Phase transitions of ascorbic acid and sodium ascorbate in a polymer matrix and effects on vitamin degradation

Ismail, Yahya A.; Mauer, Lisa J.

doi:10.1111/jfpe.13073

Cited by 9 publications

(9 citation statements)

References 46 publications

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“…The intermolecular interactions between thiamine and polymers in the solid dispersions were therefore also proposed as the explanation for the greater chemical stability of TClHCl:PEC amorphous solid dispersions compared to TClHCl:PVP dispersions, wherein PEC protected thiamine against chemical degradation by restricting the molecular mobility of TClHCl (higher molecular mobility resulted in an increased degradation rate). A similar observation was also reported by Ismail and Mauer [29], who found that stronger intermolecular interactions between PVP and ascorbic acid than between PVP and sodium ascorbate were likely a contributing factor for the higher stability of ascorbic acid in these PVP-based amorphous solid dispersions. Due to lack of interactions between TClHCl and PVP in the amorphous solid dispersions in this study, thiamine was significantly less stable in PVP dispersions than in PEC dispersions that had more vitamin-polymer intermolecular interactions.…”

Section: Effect Of Polymer Type On Thiamine Degradation In Amorphous Solid Dispersionssupporting

confidence: 88%

Amorphization of Thiamine Chloride Hydrochloride: Effects of Physical State and Polymer Type on the Chemical Stability of Thiamine in Solid Dispersions

Arıoğlu-Tuncil

Voelker

Taylor

et al. 2020

IJMS

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Thiamine is an essential micronutrient, but delivery of the vitamin in supplements or foods is challenging because it is unstable under heat, alkaline pH, and processing/storage conditions. Although distributed as a crystalline ingredient, thiamine chloride hydrochloride (TClHCl) likely exists in the amorphous state, specifically in supplements. Amorphous solids are generally less chemically stable than their crystalline counterparts, which is an unexplored area related to thiamine delivery. The objective of this study was to document thiamine degradation in the amorphous state. TClHCl:polymer dispersions were prepared by lyophilizing solutions containing TClHCl and amorphous polymers (pectin and PVP (poly[vinylpyrrolidone])). Samples were stored in controlled temperature (30–60 °C) and relative humidity (11%) environments for 8 weeks and monitored periodically by X-ray diffraction (to document physical state) and HPLC (to quantify degradation). Moisture sorption, glass transition temperature (Tg), intermolecular interactions, and pH were also determined. Thiamine was more labile in the amorphous state than the crystalline state and when present in lower proportions in amorphous polymer dispersions, despite increasing Tg values. Thiamine was more stable in pectin dispersions than PVP dispersions, attributed to differences in presence and extent of intermolecular interactions between TClHCl and pectin. The results of this study can be used to control thiamine degradation in food products and supplements to improve thiamine delivery and decrease rate of deficiency.

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Section: Effect Of Polymer Type On Thiamine Degradation In Amorphous Solid Dispersionssupporting

confidence: 88%

Amorphization of Thiamine Chloride Hydrochloride: Effects of Physical State and Polymer Type on the Chemical Stability of Thiamine in Solid Dispersions

Arıoğlu-Tuncil

Voelker

Taylor

et al. 2020

IJMS

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“…However, even in the samples stored at 11% RH, where water content was much lower and not a differentiating factor, amorphous TMN was more chemically stable in the presence of PEC than PVP. This was presumably due to stronger/more extensive intermolecular interactions between TMN and PEC than between TMN and PVP ( Figure 3 ), consistent with previous studies on the effect of intermolecular interactions on chemical stability of components within amorphous solid dispersions [ 10 , 17 ]. In general, thiamine was less chemically stable in the amorphous state than in the crystalline state, and the chemical stability of thiamine in amorphous solid dispersions was dependent on polymer type due to both intermolecular interactions with the polymer and the variable hygroscopicity of the systems in the different storage environments.…”

Section: Resultssupporting

confidence: 90%

Amorphization of Thiamine Mononitrate: A Study of Crystallization Inhibition and Chemical Stability of Thiamine in Thiamine Mononitrate Amorphous Solid Dispersions

