Study on the thermal decomposition mechanism of Mg(NO
 3
 )
 2
 ·6H
 2
 O from the perspective of resource utilization of magnesium slag

Zhang, Meng-Hui; Zhao, Liang; Xu, Han-Lu; Wu, Wenchang; Dong, Hua

doi:10.1080/09593330.2022.2121182

Cited by 2 publications

(2 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The thermal decomposition of ST occurs within the 330-410 • C temperature range, also identified by other researchers by thermogravimetric analysis under similar conditions [37]. This step may be linked to the denitrification process, which consists of the NO 2 and O 2 removal and forming MgO [37].…”

Section: Thermal Characterizationsupporting

confidence: 53%

New Hydrophilic Matrix Tablets for the Controlled Released of Chlorzoxazone

Creteanu,

Lisa,

Vasile

et al. 2024

IJMS

View full text Add to dashboard Cite

The modified release of active substances such as chlorzoxazone from matrix tablets, based on Kollidon®SR and chitosan, depends both on the drug solubility in the dissolution medium and on the matrix composition. The aim of this study is to obtain some new oral matrix tablet formulations, based on Kollidon®SR and chitosan, in order to optimize the low-dose oral bioavailability of chlorzoxazone, a non-steroidal anti-inflammatory drug of class II Biopharmaceutical Classification System. Nine types of chlorzoxazone matrix tablets were obtained using the direct compression method by varying the components ratio as 1:1, 1:2, and 1:3 chlorzoxazone/excipients, 20–40 w/w % Kollidon®SR, 3–7 w/w % chitosan while the auxiliary substances: Aerosil® 1 w/w %, magnesium stearate 0.5 w/w % and Avicel® up to 100 w/w % were kept in constant concentrations. Pharmaco-technical characterization of the tablets included the analysis of flowability and compressibility properties (flow time, friction coefficient, angle of repose, Hausner ratio, and Carr index), and pharmaco-chemical characteristics (such as mass and dose uniformity, thickness, diameter, mechanical strength, friability, softening degree, and in vitro release profiles). Based on the obtained results, only three matrix tablet formulations (F1b, F2b, and F3b, containing 30 w/w % KOL and 5 w/w % CHT, were selected and further tested. These formulations were studied in detail by Fourier-transform infrared spectrometry, X-ray diffraction, thermogravimetry, and differential scanning calorimetry. The three formulations were comparatively studied regarding the release kinetics of active substances using in vitro release testing. The results were analyzed by fitting into four representative mathematical models for the modified-release oral formulations. In vitro kinetic study revealed a complex mechanism of release occurring in two steps of drug release, the first step (0–2 h) and the second (2–36 h). Two factors were calculated to assess the release profile of chlorzoxazone: f1—the similarity factor, and f2—the factor difference. The results have shown that both Kollidon®SR and chitosan may be used as matrix-forming agents when combined with chlorzoxazone. The three formulations showed optima pharmaco-technical properties and in vitro kinetic behavior; therefore, they have tremendous potential to be used in oral pharmaceutical products for the controlled delivery of chlorzoxazone. In vitro dissolution tests revealed a faster drug release for the F2b sample.

show abstract

Section: Thermal Characterizationsupporting

confidence: 53%

New Hydrophilic Matrix Tablets for the Controlled Released of Chlorzoxazone

Creteanu,

Lisa,

Vasile

et al. 2024

IJMS

View full text Add to dashboard Cite

show abstract

“…The KOL sample contains 3.75% moisture, which is removed up to 80ºC. This sample's most significant mass loss occurs within the 320 -361°C temperature range and is due to the deacetylation of polyvinyl acetate present in KOL [36]. The mass loss recorded within the 416 -473°C temperature range amounts to 32.49%, which may be linked to the production of aromatic hydrocarbons [37], but also to the depolymerization of polyvinylpyrrolidone present in a smaller amount in KOL [38].…”

Section: X-ray Diffraction Analysismentioning

confidence: 99%

Formulation and Evaluation of Hydrophilic Matrix Tablets for Controlled Released Chlorzoxazone Delivery

Creteanu,

Lisa,

Vasile

et al. 2024

Preprint

View full text Add to dashboard Cite

The release of the active substance from the matrix modified-release tablets based on Kollidon®SR and chitosan depends on its solubility in the dissolution medium and on the composition of the matrix-forming polymers. The study is based on new oral matrix tablets based on Kollidon®SR and chitosan, formulated to optimize the low oral bioavailability of chlorzoxazone, a non-steroidal anti-inflammatory drug, a class II Biopharmaceutical Classification System. Nine types of chlorzoxazone matrix tablets were obtained using the direct compression method, and their combination at 1:1, 1:2, 1:3 chlorzoxazone/ excipients, 20%-40% (w/w) Kollidon®SR, 3-7% (w/w) chitosan and the auxiliary substances were formulated in constant concentrations. Pharmaco-technical characterization included the analysis of flowability and compressibility properties (flow time, friction coefficient, angle of repose, Hausner ratio, Carr Index), and of pharmaco-chemical characteristics (mass and dose uniformity, thickness, diameter, mechanical strength, Friability, degree of softening, in vitro release profile) of the tablets. Based on the initial evaluation of the pharmaco-technical analysis, pharmaco-chemical characteristics, and in vitro release profile, only three matrix tablet formulations (F1b, F2b, and F3b) were further tested. They were evaluated through Fourier-transform infrared spectrometry, X-ray Diffraction, thermogravimetry, differential scanning calorimetry, and in vitro dissolution tests. The three formulations were comparatively studied regarding the release kinetics of active substances using in vitro release testing. The results were analyzed by fitting into four representative mathematical models for the modified release oral formulations. In vitro kinetic study reveals a complex mechanism of release occurring in the first (0 - 2 hours) and second (2.0 hours – 36 hours) steps of drug release. Two factors have been calculated to assess the release profile of chlorzoxazone: f1 - the similarity factor and f2 - the factor difference. The results have shown that both Kollidon®SR and chitosan may be used as matrix-forming agents when combined with chlorzoxazone. In vitro dissolution tests revealed the F2b sample, data suggesting a faster drug release. The three formulations showed optimum pharmaco-technical properties and in vitro kinetic study, and they had tremendous potential to be used in oral pharmaceutical products for the controlled delivery of chlorzoxazone.

show abstract

Study on the thermal decomposition mechanism of Mg(NO ₃ ) ₂ ·6H ₂ O from the perspective of resource utilization of magnesium slag

Cited by 2 publications

References 36 publications

New Hydrophilic Matrix Tablets for the Controlled Released of Chlorzoxazone

New Hydrophilic Matrix Tablets for the Controlled Released of Chlorzoxazone

Formulation and Evaluation of Hydrophilic Matrix Tablets for Controlled Released Chlorzoxazone Delivery

Contact Info

Product

Resources

About

Study on the thermal decomposition mechanism of Mg(NO 3 ) 2 ·6H 2 O from the perspective of resource utilization of magnesium slag

Cited by 2 publications

References 36 publications

New Hydrophilic Matrix Tablets for the Controlled Released of Chlorzoxazone

New Hydrophilic Matrix Tablets for the Controlled Released of Chlorzoxazone

Formulation and Evaluation of Hydrophilic Matrix Tablets for Controlled Released Chlorzoxazone Delivery

Contact Info

Product

Resources

About

Study on the thermal decomposition mechanism of Mg(NO ₃ ) ₂ ·6H ₂ O from the perspective of resource utilization of magnesium slag