Microencapsulated Vitamin A Palmitate Degradation Mechanism Study To Improve the Product Stability

Solvent-Free Loading of Vitamin A Palmitate into β-Cyclodextrin Metal-Organic Frameworks for Stability Enhancement

Cyclodextrin metal-organic frameworks (CD-MOFs) exhibit a high structural diversity, which contributes to their functional properties. In this study, we have successfully synthesized a novel type of β-cyclodextrin metal-organic framework (β-CD-POF(I)) that exhibits excellent drug adsorption capacity and enhances stability. Single-crystal X-ray diffraction analysis revealed that β-CD-POF(I) possessed the dicyclodextrin channel moieties and long-parallel tubular cavities. Compared with the reported β-CD-MOFs, the β-CD-POF(I) has a more promising drug encapsulation capability. Here, the stability of vitamin A palmitate (VAP) was effectively improved by the solvent-free method. Molecular modeling and other characterization techniques like synchrotron radiation Fourier transform infrared spectroscopy (SR-FTIR), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), and nitrogen adsorption isotherm were applied to confirm that the VAP was successfully encapsulated into the channel formed by the dicyclodextrin pairs. Furthermore, the mechanism of stability enhancement for VAP was determined to be due to the constraint and separation effects of β-CD pairs on VAP. Therefore, β-CD-POF(I) is capable of trapping and stabilizing certain unstable drug molecules, offering benefits and application possibilities. One kind of cyclodextrin particle with characteristic shapes of dicyclodextrin channel moieties and parallel tubular cavities, which was synthesized by a facile process. Subsequently, the spatial structure and characteristics of the β-CD-POF(I) were primarily confirmed. The structure of β-CD-POF(I) was then compared to that of KOH-β-CD-MOF, and a better material for vitamin A palmitate (VAP) encapsulation was determined. VAP was successfully loaded into the particles by solvent-free method. The arrangement of spatial structure made cyclodextrin molecular cavity encapsulation in β-CD-POF(I) more stable for VAP capture than that of KOH-β-CD-MOF.

Stability of vitamin A, E, C and thiamine during storage of different powdered enteral formulas

In this study, two different kinds of commercial enteral formulas were selected to evaluate the changes of vitamin A, E, C and thiamine during the different storage conditions of different temperature and relative humidity (60 ± 1 °C, 60 ± 5% for 5 and 10 days; 37 ± 1 °C, 75 ± 5% for 1, 2, 3, 5 and 6 months; 25 ± 1 °C, 60 ± 5% for 3, 6, 9, 12, 18 and 24 months). The results showed that as the temperature or time increased, the content of vitamin A, E and thiamine was gradually decreased whilst the level of vitamin C remained stable. The vitamins exhibited more stability at the storage of 25 ± 1 °C, RH 60 ± 5%. Vitamin A and thiamine decreased more in the polymeric formula (EFA) than that in the oligomeric formula (EFB), while, vitamin E decreased less in EFA than that in EFB. The kinetics of vitamin A, E and thiamine degradation during storage followed first order kinetic equations. Furthermore, the final levels of vitamins were higher than the minimum level recommended by legislation.