Recrystallization and Water Absorption Properties of Vitrified Trehalose Near Room Temperature

• Published in: Pharmaceutical research Vol. 35; no. 7; pp. 139 - 17
• Main Authors: Shirakashi, Ryo, Takano, Kiyoshi
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.07.2018; Springer; Springer Nature B.V
• Subjects: Absorption; Absorptivity; Affinity; Analysis; Aqueous solutions; Biochemistry; Biomedical and Life Sciences; Biomedical Engineering and Bioengineering; Biomedicine; Crystallization - methods; Fourier transforms; Hot Temperature; Humidity; Hypotheses; Medical Law; Pharmacology/Toxicology; Pharmacy; Phase transitions; Physicochemical properties; Recrystallization; Research Paper; Spectrum analysis; Surface energy; Surface properties; Temperature effects; Thin films; Trehalose; Trehalose - chemistry; Trehalose - metabolism; Trehalose dihydrate; Vacuum; Viscosity; Vitrification; Water - chemistry; Water - metabolism; Water absorption; Water activity; Water vapor; X-Ray Diffraction - methods; trehalose; amorphous; recrystallization; vacuum-drying; water absorption
• ISSN: 0724-8741; 1573-904X
• DOI: 10.1007/s11095-018-2420-7

Purpose To provide the physicochemical properties of vitrified trehalose for predicting its recrystallization. Methods Thin films of vitrified trehalose solutions were prepared at room temperature and exposed to various humid and temperature atmospheres. The in-situ amount of retained water in the vacuum-dried trehalose thin film during exposure was determined using its FTIR spectrum by quantifying the extremely infinitesimal amount of retained water in the trehalose solution. Recrystallization of the sample was also assessed by the FTIR spectrum of trehalose dihydrate. Results The effective water absorption coefficient, h meff , exponentially increased to the water activity of the trehalose sample, A w , at 25°C and 40°C at which the increasing rates are comparable. The surface energy of trehalose dihydrate, γ , was found to be lower than the value calculated from the reported equation, neglecting the effects of the activity of the solute and solvent water. Conclusions The retained water in trehalose considerably increases its affinity for water vapor, and the change in this affinity with regard to the water activity is nearly independent of temperature. The dihydrate nucleation rate of trehalose-water system is maximal when trehalose weight ratio is ~0.8 at 25°C and is slightly higher (~0.85) at 40°C.