Recrystallization of waxy maize starch during manufacturing of starch microspheres for drug delivery: Influence of excipients
| Autor: | Marie Wahlgren, Anna Simpraga, Ann-Charlotte Eliasson, Lidia Elfstrand, Bernt Thelin, Malin Larsson, Monica Jönsson |
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| Rok vydání: | 2007 |
| Předmět: |
Chromatography
Polymers and Plastics Chemistry Starch Organic Chemistry Excipient Polyethylene glycol Maize starch law.invention chemistry.chemical_compound Differential scanning calorimetry Chemical engineering law Materials Chemistry medicine Thermal stability Crystallization Sodium carbonate medicine.drug |
| Zdroj: | Carbohydrate Polymers. 69:732-741 |
| ISSN: | 0144-8617 |
| Popis: | The formation of ordered structure, such as crystallites, in starch was studied by means of differential scanning calorimetry (DSC). The influence of time/temperature treatment and additives such as polyethylene glycol (PEG), bovine serum albumin (BSA) and a carbonate buffer on the formation was investigated. The experiments were planned with a CCC (Central Composite Circumscribed) design. For all three investigated systems it could be concluded that the incubation time at 6 °C was the decisive factor for the amount of ordered structure obtained during the incubation, while the incubation time at 37 °C was the decisive factor for the thermal stability of the crystallites as expressed by Ton, Tm and Tc. The additives seemed to mainly affect the nucleation phase of crystallization process. The additives decreased the time required in order to obtain a certain level of ordering in the incubated starch samples. The carbonate buffer decreased the amount of ordered structure in starch as judged by DSC enthalpy values, while increasing the melting temperature of these structures. The additives PEG and BSA lowered the melting temperatures of the starch in the systems but increased the enthalpy values. By optimization procedure a specific amount of ordered structure with desired thermal characteristics could be predicted. |
| Databáze: | OpenAIRE |
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