorption; D002152:Calorimetry, Differential Scanning; D003460:Crystallization; D004355:Drug Stability; D005079:Excipients / Q000737:chemistry*; D005938:Glucocorticoids / Q000737:chemistry*; D006358:Hot Temperature; D006854:Hydrocortisone / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008752:Methylene Chloride / Q000737:chemistry; D016062:Porosity; D011239:Prednisolone / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D014961:X-Ray Diffraction
D005079:Excipients; C481639:FSM 16; D005938:Glucocorticoids; D008752:Methylene Chloride; D012822:Silicon Dioxide; D011239:Prednisolone; D006854:Hydrocortisone