Particle Size and Density in Spray Drying—Effects of Carbohydrate Properties

Characterization of the molecular distribution of drugs in glassy solid dispersions at the nano-meter scale, using differential scanning calorimetry and gravimetric water vapour sorption techniques

In this paper we analyse the phase and state transitions of starch and other glucose homopolymers and oligomers using the free volume extension of the Flory–Huggins theory by Vrentas and Vrentas, combined with the Couchman–Karasz theory for the glass transition. Using scaling relations of model parameters with molar weight we have obtained accurate predictions of moisture sorption and the freezing, boiling, and melting data obtained from literature for starch, dextrans, pullulan and maltodextrins. With the estimated model parameters we can construct the complete state diagram for starch, which can now be used as a quantitative tool for design and analysis of food structuring processes.

Prediction of the state diagram of starch water mixtures using the Flory–Huggins free volume theory

Effects of Types of Sugar on the Stabilization of Protein in the Dried State

The AB2- and AB3-type miktoarm star copolymers consisting of maltoheptaose (MH, as A block) and poly(e-caprolactone) (PCL, as B block), namely MH-b-(PCL)2 and MH-b-(PCL)3, were synthesized, and their nano-organization was characterized. The syntheses of MH-b-(PCL)2 and MH-b-(PCL)3 were carried out through two reaction steps: (1) preparation of linear and three-branched PCLs bearing an azido group on the chain center (N3-(PCL)2 and N3-(PCL)3) by the diphenyl phosphate-catalyzed ring-opening polymerization of e-caprolactone (e-CL) using azido-functionalized di- and triols (N3-(OH)2 and N3-(OH)3) as the initiators and (2) the copper-catalyzed azide–alkyne cycloaddition of N3-(PCL)2 and N3-(PCL)3 with the ethynyl-functionalized MH. The miktoarm star copolymers having Mn for the PCL block of ca. 5000 (MH-b-(PCL2.5k)2 and MH-b-(PCL1.7k)3) and 10 000 (MH-b-(PCL5k)2 and MH-b-(PCL3.3k)3) were obtained with a very narrow polydispersity index of less than 1.05. Bulk samples of the four types of miktoarm star copolym...

Sub-10 nm Nano-Organization in AB2- and AB3-Type Miktoarm Star Copolymers Consisting of Maltoheptaose and Polycaprolactone

Temperature scanning Fourier transform infrared, TS-FTIR, spectroscopy of various amorphous sugar matrixes was conducted to investigate the relationship between the glass transition temperature, T(g), of an amorphous sugar matrix and the nature of the hydrogen bonds in the matrix. An amorphous sugar matrix was prepared by air-drying an aqueous solution of sugar, and the degree of formation of hydrogen bonds in the matrix was evaluated at different temperatures using the peak positions of the IR band corresponding to the O-H stretching vibration at around 3400 cm(-1). The T(g) value increased with increasing peak position of the O-H stretching vibration at T(g) and were correlated reasonably well with the magnitude of the peak shift by the temperature increase (from 25 degrees C) to the T(g) value. This demonstrates that the amorphous sugar matrix, in which the segments are fixed by fewer hydrogen bonds, has a higher thermal resistance. The glycosidic linkage largely contributes to the restriction of the segments, pyranose ring, rather than a hydrogen bond. As the degree of polymerization of pyranose rings increases, the degree of hydrogen bond formation needed to hold the matrix in a fixed position decreases. However, the magnitude of the restriction of pyranose rings by a glycosidic linkage changes depending on the type: the restrictions imposed by alpha-1,1 and -1,6 glycosidic linkages are the tightest and most flexible of all of the types of glycosidic linkages, respectively.

Temperature scanning FTIR analysis of hydrogen bonding states of various saccharides in amorphous matrixes below and above their glass transition temperatures.

Water sorption and glass transition behaviors of freeze‐dried sucrose–dextran mixtures

Water sorption, glass transition, and protein‐stabilizing behavior of an amorphous sucrose matrix combined with various materials

The effects of various additives on the physical properties of an amorphous sugar matrix were compared. Amorphous, sugar-additive mixtures were prepared by freeze-drying and then rehumidified at given RHs. Sucrose and eighteen types of substances were used as the sugar and the additive, respectively, and water sorption, glass-to-rubber transition, and protein stabilization during freeze-drying for the various sucrose-additive mixtures were examined. The additives were categorized into two groups according to their effects on Tg and water sorption. Presence of polysaccharides, cyclodextrins, and polymers (large-sized additives) resulted in a decrease in equilibrium water content from the ideal value calculated from individual water contents for sucrose and additive, and in contrast, low MW substances containing ionizable groups (small-ionized additives) resulted in an increase. The increase in Tg by the addition of large-sized additives was significant at the additive contents >50 wt.% whereas the Tg was markedly increased in the lower additive content by the addition of small- ionized additives. The addition of small-ionized additives enhanced the decrease in Tg with increasing water content. The protein stabilizing effect was decreased with increasing additive content in the cases of the both groups of the additives. 2010 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99:4669-4677, 2010

PHARMACEUTICAL TECHNOLOGY Water Sorption, Glass Transition, and Protein-Stabilizing Behavior of an Amorphous Sucrose Matrix Combined With Various Materials

Atsushi Fukushima

Papers

Temperature scanning FTIR analysis of hydrogen bonding states of various saccharides in amorphous matrixes below and above their glass transition temperatures.

Water sorption and glass transition behaviors of freeze‐dried sucrose–dextran mixtures

Water sorption, glass transition, and protein‐stabilizing behavior of an amorphous sucrose matrix combined with various materials

PHARMACEUTICAL TECHNOLOGY Water Sorption, Glass Transition, and Protein-Stabilizing Behavior of an Amorphous Sucrose Matrix Combined With Various Materials