Arıoğlu-Tuncil

Voelker

Taylor

et al. 2020

IJMS

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This study investigated thiamine degradation in thiamine mononitrate (TMN):polymer solid dispersions, accounting for the physical state of the vitamin and the recrystallization tendency of TMN in these dispersions. Results were compared with those from solid dispersions containing a different salt form of thiamine (thiamine chloride hydrochloride (TClHCl)). TMN:polymer dispersions were prepared by lyophilizing solutions containing TMN and amorphous polymers (pectin and PVP (polyvinylpyrrolidone)). Samples were stored in controlled temperature and relative humidity (RH) environments for eight weeks and monitored periodically by X-ray diffraction and high performance liquid chromatography (HPLC). Moisture sorption, glass transition temperature (Tg), intermolecular interactions, and pH were also determined. Similar to the TClHCl:polymer dispersions, thiamine was more chemically labile in the amorphous state than the crystalline state, when present in lower proportions in amorphous TMN:polymer dispersions despite increasing Tg values, when environmental storage conditions exceeded the Tg of the dispersion, and when co-formulated with PVP compared to pectin. When thiamine remained as an amorphous solid, chemical stability of thiamine did not differ as a function of counterion present (TMN vs. TClHCl). However, storage at 75% RH led to hydration of thiamine:PVP dispersions, and the resulting pH of the solutions as a function of thiamine salt form led to a higher chemical stability in the acidic TClHCl samples than in the neutral TMN samples.

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“…An identical T g is observed for each sample, representing the PCL matrix. Based on the Boyer–Beaman rule, the T g value of AA is estimated to be 35.6 °C . Sanchez et al determined the T g of pure AA to be around 40.1 °C using the melt quenching method .…”

Section: Resultsmentioning

confidence: 99%

“…Glass-transition temperatures (T g ) were determined using the temperature of half the step height in the specific heat curve. Isothermal scans were recorded at 38,39,40,41,42,43, and 44 °C. Samples were held at 90 °C for 5 min before quickly cooling (100 °C/min) to the selected crystallization temperature.…”

Section: Methodsmentioning

confidence: 99%

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Miscibility, Morphology, and Crystallization Kinetics of Biodegradable Poly(ε-caprolactone)/Ascorbic Acid Blends

Eesaee

Müller

O’Reilly

et al. 2021

ACS Appl. Polym. Mater.

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Poly(ε-caprolactone) (PCL) was blended with l-ascorbic acid (AA) to achieve increased hydrophilicity and shorter degradation period as a candidate for specific biomedical applications such as bio tissue engineering scaffolds. The miscibility, morphology, and spherulite development of PCL/AA blends were investigated via several means of microscopy. Microscopic observations demonstrated that the PCL and AA form immiscible blends. At 1 and 2 wt % AA in the PCL matrix, AA was distributed in the form of small particles. For the sample with 5 wt % of AA, micrometric crystal aggregates of AA were also seen, randomly distributed. The presence of AA impacted the spherulite development of PCL upon crystallization from melt and solvent evaporation. At low percentages of AA (1 and 2 wt %), while not interacting with the lamellar growth, AA caused a minor nucleating effect on PCL, resulting in a smaller average spherulitic size. On the other hand, 5% of AA left behind micrometric crystals and the PCL spherulites tend to grow from the surface of AA microcrystals. The natural evaporation of solvent resulted in aggregates of AA; however, when given time and at elevated temperatures, AA crystals were nucleated and grown in the form of needle-like crystals at random directions. The overall isothermal crystallization of PCL/AA blends was determined by DSC. Even though AA has a small nucleating effect on PCL, the overall crystallization rate decreased with AA addition. We attribute the decrease to a reduction in spherulitic growth rate due to a possible interaction between AA and PCL, resulting in a limited diffusion and reduced mobility of PCL chains. In addition, short-term hydrolytic degradation resulted in the removal of AA particles from the surface of PCL/AA blends. As a result, a porous structure of PCL remained, which was hypothesized to have a higher rate of surface degradation.

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Phase transitions of ascorbic acid and sodium ascorbate in a polymer matrix and effects on vitamin degradation

Cited by 9 publications

References 46 publications

Amorphization of Thiamine Chloride Hydrochloride: Effects of Physical State and Polymer Type on the Chemical Stability of Thiamine in Solid Dispersions

Amorphization of Thiamine Chloride Hydrochloride: Effects of Physical State and Polymer Type on the Chemical Stability of Thiamine in Solid Dispersions

Amorphization of Thiamine Mononitrate: A Study of Crystallization Inhibition and Chemical Stability of Thiamine in Thiamine Mononitrate Amorphous Solid Dispersions

Miscibility, Morphology, and Crystallization Kinetics of Biodegradable Poly(ε-caprolactone)/Ascorbic Acid Blends

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