Characterization of physical and viscoelastic properties of polymer films for coating applications under different temperature of drying and storage

Perfetti, G.; Jansen, K.M.B.; Wildeboer, W.J.; Hee, P. van; Meesters, G.M.H.

doi:10.1016/j.ijpharm.2009.10.007

Cited by 24 publications

(13 citation statements)

References 28 publications

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“…CD gels show relatively smooth surfaces with slight differences between the three gelation temperatures (T gel = 4, 20 and 30 °C). Perfetti et al [28] also did not found significant differences in a study that aimed to evaluate the effect of drying temperature on the morphology of PVA cast films (from room temperature to 70 °C).…”

Section: Resultsmentioning

confidence: 99%

Tribomechanical Comparison between PVA Hydrogels Obtained Using Different Processing Conditions and Human Cartilage

et al. 2019

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Designing materials for cartilage replacement raises several challenges due to the complexity of the natural tissue and its unique tribomechanical properties. Poly(vinyl alcohol) (PVA) hydrogels have been explored for such purpose since they are biocompatible, present high chemical stability, and their properties may be tailored through different strategies. In this work, the influence of preparation conditions of PVA hydrogels on its morphology, water absorption capacity, thermotropic behavior, mechanical properties, and tribological performance was evaluated and compared with those of human cartilage (HC). The hydrogels were obtained by cast-drying (CD) and freeze-thawing (FT), in various conditions. It was found that the method of preparation of the PVA hydrogels critically affects their microstructure and performance. CD gels presented a denser structure, absorbed less water, were stiffer, dissipated less energy, and withstood higher loads than FT gels. Moreover, they led to friction coefficients against stainless steel comparable with those of HC. Overall, CD hydrogels had a closer performance to natural HC, when compared to FT ones.

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Section: Resultsmentioning

confidence: 99%

Tribomechanical Comparison between PVA Hydrogels Obtained Using Different Processing Conditions and Human Cartilage

et al. 2019

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“…A comprehensive understanding of the mechanisms involved during film formation is lacking as are methods of characterizing film coatings. Some authors reported studies on isolated films to assess the influence of formulation and process parameters on film coating quality [7,8]. However, it was shown that film properties differ from those of film coatings when applied to substrates [9].…”

Section: Introductionmentioning

confidence: 99%

Comprehensive study of dynamic curing effect on tablet coating structure

Gendre

Genty

Silva

et al. 2012

European Journal of Pharmaceutics and Biopharmaceutics

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The dissolution method is still widely used to determine curing end-points to ensure long-term stability of film coatings. Nevertheless, the process of curing has not yet been fully investigated. For the first time, joint techniques were used to elucidate the mechanisms of dynamic curing over time from ethylcellulose (Aquacoat)-based coated tablets. X-ray micro-computed tomography (XμCT), Near Infrared (NIR), and Raman spectroscopies as well as X-ray microdiffraction were employed as non-destructive techniques to perform direct measurements on tablets. All techniques indicated that after a dynamic curing period of 4h, reproducible drug release can be achieved and no changes in the microstructure of the coating were any longer detected. XμCT analysis highlighted the reduced internal porosity, while both NIR and Raman measurements showed that spectral information remained unaltered after further curing. X-ray microdiffraction revealed densification of the coating layer with a decrease in the overall coating thickness of about 10 μm as a result of curing. In addition, coating heterogeneity attributed to cetyl alcohol was observed from microscopic images and Raman analysis. This observation was confirmed by X-ray microdiffraction that showed that crystalline cetyl alcohol melted and spread over the coating surface with curing. Prior to curing, X-ray microdiffraction also revealed the existence of two coating zones differing in crystalline cetyl alcohol and sodium lauryl sulfate concentrations which could be explained by migration of these constituents within the coating layer. Therefore, the use of non-destructive techniques allowed new insights into tablet coating structures and provided precise determination of the curing end-point compared to traditional dissolution testing. This thorough study may open up new possibilities for process and formulation control.

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“…The relative standard deviation (RSD) of the measurement results in Figure 2 were listed in Table 1. All the RSD values are less than 5%, which indicates that the SEC method performed is accurate and reliable [26]. PDI is defined as the ratio of M w to M n [27].…”

Section: Measurement Of Molecular Weightmentioning

confidence: 94%

“…The thermogravimetric curve of starch is shown in Figure 4. It can be seen that the starch had undergone three stages of decomposition, the main mass loss occurred in the temperature range of 264-337 °C and the weight loss rate was up to 68% at 316 °C [26]. The thermogravimetric curve of the PAA-AM is shown in Figure 5.…”

Section: Thermal Stabilitymentioning

confidence: 98%

Preparation of Poly(acrylic acid-acrylamide/starch) Composite and Its Adsorption Properties for Mercury (II)

et al. 2021

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The poly (acrylic acid-acrylamide/starch) composite was synthesized by solution polymerization, aiming to adsorb mercury (II) in water. The resulted copolymer was characterized by particle size exclusion chromatography (SEC), Fourier transform infrared spectroscopy (FTIR), thermogravimetry (TG), scanning electron microscopy (SEM) and dynamic light scattering particle size analyzer (DLS). It turned out that starch was successfully incorporated with the macromolecular polymer matrix and played a key role for improving the performance of the composites. These characterization results showed that the graft copolymer exhibited narrow molecular weight distribution, rough but uniform morphology, good thermal stability and narrow particle size distribution. The graft copolymer was used to remove Hg(II) ions from aqueous solution. The effects of contact time, pH value, initial mercury (II) concentration and temperature on the adsorption capacity of Hg(II) ions were researched. It was found that after 120 min of interaction, poly (acrylic acid-acrylamide/starch) composite achieved the maximum adsorption capacity of 19.23 mg·g−1 to Hg(II) ions with initial concentration of 15 mg·L−1, pH of 5.5 at 45 °C. Compared with other studies with the same purpose, the composites synthesized in this study present high adsorption properties for Hg(II) ion in dilute solution. The adsorption kinetics of Hg(II) on the poly (acrylic acid-acrylamide/starch) composite fits well with the pseudo second order model.

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Characterization of physical and viscoelastic properties of polymer films for coating applications under different temperature of drying and storage

Cited by 24 publications

References 28 publications

Tribomechanical Comparison between PVA Hydrogels Obtained Using Different Processing Conditions and Human Cartilage

Tribomechanical Comparison between PVA Hydrogels Obtained Using Different Processing Conditions and Human Cartilage

Comprehensive study of dynamic curing effect on tablet coating structure

Preparation of Poly(acrylic acid-acrylamide/starch) Composite and Its Adsorption Properties for Mercury (II)

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