Temperature responsive hydroxypropyl cellulose for encapsulation

Heitfeld, Kevin; Guo, Tingtai; Yang, Guang; Schaefer, Dale W.

doi:10.1016/j.msec.2007.04.012

Cited by 31 publications

(15 citation statements)

References 12 publications

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“…In agriculture, temperature-responsive polymers have been investigated as pesticide carriers, as the release rate can be controlled to meet the requirements of pest prevention [25,26]. Poly(N-isopropylacrylamide) (PNIPAAm) is a typical temperature-responsive polymer, exhibiting a temperature-dependent volume phase transition near the lower critical solution temperature (LCST) in aqueous solution [27,28]. As PNIPAAm chains contain both hydrophilic and hydrophobic groups, PNIPAAm gel exhibits thermoreversible phase separation upon the temperature cycle across the LCST [29].…”

Section: Introductionmentioning

confidence: 99%

Thermosensitive Hydrogel for Encapsulation and Controlled Release of Biocontrol Agents to Prevent Peanut Aflatoxin Contamination

et al. 2020

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Starch, alginate, and poly(N-isopropylacrylamide) (PNIPAAm) were combined to prepare a semi-interpenetrating network (IPN) hydrogel with temperature sensitivity. Calcium chloride was used as cross-linking agent, the non-toxigenic Aspergillus flavus spores were successfully encapsulated as biocontrol agents by the method of ionic gelation. Characterization of the hydrogel was performed by Fourier-transform infrared spectroscopy (FTIR), scanning electron micrograph (SEM), and thermogravimetry analysis (TGA). Formulation characteristics, such as entrapment efficiency, beads size, swelling behavior, and rheological properties were evaluated. The optical and rheological measurements indicated that the lower critical solution temperature (LCST) of the samples was about 29–30 °C. TGA results demonstrated that the addition of kaolin could improve the thermal stability of the semi-IPN hydrogel. Morphological analysis showed a porous honeycomb structure on the surface of the beads. According to the release properties of the beads, the semi-IPN hydrogel beads containing kaolin not only have the effect of slow release before peanut flowering, but they also can rapidly release biocontrol agents after flowering begins. The early flowering stage of the peanut is the critical moment to apply biocontrol agents. Temperature-sensitive hydrogel beads containing kaolin could be considered as carriers of biocontrol agents for the control of aflatoxin in peanuts.

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Section: Introductionmentioning

confidence: 99%

Thermosensitive Hydrogel for Encapsulation and Controlled Release of Biocontrol Agents to Prevent Peanut Aflatoxin Contamination

et al. 2020

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“…Subsequent to this, a slow release rate (up to about 85.8% released) up to 300 min was observed. Heitfeld et al 27 reported the release behaviors of acetophenone-loaded HPC microcapsules prepared by the O/W/O emulsion method. They indicated that the HPC microcapsules showed rapid drug release behaviors within 14 min.…”

Section: Resultsmentioning

confidence: 99%

Influence of glyceryl palmitostearate on release behaviors of hydroxypropyl cellulose microcapsules containing indomethacin by W/O emulsion

Kim

Park

2011

Macromol. Res.

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Hydrophilic hydroxypropyl cellulose (HPC) microcapsules containing the indomethacin model drug were prepared using the water in oil (W/O) emulsion method. The effect of hydrophobic glyceryl palmitostearate (Precirol ATO 5) on the release behavior as well as the drug loading and encapsulation efficiency of the indomethacin-loaded microcapsules was investigated as a function of the Precirol ATO 5 content. The microcapsules formed showed stable and spherical forms, whose particle sizes ranged from about 20 to 152 µm. X-ray diffraction analyses indicate that the indomethacin in the microcapsules was distributed in the form of molecular or very small crystals. The drug loading and encapsulation efficiency of the microcapsules slightly increased with increasing surfactant and Precirol ATO 5 content. In the dissolution test, pure HPC microcapsules showed rapid drug release, whereas HPC microcapsules containing Precirol ATO 5 showed a slower release rate. This behavior might be attributable to the hydrophobic Precirol ATO 5 coating on indomethacin, leading to the delayed effect on drug release in the medium.

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“…The original viscosities of the tested beverages were regulated by adding hydroxypropyl cellulose (HPC), which is a derivative of polysaccharide cellulose and widely used in food, drug and cosmetics areas to obtain targeted viscosity of products [24]. The set up of the present study allowed the free flow of soft drinks over the surface of enamel specimens, so that the flow rate of the drinks were not defined by any pump system, rather it was determined by the viscosity of the liquid itself.…”

Section: Discussionmentioning

confidence: 99%

In vitro evaluation of the erosive potential of viscosity-modified soft acidic drinks on enamel

et al. 2013

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OBJECTIVE: The objective of this in vitro study was to investigate the effect of viscositymodified soft acidic drinks on enamel erosion. MATERIALS AND METHODS: A total of 108 bovine enamel samples ( = 3 mm) were embedded in acrylic resin and allocated into six groups (n = 18). Soft acidic drinks (orange juice, Coca-Cola, Sprite) were used both in their regular forms and at a kinetic viscositiy of 5 mm(2)/s, which was adjusted by adding hydroxypropyl cellulose. All solutions were pumped over the enamel surface from a reservoir with a drop rate of 3 ml/min. Each specimen was eroded for 10 min at 20°C. Erosion of enamel surfaces was measured using profilometry. Data were analyzed using independent t tests and one-way ANOVAs (p < 0.05). RESULTS: Enamel loss was significantly higher for the regular (Coca-Cola, 5.60 ± 1.04 m; Sprite, 5.49 ± 0.94 m; orange juice, 1.35 ± 0.4 m) than for the viscosity-modified drinks (Coca-Cola, 4.90 ± 0.34 m; Sprite, 4.46 ± 0.39 m; orange juice, 1.10 ± 0.22 m). CONCLUSION: For both regular and viscosity-modified forms, Coca-Cola and Sprite caused higher enamel loss than orange juice. Increasing the viscosity of acidic soft drinks to 5 mm(2)/s reduced enamel erosion by 12.6-18.7 %. CLINICAL RELEVANCE: The erosive potential of soft acidic drinks is not only dependent on various chemical properties but also on the viscosity of the acidic solution and can be reduced by viscosity modification. ABSTRACTObjective The objective of this in vitro study was to investigate the effect of viscosity-modified soft acidic drinks on enamel erosion. Materials and Methods A total of 108 bovine enamel samples (∅=3 mm) were embedded in acrylic resin and allocated to 6 groups (n=18). Soft acidic drinks (orange juice, Coca-Cola, Sprite) were used both in their regular forms and at a kinetic viscositiy of 5 mm 2 /s, which was adjusted by adding hydroxypropyl cellulose (HPC). All solutions were pumped over the enamel surface from a reservoir with a drop rate of 3ml/min. Each specimen was eroded for 10 min at 20°C.Erosion of enamel surfaces was measured using profilometry. Data were analyzed using independent t-tests and one-way ANOVAs (p<0.05). Results

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Temperature responsive hydroxypropyl cellulose for encapsulation

Cited by 31 publications

References 12 publications

Thermosensitive Hydrogel for Encapsulation and Controlled Release of Biocontrol Agents to Prevent Peanut Aflatoxin Contamination

Thermosensitive Hydrogel for Encapsulation and Controlled Release of Biocontrol Agents to Prevent Peanut Aflatoxin Contamination

Influence of glyceryl palmitostearate on release behaviors of hydroxypropyl cellulose microcapsules containing indomethacin by W/O emulsion

In vitro evaluation of the erosive potential of viscosity-modified soft acidic drinks on enamel

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