The stability of solid dispersions of felodipine in polyvinylpyrrolidone characterized by nanothermal analysis

Zhang, Jianxin; Bunker, Matthew; Parker, Andrew P.; Madden-Smith, Claire E.; Patel, Nikin; Roberts, Clive J.

doi:10.1016/j.ijpharm.2011.05.037

Cited by 61 publications

(21 citation statements)

References 25 publications

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“…The nanoscale softening temperature differed by 20°C from that of the macroscopic softening temperature, which was attributed to the thermal contact resistance of the thermal probe modulating the heat flow (Nelson and King 2007). Zhang et al (2011) demonstrated the use of AFM-nTA to detect instabilities in solid dispersions and to study the influence of environmental conditions on the physical stability of drugs.…”

Section: Afm-nanothermal Analysis In Polymer and Nanoscale Researchmentioning

confidence: 99%

Potential of AFM–nanothermal analysis to study the microscale thermal characteristics in soils and natural organic matter (NOM)

Schaumann

Mouvenchery

2011

J Soils Sediments

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Purpose This exploratory study evaluates the potential of nanothermal analysis (nTA) coupled with atomic force microscopy (AFM) of soil samples for understanding physicochemical processes in soil and for linking the nanospatial and microspatial distribution of thermal characteristics with the macroscopic properties of soil samples. Materials and methods Soil and reference samples were investigated by differential scanning calorimetry and AFMnTA. nTA was conducted on 16 points of each AFM image in two subsequent heating cycles (55-120°C and 55-300°C, respectively). Thermograms were subdivided into characteristic types and their spatial distribution was compared between sample replicates and materials. Results and discussion Thermogram types consisted of partly structured expansion and compression phases, suggesting material-specific thermal profiles. The distribution of thermogram types reflected sample-dependent nanoscale and microscale heterogeneity. Indications for water molecule bridge transitions were found by nTA in peat and soil. Organic materials generally revealed strong expansion and irreversible compression phases, latter probably due to the collapse of pore and aggregate structures. In contrast to charcoal and manure, peat shows strong expansion below 120°C and compression only above 120°C. Conclusions All investigated samples are heterogeneous on the nanoscale and microscale with respect to thermal behaviour. AFM-nTA allows distinguishing numerous different materials on nanometre and micrometre scales in soil samples. The material-dependent characteristics will help in understanding and learning more about the nanoscale distribution of different materials and properties. Related to the macroscopic thermal behaviour, this will allow studying links between the properties of biogeochemical interfaces and the processes governed by them.

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Section: Afm-nanothermal Analysis In Polymer and Nanoscale Researchmentioning

confidence: 99%

Potential of AFM–nanothermal analysis to study the microscale thermal characteristics in soils and natural organic matter (NOM)

Schaumann

Mouvenchery

2011

J Soils Sediments

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“…In the solid dispersion system, the solubility of drug can be improved by changing drug crystallinity to an amorphous state and by reducing particle size for better wettability. Different polymers are widely used as vehicles for solid dispersions [26,27] such as polyvinylpyrrolidone (PVP), poloxamers, and HP-β-CD, shown in Figure 1.…”

Section: Introductionmentioning

confidence: 99%

Molecular Interactions for the Curcumin-Polymer Complex with Enhanced Anti-Inflammatory Effects

Liu

Bian

et al. 2019

Pharmaceutics

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The molecular interactions between compound and polymeric carriers are expected to highly contribute to high drug load and good physical stability of solid dispersions. In this study, a series of amorphous solid dispersions (ASD) of Curcumin (Cur) were prepared with different polymers by the solvent evaporation method. With the carrier polyvinylpyrrolidone (PVP), the amorphous solid dispersion system exhibits a better solubility and stability than that with poloxamers and HP-β-CD due to the strong drug-polymer interaction. The drug/polymer interaction and their binding sites were investigated by combined experimental (XRD, DSC, FTIR, SEM, Raman, and 1H-NMR) and molecular dynamics simulation techniques. The Curcumin ASD demonstrated enhanced bioavailability by 11-fold and improved anti-inflammatory activities by the decrease in cytokine production (MMP-9, IL-1β, IL-6, VEGF, MIP-2, and TNF-α) compared to the raw Curcumin. The integration of experimental and modeling techniques is a powerful tool for the rational design of formulation development.

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“…In another study on a solid nano-dispersion of felodipinepolyvinylpyrrolidone (PVP), surface morphology could be visibly appreciated by nTA supported by AFM [25]. The formulation was subjected to 95% relative humidity and examined at 0, 1 and 3 days.…”

Section: Nanothermal Analysis (Nta) With Atomic Force Microscopy (Afm)mentioning

confidence: 99%

Recent Advances in Solid-State Analysis of Pharmaceuticals

Bukhari¹,

Hwei²,

Jantan³

2015

PHARMSCI

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Current analytical techniques for characterizing solid-state pharmaceuticals include powder x-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, infrared spectroscopy, Raman spectroscopy, electron microscopy and nuclear magnetic resonance. Powder x-ray diffraction and differential scanning calorimetry are mainstream techniques but they lack spatial resolution. Scanning electron microscopy and micro-Raman spectroscopy provide good chemical and optical characterization but they are not capable of analysing very small nanoparticles. Transmission electron microscopy and nano-thermal analysis can provide explicit characterization of nanoparticles but they are invasive. Nuclear magnetic resonance offers good spatial resolution but its use is mainly limited by poor sensitivity and high costs. In view of the many challenges posed by existing methods, new and novel techniques are being continually researched and developed to cater to the growing number of solid formulations in the pipeline and in the market. Some of the recent advances attained in the solid-state analysis of pharmaceutical are summarized in this review article.

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The stability of solid dispersions of felodipine in polyvinylpyrrolidone characterized by nanothermal analysis

Cited by 61 publications

References 25 publications

Potential of AFM–nanothermal analysis to study the microscale thermal characteristics in soils and natural organic matter (NOM)

Potential of AFM–nanothermal analysis to study the microscale thermal characteristics in soils and natural organic matter (NOM)

Molecular Interactions for the Curcumin-Polymer Complex with Enhanced Anti-Inflammatory Effects

Recent Advances in Solid-State Analysis of Pharmaceuticals

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